GeoWorld 8

arid landscapes: very dry places where evaporation exceeds low precipitation

coastal landscapes: dynamic zones of interaction between sea and land

coral reefs: biological landforms created by coral polypsdepositional landforms: formed when geomorphic processes

deposit sedimentserosional landforms: formed when geomorphic processes wear

down Earth’s surfaceglaciers: dynamic, large, moving bodies of compacted ice that

exist for long periods of time

ice sheets: glaciers that cover vast areaskarst: distinctive topography that indicates dissolution of soluble

rocks by surface water or ground water mountains: landforms greater than 600 m that were created by

tectonic activityplains: level, gently undulating surfaces, either coastal, inland or on

the sea floorplateaus: large, relatively level areas rising more than 450 m above

the surroundingsrelic landform: formed during a previous time or climate or

resulting from tectonic activity

chap

ter Distinctive landform

features: values and protection

… seen from above, landscapes are made up of mountains and watercourses. Just as a transparent model of the human body consists of a framework of bone and a network of arteries, the Earth’s crust is structured in mountain ridges, rivers, creeks, and gullies.

Stefan Dech and Reinhold Messner

1

Geovocab

[Insert aw 01001]

200913_GeoWorld8AC_01_1pp.indd 4 11/10/13 9:58 AM

sinkholes: closed surface depression draining underground in a karst landscape

speleothems: deposits of calcium carbonate, formed in caves by chemical precipitation from drips or thin films of water

stalactite: hangs downwards from a roof or wall of a cavestalagmite: projects vertically upwards from a cave floortectonic activity: movement in Earth’s crustterrestrial: found on landWorld Heritage Site: special internationally protected areas of

universal value

Landscapes are areas of Earth’s surface created by combinations of geological and biological activity that have evolved over time. They are perceived, valued and protected in different ways by different cultures. Landscapes and their distinctive landforms are complex, dynamic and vary in scale. They provide a valuable means of investigating the physical environment, its changes over time and space, and its interconnections.

Think, puzzle, explore

• Place Where are landscapes and their distinctive landforms located?

• Space How do landforms vary over space?• Environment How does the environment change

landforms?• Interconnection How are landscapes and

landforms interconnected?• Sustainability How can humans use landforms in

a sustainable way?• Scale How do landforms vary from the local to

global scale?• Change How have landforms changed over time?

Geoskills in focus

• Observing the variety of landforms and their changes over time using the inquiry process

• Collecting and analysing relevant geographical data on landforms and their changes over time

• Concluding that landforms are combinations of features that exist at a variety of scales and interconnectivity

• Reflecting on the complexity of landforms and the need for their protection

Horseshoe Bend meander on the Colorado River, Arizona, USA


ISBN 978 1 4202 3265 36

GeoWorld 8: Australian Curriculum

1.1 Landscapes and landforms: scale and interconnections

From space, Earth looks like a blue marble because 71% of its surface is covered by oceans. Modern satellite imagery has enabled us to map and analyse Earth’s distinctive landscapes—both submarine (sea) and terrestrial (land)—in great detail. The unique perspectives from satellite imagery and radar technology also enable us to see the interconnections between landscapes at a range of scales.

1.1.1 Landscapes and distinctive landforms: scale and interconnections

Scale Example

Macro Earth—planet• ocean (71% of land surface)• land (29% of land surface)

Meso Landscapes—submarine and terrestrial• submarine: continental shelf, abyssal plain,

trench, mid-oceanic ridge, guyot• terrestrial: coastal, riverine, wetland, mountain,

plain, arid, volcanic, karst

Landforms—submarine and terrestrial• larger components of landscapes• may form part of a larger, extensive system,

e.g. mountain range or a barrier beach• unique features of the landforms, e.g. elevation

or sediment type

Micro Individual landforms—submarine and terrestrial• smaller components of landforms• isolated landform, e.g. a volcano or a spit• unique features of a landform e.g. mud flow

from a volcano or a re-curved spit

Macro- and meso-scaleThe surface of Earth is naturally divided into two broad landscapes: oceans and land. Each has distinctive landforms. Digital elevation model images of Earth’s surface show the major landscapes with distinctive landform features such as mountains, plateaus and plains. Submarine landforms mirror those found on land, but are much larger and have different names, such as mid-ocean ridges and abyssal plains.

Micro-scale landformsAt the micro-scale, it is possible to examine individual landforms, both submarine and terrestrial. At a larger scale, the unique features

[Insert aw 01003 (Australia) and aw 01004 (Mainland USA) next to it]

1.1.2 Digital elevation model map showing the major landforms of Australia and mainland USA

1.1.2 Satellite image of Earth showing oceans and land

[re-instate this image to fill space?]


ISBN 978 1 4202 3265 3

Distinctive landform features: values and protection

7

Ch

ap

ter 1

of a landform can be studied in detail. It is also possible using a micro-scale approach to study a part of a meso-scale landform, such as Mt Everest in the Himalayan Mountains.

Ghost mountains and subglacial lakesAs well as mapping the landforms on land and in the deepest oceans, scientists have revealed the secrets of mountains and lakes buried under the Antarctic ice sheet. The Gamburtsev Subglacial Mountains, known as the Ghost Mountains, are buried under more than a kilometre of ice beneath the East Antarctica Ice Sheet. They lie under the 4000 m high Dome A, the highest point in Antarctica. Scientists have also located and mapped thousands of subglacial lakes in Antarctica, the largest of which is Lake Vostok.

Geoactivities 1.1

Knowledge and understanding

1 How does technology help study landscapes and their distinctive landform features?

2 What are meso-scale landscapes? 3 What is a micro-scale landscape? 4 What are the ghost mountains and subglacial

lakes?

Inquiry and skills

5 Refer to 1.1.2. a Map the following broad landscapes in Australia

using different colours and a legend: mountains, plateaus, plains.

b Use an atlas or the internet to label the specific landforms on your map.

7 Use MapMaker Interactive to explore a section of the ocean floor. How does this interactive help your understanding of submarine landscapes?

[Insert aw 01007]

1.1.3 Digital elevation model 3D image of Cotopaxi Volcano in the Andes Mountains, Ecuador. The volcano is 5897 m high—more than 3000 m higher than the surroundings. The volcano is about 23 km wide at its base and mud flows (lahars) can be seen around it

[Insert aw 01008]

1.1.4 This 3D image shows the Gamburtsev Subglacial Mountains

Geoinfo

The German Aerospace Centre’s TanDEM-X mission is creating a 3D elevation model of Earth’s surface that is accurate to within a few metres.


ISBN 978 1 4202 3265 38


1.2 Values of landscapes and landforms

Unique landscapes and their distinctive landforms are often highly valued for a multitude of reasons, such as their economic and recreational value as tourist attractions. Some landscapes and landforms, such as the Great Barrier Reef and the Giant’s Causeway in Northern Ireland, are protected at local, national and global scales because of their environmental or cultural significance to present and future generations.

[Insert aw 01010]

1.2.2 The hexagonal basaltic prisms of the Giants’ Causeway, Antrim, Northern Ireland, have mythological value to the Celtic people. They are also excellent examples of volcanic landscapes

[Insert aw 01011]

1.2.3 Lizard Island and Blue Lagoon provide examples of the aesthetic value of the Great Barrier Reef, Queensland

Aesthetic valuesThe aesthetic (beauty) values of landscapes and landforms are based on the relationship between the characteristics of the landscape and the effect these have on a human observer. Even though different people and cultures perceive landscapes and

Relatively tangible and objective values

(e.g. economic, historical, ecological

and recreation)

More intangible and subjective values (e.g. aesthetic, mythological, wilderness and spiritual)

1.2.1 People’s values towards landscapes and landforms form a continuum

landforms differently, there is a general level of agreement on what makes a place aesthetically valuable. These places are often scenic natural environments with vistas and outstanding or unusual landscapes and landforms.


ISBN 978 1 4202 3265 3


9

Ch

ap

ter 1

Geoactivities 1.2


1 Explain why people’s values towards landscapes and landforms form a continuum.

2 Explain why some landscapes and distinctive landforms have multiple values for people.

3 What are aesthetic values and how do they vary? 4 What are cultural values and how do they differ

from other values? 5 Discuss the spiritual values of landscapes and

landforms held by a variety of communities.

Inquiry and skills

6 Refer to 1.2.1. Use a table to match the values with examples of landscapes and landforms in Australia and overseas.

7 Research two World Heritage Sites that focus on landforms from different countries. Outline the physical and cultural criteria for their listing. Explain how these reflect social values.

8 Outline suggestions to resolve potential conflict in national parks and marine parks over issues such as mining, hunting and commercial fishing. Select examples from Asia and/or Indigenous land issues.

9 Imagine you are at a spiritually significant site, for example Uluru at sunset. Write a 200 word report for a newspaper on your experience.

[Insert aw 01012]

1.2.4 Mount Fuji and Lake Kawaguchi have great cultural significance to the Japanese

Cultural valuesThe cultural values of landscapes and landforms are values shared by a group or community—or are assigned by experts or governments on their behalf. They include not only traditional myths and stories, but also landscapes and landforms that society values, such as volcanoes, rivers, lakes and coastlines.

1.2.5 Aerial view of a cenote—the entrance to one of more than 2200 mapped underwater caves in the Yucatan Peninsula, Mexico

[Insert aw 01013]

Geoinfo

The Ganges River in India is revered by millions of Hindus as a symbol of spiritual purity.

Spiritual valuesMost cultures assign spiritual value to landscapes and landforms. Scared landforms include rivers, waterfalls, lakes, wetlands and cliffs. Aboriginal and Torres Strait Islander Peoples hold deep spiritual values towards the landscape because they believe ancestral beings created the landform features in the Dreaming. The Jewish and Christian faiths hold Mount Sinai in Egypt to be sacred because they believe this is the site where God gave Moses the Ten Commandments. The Mayans of the Yucatan Peninsula in Mexico believe that cenotes (vertical sinkhole filled with fresh water) and caves are spiritually significant, and they are the entrances to the underworld where the Mayan gods and ancestors can be contacted.


ISBN 978 1 4202 3265 310


1.3 The Dreaming: values and meanings of landscapes to Aboriginal and Torres Strait Islander Peoples

every Aboriginal group had the same Dreaming as the stories generally focus on the local landscape. For example:

• Wandjina in the Kimberley area of Western Australia created landscapes and its inhabitants. When their earthly tasks were completed, they painted their images on cave walls then disappeared into a nearby waterhole.

For Aboriginal and Torres Strait Islander Peoples, the Dreaming (or Dreamtime) is when all things began—the landscape was created by ancestral beings who wandered Earth during the Dreaming. This history is passed down by word of mouth as Dreaming stories or songlines. These stories recount journeys across Earth by ancestral spirits, which created humans, plants and animals—and on these journeys landforms were left behind, such as Uluru and the Devil’s Marbles. For example, the Bidjara and Karingbal people see the Rainbow Serpent’s power in Carnarvon Gorge in Queensland, where it carved a path in the sandstone to create creeks. The Dreaming’s ancestral spirits made rules to govern the land, and if life on Earth was to continue, these rules were to be followed.

Aboriginal and Torres Strait Islander Peoples view the landscape in a coherent, holistic (interconnected) way rather than viewing it as separate components, and they have multilayered meanings associated with the landscape because it supports their material, cultural and spiritual wellbeing.

The Dreaming and interconnectionThe Dreaming describes the period when spirits emerged from the ground, sky and sea to create landforms and living things over a featureless Earth. Paul Morin’s Aboriginal Dreamtime story stated that

The Australian Aborigines believe that long ago the Earth was soft and had no form. The features of the landscape were created as the result of the heroic acts of ancestral spirits, who often assumed the form of animals. The origins of land shapes—mountains, deserts and water holes—echo these events, which the Aborigines refer to as Dreamtime. For at least fifty thousand years, the Aborigines have maintained the traditions of Dreamtime through stories, music, dance, art, and ceremony.

Dreaming is preserved in Aboriginal paintings, which resemble maps depicting different landscapes and events from an aerial perspective. However, not

[Insert aw 01016]

1.3.2 Wandjina figures in rock art sites scattered throughout the western Kimberley

insert AW01121

1.3.1 Oblique aerial view of Uluru showing its distinctive shape


ISBN 978 1 4202 3265 3


11

Ch

ap

ter 1

• Jabreen in the Gold Coast area of Queensland was a huge man with large fingers. After he went to the beach to eat he stood up and stretched his arms toward the sky. The land followed his hands skyward forming Jellurgal or Burleigh Mountain.

Landforms became interconnected as the routes taken by creators in their Dreamtime journeys linked sacred sites. Some Dreaming tracks ran for thousands of kilometres through desert, rainforest and coastal landscapes.

Multilayered meaningsAboriginal and Torres Strait Islander Peoples hold multilayered meanings to different landscapes and landforms, which encompass material (food, shelter), cultural (ceremonies) and spiritual (burial sites) wellbeing. For example, a rock shelter may contain bone fragments, stone artefacts, rock art, and remains of meals and ceremonial activities.

Landforms such as limestone caves were popular sites for Aboriginal people. About 2000 years ago, the Wiradjuri and Gundungurra groups frequented Abercrombie Caves (NSW), which were a source of shelter, food and water. The Njunawal people in Bungonia National Park (NSW) left remains of their existence in caves indicating tool manufacturing and bone deposits signifying a burial site. The Bidewal and Ngunnawal groups in the Snowy Mountains used caves for shelter and a burial place.

There are a number of landscapes where Aboriginal myths match up with modern scientific discoveries. Lake Eye was accurately described as a continuous garden during the wet period of the Holocene epoch, and the coastline south of Cairns (which has since flooded) accurately described as meeting the edge of the Great Barrier Reef 10 00 years ago.

Due to the significant meanings of landscapes to Aboriginal and Torres Strait Islanders, some places have been declared World Heritage Sites, for example, Willandra Lakes Region, the Tasmanian Wilderness and Fraser Island.

1.3.4 Devils Marbles

[Insert AW01123]

1.3.3 UNESCO World Heritage landscapes of Aboriginal significance

Willandra Lakes Region (pictured)—arid lake landscapeContains ancient lakes formed over the last two million years. The region illustrates how Aboriginal communities adapted to local resources and changing natural environments. The remains of a 40 000 year old female was found in the dunes of Lake Mungo (believed to be the oldest ritual cremation site in the world) and 18 000 year old grindstones used to crush grass for flour.

Uluru-Kata Tjuta National Park—desert landscape UNESCO states that Tjukurpa, which is traditional religious philosophy, ‘provides an interpretation of the present landscape, flora, fauna and natural phenomena in terms of journeys and activities of ancestral beings and consequently binds people socially, spiritually and historically to the land’.

Fraser Island—coastal landscape Indicates remains of Badtjala and Kabi Kabi settlements, such as middens and canoes, dating back 1500–2000 years ago.

Purnululu National Park— sandstone landscape Has Aboriginal cultural heritage spanning back 20 000 years. Today, many of these people retain traditional land management practices and use the landscape for harvesting wild food.Wet Tropics Queensland—

rainforest landscape Aboriginal occupation between Cooktown and Cardwell dates back 40 000 years. The Barrineans or northern tribes are said to represent the first wave of the Aboriginal occupation in Australia.

Tasmanian Wilderness— forest landscape Contains 37 cave sites occupied between 30 000 and 11 500 years ago. Stone artefacts, quarries and rock shelters in Tasmanian highlands indicate Aboriginal adaptation to a subalpine environment.

Geoinfo

The Devils Marbles in the Northern Territory are the eggs that the Rainbow Serpent laid during the Dreaming.

[Insert AW01122]


ISBN 978 1 4202 3265 312


Management of Uluru by the Anangu peopleUluru–Kata Tjuta National Park was inscribed as a World Heritage Site for its cultural values and landforms—its spectacular geological formations, rare plants and animals and exceptional natural beauty. A major responsibility of a World Heritage listing is the sustainable management and protection of the site, which involves combining traditional Anangu land management with modern scientific methods.

The Anangu have looked after the Uluru landscape for tens of thousands of years. They have a long tradition of fire management, called waru (patch burning) beginning with the Lungkata (blue-tongued lizard) ancestral beings in the Tjukurpa who burned the spinifex on their way to Uluru. To avoid severe wildfires damaging the diversity of plants and animals in the park, and to maintain this diversity, the Anangu manage the patch burning with assistance from park rangers.

Another sensitive management issue is climbing Uluru. The Anangu believe that the path of the climb is the traditional route taken by the Mala men during the Tjukurpa. Due to this spiritual

Uluru—a sacred landformUluru is probably Australia’s most recognisable landform. It is a 348 m high sandstone inselberg located 465 km southwest of Alice Springs in an arid landscape. The term ‘inselberg’ is originally German for an ‘island mountain’. Uluru is a remnant of a mountain range that has resisted 300–400 million years of erosion since it was uplifted. It protrudes from the surrounding peneplain (relatively flat land surface produced by erosion). Geologists do not like to refer to Uluru as a monolith (single rock) because of its sedimentary origins.

Significance of Uluru to the Anangu peopleMany people regard Uluru as a national symbol of Australia. To the traditional Pitjantjatjara and Yankunytjatjara owners (known as Anangu), however, it is a sacred site and their home. In Anangu culture, Tjukurpa is the creation period when the world was made. The ancestors created the physical features of the landscape, which are called Tjukuritja. The Anangu believe that the landscape is still inhabited by ancestral beings and their spirits. Ancestor journeys across the landscape are called iwara (also called songlines). The stories and songs of ancestors can sometimes be traced for hundreds of kilometres. Tjukurpa underpins Anangu society and knowledge and connects everything. Three ancestors are considered important to the Uluru region: Mala (hare wallaby), Kuniya (woma python) and Liru (poisonous snake). Traditional Tjukurpa oral stories, rituals, ceremonies, art, songs and dances have been passed down for tens of thousands of years to keep Anangu culture alive.

1.3.5 Caves and rock art around the base of Uluru have great spiritual significance to the Anangu

[Insert aw 01017]

1.3.6 Formation of Ktjuta (Olgas) and Uluru

[Insert aw 01018 to be redrawn]


ISBN 978 1 4202 3265 3


13

Ch

ap

ter 1

significance, the Anangu prefer that visitors respect their laws and culture and not climb Uluru. More and more people are choosing this option. In 1990, 75% of visitors climbed Uluru, however in 2012 the number had fallen to 20%. The climb also poses a risk to personal safety as many people have died in falls. The lack of toilet facilities has also led to water pollution in waterholes after rainfall.

Geoactivities 1.3


1 What is meant by the Dreaming? 2 Discuss the connections between the Dreaming and

the landscape. 3 Explain how landscapes and landforms possess

multilayered meanings to Aboriginal and Torres Strait Islander Peoples.

4 Describe how traditional Aboriginal communities use natural resources such as rocks and soil.

5 Compare the significance of Uluru to the Anangu and the wider Australian community.

6 Describe why Uluru is sacred to the Anangu. 7 Explain the difference between Tjukurpa, Tjukuritja

and iwara. 8 Describe the Anangu tradition of waru. What are two

advantages of this practice? 9 Why don’t the Anangu want visitors to climb Uluru?

Inquiry and skills

10 Refer to 1.3.2. a What is distinctive about these figures? b What are the common colours?c In groups design a Wandjina Tour and include:

What you would see? What are the connections between culture and the land? Why do Aboriginal people of the Mowanjum tribes repaint the images each year?

11 Refer to 1.3.3. a Explain why these World Heritage sites are of

importance to indigenous Australians.b Collect photographs of these landscapes. Explain

the importance of sustainably managing these landscapes and landforms.

12 Investigate two Aboriginal Dreaming stories concerning the formation and meaning of landforms in your local area. Present as a Prezi.

13 Research the links between Aboriginal myths and scientific discovery concerning the Atherton Tableland, Crater Lakes, Port Phillip Bay and the Great Barrier Reef.

14 Refer to 1.3.6. a What is the estimated height of the Olgas and

Uluru above sea level?b What do the Olgas and Ayres Rock have in

common?c Explain how the Olgas became separate

landforms. 15 Refer to 1.3.7.

a Draw a cross section from A to B and from C to D.b Compare the different perspectives from the cross

sections. c Using Geocontext-Profiler on the internet draw a

topographic profile of Uluru. 16 Choose a landform in your local area that is

significant to Aboriginal and Torres Strait Islander Peoples. Describe the landform and outline why it is significant. Present as a Prezi.

17 Research the significance to Aboriginal and Torres Strait Islander Peoples of another iconic landform.

18 Discuss this statement: Landforms with special importance to Aboriginal and Torres Strait Islander Peoples need special protection.

19 Aboriginal people celebrate their culture at many events and festivals. In groups research three of the following festivals: Ord Valley Muster (WA), Laura Dance (Qld), the Dreaming Festival (Qld), Walking with the Spirits (NT), Yeperenye Dreaming (NT), Barunga Festival (NT), Yabun (NSW), Message Sticks (NSW), Spirit Festival (SA), Yalukit Willam Ngargee Festival (Vic). Discuss how these festivals are linked to the Dreaming and the landscape.

[Insert aw 01019]

1.3.7 Cross section of Uluru

Geoinfo

Aboriginal Peoples Dreaming stories reference climate change, extinct megafauna, sea level changes, volcanic eruptions, and even glaciations.


ISBN 978 1 4202 3265 314


1.4 Significance of landscapes and landforms to Australia

Landscapes are often generalised as the ‘bush’ or ‘outback’ in Australia. They thread through Australian culture and have been used to define our elusive ‘national identity’. The importance of landscapes and landforms to Australia builds on the ancient traditions of Aboriginal and Torres Strait Islander Peoples, such as the formation of the Three Sisters in the Blue Mountains in New South Wales—a World Heritage Site. According to Aboriginal legends, these rock formations represented three sisters who were turned to stone. People from the Gundungurra and Darug tribes consider the Three Sisters (which were once seven) to be sacred and are concerned that the thousands of climbers scaling the rocks each year are upsetting the sisters by causing erosion.

From another perspective, geologists state that over time the soft sandstone of the Blue Mountains was eroded by wind, rain and rivers, causing the cliffs to slowly break up—one of the remaining formations was the Three Sisters.

[Insert aw 01021]

1.4.1 The Three Sisters in the Blue Mountains is an iconic Australian landscape—the blue colour comes from vaporised oil from eucalyptus leaves

Australian literature and artLate nineteenth century poets and novelists, such as Henry Lawson and AB (Banjo) Paterson, wrote about the bush as a landscape that needed to be tamed by resourceful pioneers. By 1910, most Australians lived in urban areas, but they identified with the harsh landscapes of the bush and its larrikins. The Man from Snowy River is set in the high country of the Australian Alps, and Dorothea Mackellar’s My Country describes her feelings towards Australia through landscape images.

I love a sunburnt country, A land of sweeping plains, Of ragged mountain ranges, Of droughts and flooding rains. I love her far horizons, I love her jewel-sea, Her beauty and her terror – The wide brown land for me!

[Insert aw 01022]

1.4.2 How seven sisters became three—the other four lie in the valley below


ISBN 978 1 4202 3265 3


15

Ch

ap

ter 1

Dated up to 20 000 years old, Aboriginal rock art is said to be the oldest in the world. In recent years, international interest in traditional Aboriginal art has boomed, particularly in the highly symbolic Dreaming stories of landscapes.

Australian music, film and identityBush ballads with references to landscapes were extremely popular in the pioneering phase of Australia’s recent history, while modern music still refers to Australian landscapes. It’s raining on the Rock by John Williamson is about a storm over Uluru–Kata Tjuta; My Island Home by Christine Anu is about Elcho Island off Arnhem Land, but is a metaphor for Australia.

Stunning landscapes form the setting of many iconic Australian films, such as Crocodile Dundee (1986) and Australia (2008). The different perceptions of Aboriginal Peoples towards the landscape are explored in Rabbit Proof Fence (2002) and Ten Canoes (2006).

Landscapes depicted in Australian literature, art, music and film has been central to defining an Australian identity. Henry Lawson identified the struggle with the ‘bush’ as the core of the development of a distinctive Australian identity. Traditional Australian values of treating people equally, giving everyone a ‘fair go’, being strong in the face of hardship, and ‘mateship’ are believed to have been influenced by the landscape.

[Insert aw 01023]

1.4.3 Set on the banks of a billabong, Banjo Paterson’s Waltzing Matilda is Australia’s unofficial national anthem and the subject of this 1980 series of stamps

1.4.4 Sidney Nolan’s Musgrave Ranges is one of a series of paintings of central Australia with an aerial perspective, giving a new sense of scale to the outback

[Insert aw 01024]

Geoactivities 1.4


1 Outline how landforms and landscapes have been represented in Australian literature and art.

2 Give examples of landscapes in Australia music and film.

3 How have landscapes shaped an Australian identity?

Inquiry and skills

4 Refer to 1.4.2.a How were the Three Sisters formed according to

Aboriginal Dreamtime?b How do geologists describe the formation of the

Three Sisters?c Debate for and against climbing the Three

Sisters. 5 Refer to 1.4.4 and describe the landforms and

landscape. 6 Research the formation of the MacDonald Ranges

in the Northern Territory, which until 600 million years ago was covered by shallow seas.

7 Brainstorm other examples of Australian music that mention landscapes. Present as a Wordle.

8 Design a collage of Australia’s main landforms. Label the features and their locations.


ISBN 978 1 4202 3265 316


1.5 Submarine landscapes and distinctive landforms

Submarine landscapes occupy approximately 71% of Earth. Until recently, they were largely hidden and unknown. Submarine landscapes mirror similar features of continental landscapes, but on a larger scale. The following are major landforms located in oceans.

• Continental shelves and slopes—continental shelves are the submerged outer edges of the continents, which mostly consist of granites. Continental slopes are where the continental shelves start to merge with the oceanic crust, which is mainly basalt.

• Abyssal plains—the relatively level areas between continental margins and mid-oceanic ridges. They are usually located at depths of 4000–5000 m.

• Mid-oceanic ridges—every ocean has long, continuous volcanic mountain ranges called mid-oceanic ridges. As the oceanic crust pulls apart, magma seeps out in a continuous process called seafloor spreading. New oceanic crust is created at mid-oceanic ridges by lava flows as well as occasionally erupting volcanoes. About 75% of the magma reaching Earth’s surface comes from mid-oceanic ridges.

• Rift valleys—valley forming between the two spreading sections in the ocean floor.

1.5.1 Submarine landforms

[Insert aw 01027 to be redrawn with

corrections]

1.5.2 Mid-oceanic rift valleys

Type of mid-oceanic ridge

Rate of sea floor spreading

Cross-section profile

Slowly spreading ridges

1–5 cm/year Width: 10 km wide between the crests of the ridges on both sides. Depth: 3 km deep

Medium spreading ridges

5–10 cm/year Width: 5 km wide valleys between the crests of the ridges on both sides. Depth: 50–100 m deep

Rapidly spreading ridges

10–20 cm/year Width: 100 m wide valleys between the crests of the ridges on both sides. Depth: 10–20 m deep

1.5.3 Major trenches and mid-oceanic ridges


Geoinfo

The world’s longest landform feature is mid-oceanic ridges, which extend more than 64 000 km around the oceans.


ISBN 978 1 4202 3265 3


17

Ch

ap

ter 1

• Trenches—form the deepest parts of the oceans. They are the destructive edges of crustal plates where oceanic crust is subducting under continental crust, often causing earthquakes. Trenches are found parallel to land and seaward of volcanic island archipelagos e.g. Japan and Indonesia. The vast majority of trenches (18 out of 22) are located in the Pacific Ocean.

• Seamounts—submarine volcanoes that rise to more than 1000 m above the sea floor. Geologists estimate that there may be as many as 85 million seamounts. Where they rise above the surface, they form islands and atolls. Seamounts are created near mid-oceanic ridges or when oceanic crust moves over a hotspot, producing a chain of volcanoes e.g. the Hawaiian Islands.

Geoactivities 1.5


1 How significant are submarine landforms? 2 List two ways submarine landforms differ from

equivalent continental landscapes. 3 What is the difference between a continental shelf

and a continental slope? 4 Describe how mid-oceanic ridges and rift valleys

are formed 5 What are seamounts and how are they formed?

Inquiry and skills

6 Refer to 1.5.1.a List five landforms in the ocean.b Explain an abyssal plain and abyssal hill and

how they are formed. 7 Refer to 1.5.2 and explain a rapidly forming rift

valley. 8 Refer to 1.5.3.

a What is the name of the trench located near Australia?

b Name three ridges in the Indian Ocean. 9 Refer to 1.5.4.

a What is the name and size of the deepest ocean trench in the world?

b What is Challenger Deep?c What is the pressure at Challenger Deep?d Describe the type of technology used to

investigate the dark, deep trench.e Using Geocontext-Profiler on the internet, draw a

topographic profile of Challenger Deep. 10 Investigate the main threats to submarine

landscapes e.g. sea-floor mining, oil and gas drilling and commercial fishing. What can be done to protect these landscapes from over-exploitation?

1.5.4 Deepest ocean: Mariana Trench

[Insert aw 01030]


ISBN 978 1 4202 3265 318


1.6 Coastal landforms: erosionIn Australia, nine out of ten inhabitants live within 50 km of the coast, so coastal landforms are familiar features to most Australians. The majority of Australia’s World Heritage Sites are situated in coastal zones, such as the Great Barrier Reef, Lord Howe Island, Fraser Island and Shark Bay.

Coastal landscape diversityThe coast is a dynamic, narrow contact zone where the land and the sea interact. Coastal landforms are formed by two main processes:

• erosion e.g. cliffs, headlands and blowholes• deposition e.g. beaches, dunes and lagoons

Most of the erosion and deposition in coastal landscapes are caused by wind-generated waves. In addition, coastal landforms are sculptured by tides, currents and sea-level changes over time.

Australian coastal landscapesAustralia’s coastal area is 35 876 km with an additional 23 859 km of island coastlines. Most of the coastal

[Insert aw 01032]

1.6.1 Types of coastal landforms and water bodies in Australia

1.6.2 Coastal landforms


features we see today were formed over the last 6000 years, after the sea level reached its present level. However, there are variations in coastal landforms between places depending on the type of rocks, climate, weather and natural disasters.

• Rocks—softer rocks erode faster than harder rocks. Easily eroded rocks such as clay and shale tend to form beaches, whereas more resistant rocks to erosion such as limestone and chalk tend to form steep cliffs and headlands.


ISBN 978 1 4202 3265 3


19

Ch

ap

ter 1

• Climate—in tropical Australia (north of the Tropic of Capricorn), coastal landscapes are dominated by finer sediments (mud and silt), while in temperate Australia coarser sediments (rocks and sands) dominate.

• Weather—during storms or windy weather, high-energy destructive waves erode landforms. Low-energy waves tend to construct landforms by adding sand and material to the beach.

• Tsunamis and storm surges—erode landforms.

Erosion landformsCoastal erosion occurs when waves, tidal currents and winds wear down and remove sediments. Ultimately, erosion causes the coastline to retreat. The rate of erosion depends on wave and wind energy, which is related to climate. Wave energy and erosion is high during storms. Erosion produces distinctive coastal landforms, such as sea cliffs, rock platforms, arches, sea stacks, sea caves and blowholes.

On some coasts, such as in California, Papua New Guinea and the UK, the land has been uplifted and old coastal landforms below the ocean have been raised above the present-day ones. On coasts with rocks of variable resistance to erosion, different rates of erosion create geos (narrow, steep-sided eroded inlets) and coves. They also produce irregular coastlines, such as the bay and headland formations as found in NSW.

Geoactivities 1.6


1 Why is the coast a unique landscape environment? 2 Describe the main natural influences on coastal

landscapes. 3 How are coastal sediments in tropical and

temperate Australia different? 4 What is coastal erosion and what distinctive

landforms do they produce? 5 Explain how old coastal landforms are raised.

Inquiry and skills

6 Refer to 1.6.1. Why are depositional features divided into two types of coasts?

7 Refer to 1.6.2 and list the different landform features on the coast. Divide the features into erosion, deposition and transportation.

8 Refer to 1.6.3.a Explain how a line of weakness develops into an

arch.b Describe how the Twelve Apostles were formed.c Why will the Apostles all disappear in the future?

9 Refer to 1.6.4. a Explain how a wave notch is formed.b How is a wave notch the start of a retreating

cliff? 10 Investigate how a blowhole forms. Draw a diagram

to show this. 11 Using Google Earth, choose a section of the

Australian coastline and describe the erosion landforms.

12 Imagine you were one of the tourists stranded when the London Bridge Arch near Port Campbell collapsed. Recount your experience and the rescue.



1.6.4 A wave-cut notch and retreating rock platform

1.6.3 Erosion landform features


ISBN 978 1 4202 3265 320


1.7 Coastal landforms: depositionOver millions of years, sediments have accumulated along the Australian coast. A beach is an accumulation of loose sediment deposited by waves. Beaches constantly change due to the process of erosion, transportation and deposition. Along the NSW coast there are approximately 720 beaches. Most consist of sand, unlike the pebbles and rocks on beaches in the UK.

Coastal sedimentsSome coastal sediment comes from shell debris and the erosion of headlands, but most comes from rivers transporting eroded sediments from the land. Sediment ranges from fine clays and silts to sand, gravel, shingle and boulders. Waves, tides and longshore currents transport sediment. Deposition occurs when sediment supply is greater than its removal. Sediments move along coasts in two ways:

• landwards migration—forms sand dunes by wind erosion. There is a variety of dunes e.g. foredunes (closest to the surf) and parallel dunes (successive dunes)

• seawards transport—movement of sediments via ocean currents, often causing sand bars.

Barrier beaches and islandsThere are other depositional landforms that fringe low-lying coastal plains, for example:

• bars and barriers—off-shore deposits of sediment generally parallel to the coast

• spits—continuation of beaches that diverge from the coast, e.g. Noosa, Queensland

1.7.1 Coastal landforms caused by deposition

• tombolos—a spit joins an island e.g. Palm Beach, NSW

• lagoons—formed behind depositional features like spits and beaches, e.g. Dee Why Lagoon, NSW.

A barrier beach is a sand ridge that rises slightly above sea level and runs roughly parallel to the shore, separated by a lagoon. Barrier systems are never fixed; they change over time depending on the dynamic balance between sediment supply, wave energy and sea-level change. They serve as buffer zones to protect the coast from severe storms.

In the USA, barrier systems are under increasing pressure from human development, with more than 70% developed. Cities such as Miami and Atlantic City are located on barrier islands, and summer beach houses occupy many of the beaches.

Power of wavesWaves are the main agent of change to coastal landforms. The waves are generally formed by wind blowing over the ocean. The size of the wave depends on wind velocity, the distance the wind travels over the ocean, and the duration of time it blows. Tropical cyclones contribute to destructive or erosive waves battering the Australian shoreline.

When waves approach the shore, they break in different ways depending on the ocean topography:

• spilling—rise and break gently over a distance of several metres

• plunging—waves curl over the crest (popular with surfers)

• surging—waves run up beach slopes.



ISBN 978 1 4202 3265 3


21

Ch

ap

ter 1

As waves move from the sea to the beach it is called ‘swash’, and when waves run backwards out to sea it is called ‘backwash’. A constructive wave builds the beach when swash is more powerful than backwash, and a destructive wave erodes the beach when backwash is more powerful.

Sediment is also moved by rips and tides. Rips are fast flowing currents that are dangerous to swimmers, while tides move sediments in and out of bays and beaches twice a day. Waves move sediment along the beach by longshore drift—a process you might be familiar with from when you go for a swim and come out of the water quite a distance from your beach towel.

When beaches lose sand from longshore drift, groynes are built along the shoreline or new sand replenishes the area, which is called beach nourishment.

Geoinfo

The world’s largest and most continuous barrier system lies along the USA’s Atlantic Ocean and Gulf of Mexico coasts, extending over 4000 km.

A Formation of wavesB Destructive wavesC Constructive waves

1.7.2 Waves are important for dynamic landforms

[Insert aw 01039 – 41]

[Insert aw 01038]

1.7.3 Longshore drfit

Geoactivities 1.7


1 Why are coastal landforms and landscapes dynamic?

2 Where do coastal landscapes obtain their sediment?

3 How are sediments lost from coastal landscapes? 4 What are three different types of waves that

transport material? 5 How do rips and tides affect coastal landforms? 6 Explain how barrier beaches act as buffer zones.

Inquiry and skills

7 Refer to 1.7.1 and describe six coastal depositional landforms.

8 Refer to 1.7.2. Distinguish between swash and backwash on constructive and destructive waves.

9 Refer to 1.7.3. a Explain how longshore drift moves sediment

along beaches. b How can coastal communities reduce the loss of

sand? 10 In groups, research problems for Australians living

along the coast. Present solutions as a Prezi.


ISBN 978 1 4202 3265 322


1.8 Port Campbell coastlineOne of the most spectacular coastlines in Australia is located near Port Campbell in western Victoria. The soft limestone cliffs have been battered by strong winds and waves from the Southern Ocean for millions of years. This constant erosion has left rock stacks, caves, arches and blowholes. The Twelve Apostles (or stacks) are now down to eight, as high-energy waves have eroded the base of the stacks by 2 cm per year. This fragile coastline is protected within the Port Campbell National Park and managed by Parks Victoria.

London Bridge double arches in 1959 London Arch after collapse in 1990

1.8.2 From London Bridge to London Arch

1.8.1 Oblique aerial photograph of the Port Campbell coastline

Mixed views aired over Great Ocean Road rezoningResidents along the Great Ocean Road are divided over the Victorian Government’s decision to rezone tracts of land for tourism development. Mayor Chris O’Connor says the creation of new tourist facilities will be a boon for the economy.

“We only have about 200 000 overnight stays but we have 2.6 million people come through and we just don’t thank that is good enough,” he said.

However, Marion Manifold, from the Port Campbell Community Group, says the Minister has ignored residents’ concerns. She says development will destroy the untouched landscape which draws people to the region. “You just don’t do this because it is going to destroy the product that the people come here for,” she said.

www.abc.net.au

[Insert aw 01045]

[Insert aw 01046] [Insert aw 01046.1]

A

B

C

D

E


ISBN 978 1 4202 3265 3


23

Ch

ap

ter 1

Geoactivities 1.8


1 Where is Port Campbell located? 2 What coastal landforms are found in this location?

Inquiry and skills

3 Refer to the article.a What are the different views on developing

Port Campbell?b Discuss the impacts of tourists on the natural

environment. c Suggest five management strategies to reduce the

impacts of tourism. 4 Refer to 1.8.1.

a Label the coastal features A to E.b What time of the day was this photograph taken? c Draw and label a form line diagram of the coastline

showing erosion, transportation and deposition processes.

5 Refer to 1.8.2. a Describe the processes that led to the collapse of

one of the arches in 1990.b Draw and label a sketch of what could occur to

these landforms in next 1000 years.

6 Refer to 1.8.3. a What are the advantages and disadvantages of

this map? b Using Google Earth find the latitude and longitude

of the Twelve Apostles.c What are the GR of the Blowhole and Picnic Area?d What are the AR of the Haystack and Mutton Bird

Island?e How was sand formed in AR8218?f Explain why this area has more erosion features

than deposition features.g What is the name of the ocean where Twelve

Apostles are located?h Draw a cross section from A to B.

7 Imagine you were to visit this location. Research the attractions you would visit and tourist facilities in the area.

8 Design a tour along the Great Ocean Road. Draw an annotated map of the tour including sketches of the landforms along the route. Describe how two of the landforms have been formed.

1.8.3 Topographic Map of Port Campbell National Park

[Insert aw 01048]


ISBN 978 1 4202 3265 324


1.9 Coral reefs: biological landscapes

Tiny animals called coral polyps are responsible for creating the world’s largest biological landscapes—extensive coral reefs in tropical oceans. Coral polyps live in colonies and build external skeletons of calcium carbonate (limestone) that over time become coral landforms. Coral reefs occupy only 0.17% of the ocean floor, but they provide a habitat for more than 25% of all marine species.

Corals have specific environmental requirements for growth. They need sunlight and thrive best in waters from 2–30 m deep. Corals also need clear water and do not survive in muddy waters near rivers. Coral polyps need to be protected from the sediment and nutrients in agricultural and urban run-off. Worldwide, coral reefs are under threat from a variety of human activities, global warming and rising sea levels. There are four main types of coral reefs.

[Insert aw 01053]

1.9.2 Aerial image of Bora Bora, French Polynesia, showing the intermediate stage in the evolution of an atoll

1.9.1 Cross section of four types of reefs

Fringing reefs and platform reefsFringing reefs form a narrow band between 0.5 and 1 km wide surrounding islands and continents. Ningaloo Reef and continental islands such as the Whitsundays have Australia’s best fringing reefs.



ISBN 978 1 4202 3265 3


25

Ch

ap

ter 1

Platform reefs are isolated, oval patches located on continental shelves. They are 3–10 km long and often enclose a lagoon. They formed when coral polyps colonised the submarine hills of drowned coastlines as sea levels rose after the last ice age, about 10–12 000 years ago. Australia’s Coral Sea Islands Territory has many platform reefs. Some have coral cays (sandy reef islands) and, if these are stable, they may be vegetated and colonised with birds and small animals.

AtollsAtolls are circular reefs that rise from deep seas and enclose a shallow lagoon. Most are located in the tropical Indo-Pacific region. In 1842 Charles Darwin proposed a theory that atolls keep growing as volcanic islands gradually sink. Core drilling has confirmed that atolls do form on subsiding volcanic islands. Coral on some atolls has grown up to 1400 m thick over a 40–50 million year period to keep pace with the sinking land. As the reef erodes, calcium-rich sand and shell fragments are deposited in the lagoon.

Barrier reefsBarrier reefs form long landforms separated from the mainland by a lagoon that can be wider than 20 km. Australia’s Great Barrier Reef (GBR) is the world’s most famous example. It comprises 2900 individual reefs, which vary greatly in shape and size. The GBR is about 15 million years old in the north (where it is 1–2 km thick) and two million years old in the south (where it is about 120 m thick).

The GBR has not always been in its present form. During the last ice age, the sea level dropped and exposed the coral landforms to weathering and erosion. Rivers cut channels through the reef limestone and the limestone dissolved in some places, forming solution holes. When the sea levels rose, corals recolonised the eroded surfaces to form a thin veneer over the relic surface.

The GBR was listed as a World Heritage Area in 1981. The GBR Marine Park Authority protects and manages the marine park and the World Heritage Area.

Geoinfo

The Great Barrier Reef is the world’s largest living landform, covering about 270 000 km2 and extending some 2300 km along Queensland’s coast.


1.9.3 How the Great Barrier Reef evolved with sea-level change

Geoactivities 1.9


1 How do coral polyps build landforms? 2 Outline the physical requirements of coral polyps. 3 How are atolls formed?

Inquiry and skills

4 Refer to 1.9.1 and describe the different types of coral landforms.

5 Refer to 1.9.3 and explain the changes to the Great Barrier Reef during and after the last ice age.

6 Research what is being done globally to protect coral reefs. Outline the management strategies used by the GBR Marine Park Authority.

7 Identify the problems facing coral reefs. Create a PowerPoint slide to explain the solutions to these problems.

8 Discuss this statement: Coral reefs are like the modern canary in the coal mine of global warming.

9 Describe the connections between terrestrial landscapes and coral reefs.

10 Research the problems of developing coal export harbour facilities inside the Great Barrier Reef. Present your findings as an oral report.


ISBN 978 1 4202 3265 326


1.10 High, low and flat landformsMountains, hills, plateaus and plains represent the highest, lowest and flattest landforms. Together they occupy most of Earth’s terrestrial and oceanic land surfaces.

MountainsTectonic activity in Earth’s crust over millions of years has created the planet’s highest landforms—

mountains. In geological time, mountains are temporary because they are constantly being worn down by weathering and erosion. However, some ‘young’ mountains on the margins of tectonic plates (e.g. the Himalayas and some volcanoes) are still being created. Mountains exist on all continents—some are islands and others are located on ocean floors (seamounts).

1.10.1 Different landforms

Landforms Features

Mountains • natural elevated surfaces greater than 600 m• have a large mass, steep sides and valleys, jagged profile and

rugged terrain• usually found together in ranges or chains, except for isolated

volcanoes• older mountains have a lower elevation and are more worn down• cover about 25% of Earth’s land surface

Examples

• Ranges: Himalayas, Alps, Rockies, Andes, Urals, Caucasus, Atlas Mountains, Transantarctic, Australian Alps, Southern Alps (NZ), Drakensberg (South Africa)

• Mountains: Mount Fuji (Japan), Ben Nevis (UK)

Plateaus Features

• large, relatively level areas rising more than 450 m above the surroundings

• have at least one steep, cliff-like side• also called flat-topped mountains or tablelands• formed by tectonic uplift or extensive lava flows• can also have extensive elevated plains with gentle relief• cover about 45% of Earth’s land surface

Examples

• Deccan Plateau (India)—lava flow• Western Plateau (Australia)—covers two-thirds of the continent

and is more than 500 million years old• Tibetan Plateau (SW China)—world’s largest and most extensive

Plains Features

• low-lying landscapes that are flat or gently undulating with no steep sides

• formed primarily by erosion and the deposition of sediment (alluvial, glacial or aeolian [wind-blown])

• interior or continental plains are often bordered by mountains• occupy more than 50% of the interior of most continents• coastal plains cover less than 1% of Earth’s land surface• abyssal plains are the flattest of all landscapes and cover more

than 50% of the land surface of the oceans

Examples

• West Siberian Plain (Asia)• Great Plains (North America)

[Insert aw 01055.1]

Mt Everest (8848 m) is the world’s highest continental mountain

Deloraine, Tasmania

West Siberian Plain

[Insert aw 01055.2]

[Insert aw 01055.3]


ISBN 978 1 4202 3265 3


27

Ch

ap

ter 1

Alternative mountain names include ben (Scottish), berg (German/South African), alp (Indo-European for white), sierra (Spanish for saw) and cordillera (Spanish for little cord). A cordillera is an extensive chain of mountain ranges. The term is usually applied to the many ranges of the Andes in South America.

Hills, plateaus and plains Mountains are significant landforms that distinguish them from other major landforms.

• Plateaus tend to have flat tops and steep sides, whereas mountains have small summits, a more irregular skyline and gentler slopes.

• Hills have similar features to a mountain but are under 600 m.

• Plains are generally flat to undulating, and are not elevated.

The Blue Mountains in Australia and the Catskill Mountains in the USA are not in fact mountains—they are dissected plateaus, eroded by rivers. If you look at their skylines they are fairly even, and if you stand on the top of the Blue Mountains you will see all the other tops are almost the same height. The top represents the plain before uplift, which was then eroded. Isolated portions of plateau are known as mesas.

Valleys of deathBetween mountains and plateaus there are valleys. A deep river valley is sometimes called a canyon or gorge. River valleys tend to be V-shaped, compared

to glacial valleys, which are U-shaped. One famous valley is Death Valley, in the Mojave Desert, California. It is the lowest and driest area in North America, with average summer temperatures exceeding 37 °C. The valley is home to the Native American Timbisha tribe, who have inhabited the valley for over 1000 years. This landform has been designated a National Park.

If you look at the first page of this chapter, there is a photograph of the Grand Canyon, which is a steep-sided canyon carved by the Colorado River. For thousands of years, the area has been continuously inhabited by Native Americans and was considered a holy site by the Pueblo people. The Grand Canyon is a National Park and a popular tourist site.

[Insert aw 01056] not very clear, re-draw?

1.10.2 World’s largest mountains by continent/region

1.10.3 Features of mountain landforms


Geoactivities 1.10


1 Why are mountains seen as temporary landforms in geological time?

2 What is the difference between a mountain, a hill and a plateau?

3 Explain why the Blue Mountains are actually dissected plateaus.

4 How are plains formed and where are they found?

Inquiry and skills

5 Refer to 1.10.1 and 1.10.2. Use geographical terms to describe the features of Mt Everest and its surrounding valleys.

6 Refer to 1.10.2. Prepare a report on the reasons why mountains on mainland Australia are small.

7 Refer to 1.10.3. Present a diagrammatic cluster map illustrating terms such as summit, ridge, divide, scree and snowline.

8 Create a fact file on Mt Ben, Heard Island. Present as a tagxedo.


ISBN 978 1 4202 3265 328


1.11 Types of mountain landformsThere are three main types of mountains: fold, fault-block and volcanoes. Each is named after the tectonic processes that created them. Mountain-building processes proceed gradually, except for volcanic eruptions, which may be sudden and spectacular. The processes of mountain formation are explained in chapter 3.

Fold mountains: collisions zonesThe world’s tallest mountains and most extensive mountain ranges are all fold mountains. Young fold mountains form in unstable zones where converging (destructive) tectonic plates in Earth’s crust collide. The plates bend the bedrock in a similar way to a rug that folds when it is pushed from both sides. Some young fold mountains are located on the edges of tectonic plates. Old fold mountains, such as the MacDonnell Ranges in the Northern Territory, are located in stable zones in the interior of continents.

Fault-block mountains: fracture zonesIf fold mountains bend Earth’s crust, then fault-block mountains fracture it. Enormous pressure is exerted on Earth’s crust along weaknesses called fault lines. The bedrock stretches until it eventually releases. This produces earthquakes, displacement of the surrounding land and sometimes volcanic

[Insert aw 01062 to be redrawn?]

1.11.1 World map of young fold mountains, active volcanoes and earthquake zones corresponding to edges of tectonic plates

[Insert aw 01064]

1.11.2 Folding: aerial view of the MacDonnell Ranges, NT, showing the eroded remnants ancient fold mountains that were once higher than the Himalayas

activity. Fault-block mountains are usually found in the interior of continents at constructive (divergent) plate margins. The Sierra Nevada mountain range is an example of fault-block mountains. The East African Rift Zone is a famous fault-block mountain system centred on a divergent plate boundary, which is in the process of breaking up the African Plate.


ISBN 978 1 4202 3265 3


29

Ch

ap

ter 1

Volcanoes: hot zonesVolcanoes form when magma from deep inside Earth erupts at the surface of the crust, either on land or under the sea. Volcanic mountains are found at the edges of tectonic plates and over hot spots in Earth’s crust. Earth has about 500 active volcanoes, but many more are dormant, meaning they have not erupted in a long time. Extinct volcanoes are unlikely to erupt again. Volcanoes also create dome mountains, when magma accumulates underground like a mushroom and uplifts the surrounding land.

Geoinfo

Young mountains have deep ‘roots’ because Earth’s crust is very thick under them. As mountains wear down, the roots move upwards in a process called isostasy.

1.11.3 The East African Rift Valley is in the process of splitting the African Plate into two


[Insert aw 01066]

1.11.4 Aerial pic of San Andreas Fault, California, USA. The world’s most famous transform fault, where mountains form on either side of two tectonic plates that are sliding past each other

Geoactivities 1.11


1 What are the three main types of mountains? 2 Why are earthquakes, displacement of the

surrounding land and sometimes volcanic activity common in fault zones?

3 Using labelled diagrams, explain the differences between active, dormant and extinct volcanoes.

4 What are dome mountains and how are they formed?

Inquiry and skills 5 Refer to 1.11.1. Describe the location of fold

mountains, volcanoes and earthquakes. 6 Refer to 1.11.3 and an atlas. Name the mountains

associated with the East African Rift Valley. What will eventually happen to this landform feature?

7 In pairs create a PMI for living on an active fault line. As a class compare your PMIs then create a class PMI.

8 Discuss this statement: Civilization exists by geologic consent, subject to change without notice (Will Durant, US historian, 1885–1981).


ISBN 978 1 4202 3265 330


1.12 Valley glacial landscapes and landforms

Glaciers are dynamic, large, moving bodies of compacted ice that exist for long periods of time. Glaciation is the process whereby glaciers create distinctive landscapes and landforms through their enormous erosional power, and their ability to transport and deposit sediments as they move slowly downhill under gravity and their own weight. There are two main types of glacial landscapes: valley and continental.

Ice ages: the big freezeEarth has experienced multiple ice ages over geological time, some of which lasted millions of years. In the last ice age, which ended around 10 000 years ago, glaciers covered up to a third of Earth’s land surface, transforming landscapes. Unsurprisingly, many landscapes today have relic glacial landforms—a legacy of past ice ages.

[Insert aw 01068 and 01069]

1.12.1 Features of a mountain landscape during (left) and after (right) glaciation

[Insert aw 01070]

1.12.2 Aerial view of valley glaciers flowing from Greenland ice sheet to the coast


ISBN 978 1 4202 3265 3


31

Ch

ap

ter 1

Rivers of iceValley glaciers currently exist in high mountainous regions on most continents except Australia. Alpine glaciers are born high above the snow line in the headwaters of tributary streams. As they progress down the valley, they become valley glaciers, which scour the valley sides and transport sediment to their snout where it is deposited. Moraine is the term for the rocks and sediment deposited by a glacier. Valley glaciers completely transform narrow river valleys into broad glacial valleys with distinctive features that are evident long after the glaciation has finished. Global warming has produced rapid melting of most of the world’s valley glaciers. According to the United Nations Environmental Programme, if all Earth’s valley glaciers melt, sea levels would rise 15–37 cm.

Geoactivities 1.12


1 What are glaciers and what is glaciation? 2 Why do many landscapes today have relic glacial

landforms? 3 What is the difference between an alpine and a

valley glacier?

Inquiry and skills

4 Refer to 1.12.1.a Describe what happens during and after valley

glaciation.b Explain the origins of the various types of

moraine.c What is the difference between the zone of

accumulation and the zone of ablation? 5 Refer to 1.12.4 and explain how fjords form. 6 In pairs present an interview with someone who

has experienced a moving glacier. 7 Using Google Images, copy several images of

valley glaciers from different part of the world and label their landform features.

8 Refer to valley glacier photos on the BBC website (see Geolinks). Describe the changes to valley glaciers shown in the photos. How can valley glacial landscapes be protected?

9 What is the Third Pole? What problems are forecast if the glaciers melt?

[Insert aw 01071]

[Insert aw 01073]

1.12.3 Aerial view of Barnard Glacier, Alaska, USA showing various types of moraine

1.12.4 This fjord at Geiraner, Norway, is a flooded former glacial valley. Fjords are located on the western coasts of glaciated lands such as Norway and New Zealand

Geoinfo

• Glaciers cover roughly 10% of Earth’s land surface. • Glaciers cover 510 000–540 000 km2 and a volume

of 50 000–130 000 km3.


ISBN 978 1 4202 3265 332


1.13 Glacial topographic mapThe Southern Alps of New Zealand’s South Island contain excellent examples of valley glacial landscapes. The map extract shows the Aoraki/Mt Cook alpine

[Insert aw 01075 around here - Insert northings on the left side of the topographic map extract starting at 28 at the bottom and going up to the top dark line which is 40. Insert the eastings at the bottom of the page starting at 88 on the left side and ending with

98 on the right side.]

1.14.2 Topographic map extract showing part of the Aoraki/Mt Cook alpine area, New Zealand

area—a World Heritage Site on the South Island. The map clearly shows that glaciers are retreating as a result of global warming.


ISBN 978 1 4202 3265 3


33

Ch

ap

ter 1

Geoactivities 1.13


1 What is glaciation?

Inquiry and skills

2 Refer 1.13.2. a Identify the physical landforms located at the

following area references: AR9389, AR9138, AR9132.

b Identify the physical landforms located at the following grid references: GR915337, GR935337, GR961314.

c Estimate the length of Darwin Glacier AR 9337 and the large moraine-dammed lake at the end of Murchison Glacier AR 9329.

d What is the straight line distance between Onslow Hut (GR 927286) and Kalman Hut (GR 966398)?

e Compare the widths of the Tasman and Murchison glaciers.

f Draw a cross-section across the Tasman Glacier along northing 37, including the mountains on either side.

g Research the difference between moraine, moraine walls and scree. Using the map, describe the general location of these three landform features.

5 Imagine that you walking up the Tasman and Murchison glaciers. Describe the landform features that you would see on your walks. List the landform evidence that shows that both glaciers are retreating.

[Insert aw 01074]

1.14.1 Upper Tasman Glacier and Malte Brun Range, Aoraki/Mt Cook National Park, New Zealand

Geoinfo

The 27 km long Tasman Glacier is New Zealand’s longest glacier. It is retreating at up to 800 m a year and will eventually disappear if current melting rates continue.

[include key]


ISBN 978 1 4202 3265 334


1.14 Ice sheet glacial landscapes and landforms

Unlike valley glaciers, ice sheets (also called ice caps) are masses of land ice covering more than 50 000 km2. They not confined to mountains, but extend over vast areas of land, often burying mountains, lakes and other landforms. Ice sheets flow slowly downhill (like glaciers, under gravity and their own weight), drastically changing the landscape and producing distinctive landforms.

Ice sheets and ice ages During ice ages, ice sheets expand from polar regions to cover as much as a third of Earth’s land surface. Some ice sheets have been up to 4 km thick. The successive advance and retreat of ice sheets during and after ice ages has left a legacy of glacial landforms on many of Earth’s landscapes.


1.14.1 Area of the northern hemisphere affected by continental glaciation during the last ice age 10 000 years ago

1.14.2 Features of a landscape during and after continental glaciation


Eskers in North Dakota, USA

Polygons and kettle lakes, Arctic National Wildlife Refuge, Alaska, USA

[Insert aw 01078]

[Insert aw 01079]


ISBN 978 1 4202 3265 3


35

Ch

ap

ter 1

1.14.3 Lake Missoula and the Scablands 18 000 years ago


Ice sheet erosion and deposition landformsMany landscapes today still have relic landforms created by ice sheets during ice ages. These landforms are scattered over large areas of Europe, Asia and North America, corresponding to the extent of the glaciated areas during the last ice age (see 1.14.1). The Great Lakes of North America and the large bays connected to them are glacial erosional landforms. Ice sheets have also given Canada thin soils and more lakes than any other country.

Other impacts of ice sheetsIce sheets have had three other impacts on Earth’s landscapes: sea level changes, rebounding landforms and mega floods. At the peak of the last ice age, around 20 000 years ago, sea levels dropped 120 m below their current level because glaciers stored vast amounts of water on land. As ice sheets retreated, rising sea levels created rias (drowned river valleys) and fjords (drowned glacial valleys). The compressed landforms under the previous ice sheets slowly rebounded in places in a process called isostasy. This is still happening in the Scandinavian Peninsula.

Another impact resulting from glaciation occurred when ice sheets dammed valleys, creating massive glacial lakes. As the ice melted, the dams failed and mega floods caused enormous landform change in only a few weeks. For example, glacial Lake Missoula in the northern USA released around 2100 km3 in major flood episodes, about 40 times from 100 000 years ago until about 10 000 years ago. This created the famous Scablands landscape, which has an area of around 5200 km2.

Geoinfo

About 15 000 years ago, Lake Bonneville in Utah, USA, broke through a moraine dam and released around 4200 km3 (almost 7.5 million times the volume of Sydney Harbour!) in one monstrous flood.

Geoactivities 1.14


1 What is the difference between valley glaciers and ice sheets?

2 Explain why ice sheets have left a legacy on many landscapes today.

3 Describe the relic glacial landforms of North America.

4 Explain how changing sea levels and post-ice age catastrophic flood episodes during ice ages have affected Earth’s landscapes.

Inquiry and skills

5 Refer to 1.14.1 and an atlas. In which European countries would you expect to find relic glacial landforms?

6 Refer to 1.14.2. Describe the main landforms created by ice sheets.

7 Write a brief report on isostasy and catastrophic flooding resulting from ice ages, mentioning examples.

8 Research the relic glacial landforms of Australia. Where are they located and how are they protected? Can you identify the different types of glacial landform?


ISBN 978 1 4202 3265 336


1.15 Ice sheet landscapes of Greenland and Antarctica

The twin ice sheets (ice caps) of Greenland and Antarctica, located at the North Pole and South Pole respectively, contain 99% of Earth’s freshwater. As the world’s largest ice sheets, they exert a powerful influence on climate. However, their existence is threatened by global warming.

World’s last great ice sheetsNear the coasts of Greenland and Antarctica, ice sheets sometimes squeeze through narrow gaps in mountains acting as relatively fast-moving glaciers. In Antarctica, they flow out as ice shelves and ice tongues that project over the sea. Icebergs eventually break off the edges in the ablation zone.

The Greenland Ice Sheet contains around 12% of the world’s ice and the Antarctic Ice Sheet contains about 87%. The ice sheets on the island of


1.16.1 Location of Greenland and Antarctica

[Insert aw 01084]

1.15.2 Ice sheets in Greenland and Antarctica

Greenland and the continent of Antarctica are the last remnants of the last ice age. The two ice sheets have different characteristics, relating to the depth of underlying bedrock and the thickness of the ice.


ISBN 978 1 4202 3265 3


37

Ch

ap

ter 1

Global warming threat to ice sheetsThe impact of global warming on Greenland and Antarctica has raised fears that the melting ice sheets will trigger sea level increases that will inundate low-lying countries. According to the United Nations Environmental Programme, if the Greenland and Antarctic ice sheets melt, sea levels would rise 7.3 m and 56.6 m respectively. The mass of the Greenland Ice Sheet is declining rapidly as glacial melting increases near the coast. In Antarctica, the Antarctic Peninsula has warmed about 2.5 °C since 1950. A large part of the West Antarctic Ice Sheet is losing mass, but the situation in East Antarctica is relatively stable.

Geoactivities 1.15


1 Describe the significance of Antarctica and Greenland landforms and landscapes.

2 What are ice sheets? How are they connected to ice shelves and ice tongues?

3 Explain how global warming is threatening the Greenland and Antarctic ice sheets.

4 What impacts will global warming have on sea levels and low-lying countries?

1.15.3 Comparing ice sheets on Greenland and Antarctica


[Insert aw 01088]

1.15.4 Satellite image of Jakobshavn Isbrae and ice fjord, Greenland, showing the calving ice front from 1851–2013

Inquiry and skills

5 Refer to 1.15.2 and 1.15.3. Describe the differences between the Greenland and Antarctic ice sheets.

6 Research the cryosphere (ice sphere). Prepare a PowerPoint presentation on the glacial landscapes of the cryosphere and the impacts of global warming on them.

Geoinfo

Antarctica is the world’s largest glacial landscape. The Antarctic Ice Sheet feeds many ice shelves, ice tongues and thousands of glaciers, including the world’s longest—Lambert Glacier.


ISBN 978 1 4202 3265 338


1.16 Karst processes, landforms and landscapes

The awe-inspiring, beautiful colours and mysterious formations in the Jenolan Caves—nestled in the Blue Mountains World Heritage Area—make the caves a popular site for geographers and tourists alike. ‘Legends, Mysteries and Ghosts’ is a favoured tour.

Indigenous Peoples tell of the Jenolan Caves being created in the Dreamtime when Gurangatch, part eel and fish, engaged in a deadly struggle with Mirragan, a native quoll. Gurangatch rested and lay regaining his strength where Blue Lake is now located.

Karst unique landformsHundreds of magnificent karst formations are scattered across the world, for instance the Nullarbor Region of Australia, Shan Plateau of China, Atlas Mountains of northern Africa and Belo Horizonte of Brazil. The Phong Nha-Ke Bang caves in Vietnam and Laos comprise 300 caves extending over a vast area of 70 km. The area is a national park and a World Heritage Site.

Approximately 10% of the Earth’s surface is occupied by karst landscapes, and 24% of the world’s population depends on karst springs for water supplies. Karst landforms are shaped by surface or ground water, which chemically dissolves the rocks. Although mostly associated with carbonate rocks such as limestone and dolomite, other soluble rocks

[Insert aw 01091]

1.16.1 Jenolan Caves attracts tourists for its aesthetic natural beauty

1.16.2 Karst regions of the world


such as gypsum and rock salt can be sculpted into karst landscapes. This geological process occurs over millions of years, resulting in unusual landforms that vary from rolling hills dotted with sinkholes (New Zealand) or jagged hills (Guilin, China), to islets in Ha Long Bay, Vietnam.

Karst process The process of karst formation is referred to as ‘the carbon dioxide cascade’. Precipitation—rain or

snow—soaks into the soil, and the water becomes slightly acidic after chemically reacting with carbon dioxide in the atmosphere and soil. Precipitation infiltrates downward through the soil and through cracks in the rocks. The acid dissolves carbonate rocks along the cracks, forming underground caves.


ISBN 978 1 4202 3265 3


39

Ch

ap

ter 1

The karst process results in formations beneath and above the Earth’s surface. Above-ground characteristics include:

• sinkholes, dolines or cenotes• disappearing streams and

reappearing springs• isolated hills composed of

limestone, marble or dolomite, surrounded by alluvial plains e.g. Viñales Valley in Cuba

• limited surface water, as rivers or lakes drain underground rather than flow along the surface of the ground.

Below the ground, underground drainage systems form, including karst aquifers and caves. In caves, a variety of features called speleothems appear, such as stalactites and stalagmites, which are formed by the slow deposition of calcium carbonate and other dissolved minerals.

Karst regions with caves, natural bridges and travertine pools (made from limestone deposited by mineral springs) attract tourists, who enjoy exploring caverns and diving in submarine caves. However, karst landforms support unique ecosystems—karst ecosystems in Croatia host 3500 species of flora plus over 300 species of resident birds, mammals, reptiles, amphibians and freshwater fish. These fragile ecosystems are vulnerable to anthropogenic (human-caused) and climatic stresses.

Geoactivities 1.16


1 Explain two different views of how karst caves were created.

2 Why are karst formations important to humans? 3 List four karst formations. 4 What is meant by the ‘carbon dioxide cascade’? 5 List three karst landforms observed above the

ground. 6 Discuss why karst tourism is popular and why karst

regions should be protected.

Inquiry and skills

7 Refer to 1.16.1 and 1.16.4. Compare the different karst landforms above and below ground.

8 Refer to 1.16.2. Explain how karst formations are located in most countries. Provide examples.

9 Refer to 1.16.3.a Describe the karst process from precipitation to

an underground spring.b What features on land indicate karst processes

are operating underground? 10 Kentucky, USA, is referred to as ‘karst country’.

Research the type and extent of its karst formations and its impacts on the landscape and people.

[Insert aw 01092]

1.16.3 Jagged hills in Guilin, China


1.16.4 Karst formations: caves, disappearing streams, springs and underground rivers

Geoinfo

The world’s largest karst-protected area is in Honduras, covering 2400 km2 within the Patuca National Park and Tawahka Anthropological Reserve.


ISBN 978 1 4202 3265 340


1.17 Sinking world: sinkholesImagine that one day you are playing soccer in the backyard and the next day there is a gaping hole there with your house precariously hanging over the edge. This alarming scenario has been known to happen in places like Florida where the ground contains a lot of limestone.

For centuries, depressions in the ground formed by karst processes were used as disposal sites. The Maya on the Yucatan Peninsula Mexico regarded them as sacrificial sites and storage areas. Cave diving in sinkholes is a popular recreational activity. The Blue Hole—off the coast of Belize—is the world’s largest sinkhole.

SinkholesSinkholes are depressions or holes on land or in the ocean. They can be shallow or deep and small or large, ranging from 1 m to a massive 300 m in both diameter and depth. The largest sinkhole is the Qattara Depression near Cairo, Egypt. It is 80 km long and 120 km wide.

Sinkholes are caused by the dissolution of limestone, dolomite, marble or other carbonate rocks. There are two main types:

• solution sinkholes—formed slowly when bedrock dissolves, creating a bowl-shaped depression

• collapse sinkholes—shallow caves formed by dissolution of the bedrock suddenly collapse.

[Insert aw 01097]

1.17.1 The Blue Hole off Belize. Sinkholes that form in coral reefs and islands collapse to enormous depths

Sinkholes can cause death and loss of property. Shallow sinkholes frequently fill with water to form lakes or ponds, such as the Winter Park Florida Sinkhole. The Sinkhole Plain in central Kentucky has 5.4 sinkholes per square kilometre over a 153km2 area, while Florida has 8 sinkholes per square kilometre over 427km2. When several sinkholes join, they form a larger hole known as a poljen.

[Insert aw 01094]

1.17.2 How sinkholes form in karst landscapes


ISBN 978 1 4202 3265 3


41

Ch

ap

ter 1

Human activitiesSinkholes are formed by karst processes. Geologists do not consider large holes caused by humans to be sinkholes. In Berezniki, Russia, a huge 200 m deep, 80 m long and 40 m wide hole was created by underground mining. However, humans have contributed to the number and size of karst-formed sinkholes in urban areas with broken water pipes and sewer systems plus the over-extraction of groundwater.

In parts of the world, such as China and southeast USA, people live on top of karst landforms. As a result, some areas have experienced subsiding ground, contaminated groundwater and destruction of cave ecosystems. Signs of sinkholes include cracks on buildings and footpaths, sediment in tap water, and depressions in the ground. To repair sinkholes, building foundations are anchored to bedrock and cement pumped into caverns to reduce the risk of collapsing.

Karst groundwater is a natural resource that feeds waterways and is a source of drinking water. The quality of the groundwater depends on how people use the land and how they protect the quality of groundwater recharge. An old saying is ‘whatever goes up must come down’, but in karst areas, whatever goes down comes up—through a cave, a spring or a well.

Geoactivities 1.17


1 How have humans used sinkholes? 2 Describe how sinkholes vary in size, number and

distribution across landscapes. 3 The media called the Berezniki hole a ‘sinkhole’, but

geologists would say that was incorrect. Explain this statement.

4 Discuss how humans have contributed to the increase in the number of sinkholes.

5 Prepare a list of warning signs that an area could contain a potential sinkhole. Present as a report.

Inquiry and skills

6 Refer to 1.17.1. Describe the process of the formation for this sinkhole, and its problems and advantages.

7 Refer to 1.17.2.a What is a sinkhole?b Describe the formation of a collapse sinkholes.c How can sinkholes be repaired and reduced in

number? 8 Refer to 1.17.3 and imagine this was your property.

What would you do? 9 Refer to 1.17.4.

a How can you distinguish between a depression in the ground and a hill?

b What happens when a river meets a sinkhole? 10 Design a tour called ‘See the world’s sinkholes’.

Include an annotated travel map with latitude and longitude as well as the causes and impacts of the sinkhole on the landscape and surrounding communities. Present as a PowerPoint.

11 Explain why an understanding of karst development and the location of karst features is important for town planners.1.17.3 Aerial view of sinkholes pock-marking the limestone

rock in a karst landscape west of Timaru, Pareora, New Zealand


1.17.4 Topographic map section—the contour lines with hatch marks are depressions, indicating the land is lower than the surrounding area and have been subject to karst processes. It is a way of distinguishing a depression from a hill

Geoinfo

• The name cenote derives from a Mayan word meaning abysmal and deep.

• Winter Park Florida Sinkhole, which formed in 2001, is now a park.

[Insert aw 01095]


ISBN 978 1 4202 3265 342


1.18 Going underground: bat cavesCaves made from karst processes are valued as places for recreation and shelter. The Blue Grotto on the island of Capri, Italy, is a limestone sea cave hollowed out by wave action. It attracts more than 250 000 visitors a year. Mammoth Cave National Park in Kentucky, USA, contains 640 km of passageways and is the largest cave system in the world. It is a World Heritage Site and an international Biosphere Reserve.

Caves form a tiny part of most karst landscapes but support unique ecosystems that have adapted to the dark but stable environments. Karst caves are home to glow worms (e.g. Mole Creek Karst National Park, Tasmania) and to hundreds of species of bats around the world.

Speleothems: cave depositsThe breathtaking beauty and mystery of karst caves makes recreational caving a popular activity. Speleological Societies visit caves to view the mineral deposits called speleothems.

Speleothems are formed by the slow deposition of calcium carbonate and other dissolved minerals when water seeps through cracks in a cave’s bedrock. Over thousands of years the accumulation of these deposits form soda straws, stalactites, stalagmites, columns, shawls and flowstones, as seen in the Jenolan Caves.

Scientists seek answers to past climates in karst caves, as the growth of speleothems is an indicator of the quantity of groundwater dripping into the


1.18.1 Formation of caves

1.18.2 Cave formations: dripstones

Straws are thin-walled hollow formations resembling drinking straws

Stalactites grow downwards from the cave roof. Nearly all stalactites start their life as straws

Stalagmites grow upwards from the cave floor, formed by drops of water from the roof or stalactites overhead

Columns or pillars develop when stalactites meet stalagmites

[Insert aw 01103.1] [Insert aw 01103.2] [Insert aw 01103.3] [Insert aw 01103.4]


ISBN 978 1 4202 3265 3


43

Ch

ap

ter 1

cave. Little growth may indicate a drought, while rapid growth means heavy precipitation. When the outside of a speleothem becomes dirty it generally indicates growth has stopped; if they are shiny, smooth and wet they are still growing.

Karst in Australia: Nullarbor PlainAustralia’s karsts landforms cover 4% of the continent, but could be underestimated due to incomplete geological mapping. The South Australian Limestone Coast contains the Naracoorte Caves—Australia’s largest source of fossils and a World Heritage Site. Notable tourist locations include:

• Nullarbor National Park—the vast Nullarbor Plain is the world’s largest limestone karst landscape. It covers an area of 270 000 km2, extending 2000 km between Norseman and Ceduna. The Nullarbor National Park and Regional Reserve aims to protect the world’s largest semi-arid cave karst system. Over 250 caves are recorded with the ocean flowing into some caves and creating blowholes, e.g. the Murrawjini Caves.

• Nuytsland Nature Reserve— located in southeast Western Australia, the reserve extends along the coast for 500 km. Within the reserve is Twilight Cove—famous for its 70 m limestone cliffs that overlook the Great Australian Bight.

Increasing tourism has resulted in environmental damage to caves. Project Underground aims to build responsible attitudes toward karst and cave resources and their management. WildCountry—an initiative of the Wilderness Society—aims to involve indigenous custodians in managing karst landforms and their unique habitats.

Geoactivities 1.18


1 Name three underground caves. 2 Why are karst caves important? 3 What are speleothems?

Inquiry and skills

4 Describe the importance of the Nullarbor Plain karst system.

5 Research how the Nullarbor karst formations sustained and allowed for the expansion of Indigenous Australians. Present as a report.

6 Refer to 1.18.1 and describe how caves form over time.

7 Refer to 1.18.2. a What is the difference between stalactites and

stalagmites?b Describe how a column is formed.

8 Refer to 1.18.3 and explain the formation of a shawl. 9 Imagine you are a tour director for a speleological

society who wants to visit famous caves around the world. On a map draw the location of ten caves formed by karst processes and state what is significant about each cave.

10 Research Ngilgi or Yallingup, located in the Margaret River wine region of WA. Draw a map of the location and discuss how it was formed and managed today.

11 A plan to commercialise Capri’s famous Blue Grotto sea cave by installing floating booms on which businesses could advertise has sparked indignation in Italy. Where is the Blue Grotto located? How was it formed? How is it managed?

12 Caves support a unique community of bacteria, fungi and animals not seen on the surface of the Earth. Research the topic. List unique species and explain how they adapted to their environment.

[Insert aw 01104.1]

[Insert aw 01104.2]

Shawls: sometimes water trickles down a rockface, depositing a narrow strip of calcite. It eventually results in a thin sheet, growing at an angle from the wall. Shawls often contain interesting folds and have rich coloured banding caused by other minerals in the solution, e.g. iron oxide

Flowstones: attractive formations occurring when flowing water leaves a film of calcite. They cover the original rock or mud floor. Sometimes the lower portions hang free, making a fringe or shawl of stalactites

1.18.3 Shawls and flowstones


ISBN 978 1 4202 3265 344


1.19 Above ground: towers, travertine and stone forests

Guilin in China and Halong Bay in Vietnam are formed of karst towers, and Plitvice National Park in Croatia features travertine lakes and waterfalls. These different types of karst landforms are World Heritage Sites.

Karst towers Some karst landscapes feature steep limestone towers. These spectacular 30–300 m high towers with vertical sides were formed by a combination of tectonic uplift and erosion in tropical wet climates. Submerged karst towers on the coast of Thailand and in the Chinese Sea form steep limestone islands. These spectacular landforms have been used as locations for movies, including The Beach with Leonardo DiCaprio.

Halong Bay in Vietnam boasts seascape karst towers. The landscape consists of 1600 islands and islets, most of which are limestone. The formations have developed over the last 20 million years during a warm, wet climate. The landscape is shared with tourists and 1600 people living on floating houses who survive by fishing and aquaculture.

Karst in Guilin, ChinaGuilin is one of China’s leading tourist destinations, with more than 5180 km2 of karst landforms. Limestone peaks resemble giant teeth rising vertically 30–80 m above the green plain.

[Insert aw 01107]

1.19.1 Formation of peaked landscapes in Guilin, China

[Insert aw 01108.1 and .2]

1.19.2 Two of the karst formations in Guilin, China


ISBN 978 1 4202 3265 3


45

Ch

ap

ter 1

The topography is characterised by karst caves, sinkholes, isolated towers and stone forests. The landforms evolved due to a combination of factors:

• they contained hard compact carbonate rock• land was uplifted by the collision of India with

Asian plates to form the Himalayan Mountains• a monsoon climate with high precipitation

during summer• the land was not eroded by glaciers.

Karst collapse is a major geological hazard in the area, with more than 200 cases in China. Furthermore, karst aquifers have been polluted from the discharge of industrial waste into caves.

Travertine Travertine is a form of limestone deposited at the mouth of springs. In Plitvice Lakes National Park in Croatia, travertine has built up over several millennia to form sixteen huge dams and waterfalls, including the 78 m high Veliki slap.

Cascades of natural lakes formed behind travertine dams can be found in Band-e Amir in Afghanistan and Pamukkale, Turkey. Romans mined deposits of travertine for aqueducts, monuments and amphitheatres, and today it is used as paving for patios and garden paths.

Geoactivities 1.19


1 What are karst towers? 2 Name two countries where karst towers are

located. 3 Describe the four conditions for the formation of

karst towers in Guilin. 4 What are the problems facing karst formations in

China? 5 What is travertine and how is it formed? 6 How did humans use travertine?

Inquiry and skills

7 Refer to 1.19.1 and explain how a limestone plain develops from caves to peaks.

8 Refer to 1.19.2, 1.16.4 and the internet. a If you were visiting Guilin in China what five types

of karst landforms might you observe?b What is the main river running through the area?

9 Refer to 1.19.3 and describe travertine formations. 10 Design a pamphlet advertising the importance of

travelling to karst landforms—above and below the ground—for improved geographical understanding of landforms and landscapes.

[Insert aw 01111]

1.19.3 Travertine hot springs in Pamukkale, Turkey

[Insert aw 01112]

1.19.4 Grand Tsingy, Madagascar

Geoinfo

Michaelangelo chose travertine as the material for the external ribs of the dome of St Peter’s Basilica.

Stone forestsKarst stone forests contain a range of pinnacle shapes and colours. A Stone Forest Geopark has been established in Yunnan Province, China, covering an area of 400 km2. The World Heritage listed Grand Tsingy landscape in Madagascar is the world’s largest limestone forest, where high spiked towers of eroded limestone tower over the greenery. Formed 200 million years ago in a lagoon, it created a thick limestone bed. Later tectonic activity elevated the limestone and the sea level fell. Since then the limestone has been eroded by monsoon rains, creating the dramatic landscape there today.


ISBN 978 1 4202 3265 346


1.20 Protecting landforms and landscapes

Jacques Cousteau, the famous French oceanographer and explorer, taught that ‘People always protect what they love’. Yet many unique and beautiful landscapes and landforms that are highly valued still need to be protected.

Protected areasThe International Union for the Conservation of Nature (IUCN) defines a protected area as:

… a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long term conservation of nature with associated ecosystem services and cultural values.

According to the Protected Planet Report, ‘Protected areas remain one of the cornerstones for promoting biodiversity, ecosystem services and human wellbeing’. In 2013, protected areas covered about 13% of Earth’s terrestrial area and around 4% of the oceans (see 1.20.2). Since 1990, the number of protected areas has increased by 58% and their extent has increased by 48%. However, the

report states that many protected areas face management challenges and half of the world’s most important sites for biodiversity are still unprotected.

The Convention on Biological Diversity (CBD) calls for at least 17% of the world’s terrestrial areas and 10% of marine areas to be managed and conserved by 2020. With rapidly increasing global population and the threat of climate change, the need for well-managed protected areas is more important than ever.

[Insert aw 01114] Insert a legend

1.20.1 Distribution of 177 547 nationally designated protected areas, 2012

Source: Protected Planet Report 2012

1.20.2 Growth in the percentage of terrestrial and marine area protected, 1990–2014

Source: Protected Planet Report 2012, UNICEF data 2013

[Insert aw AW01115 to be redrawn]


ISBN 978 1 4202 3265 3


47

Ch

ap

ter 1

Types of protected areasThe IUCN protected area categories include:

Ia Strict nature reserveIb Wilderness areaII National parkIII Natural monument or featureIV Habitat/species management areaV Protected landscape / seascapeVI Protected area with sustainable use of natural

resources.

Landscapes and distinctive landforms underpin all these categories. Most countries, including Australia, use the IUCN categories when protecting important areas.

World Heritage Sites Through the 1972 Convention concerning the Protection of the World Cultural and Natural Heritage, United Nations Educational, Scientific and Cultural Organization (UNESCO) encouraged the ‘identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity’.

To be listed as a World Heritage Site, an area must have outstanding universal value and meet at least one of the 10 selection criteria. The criteria that deal with landscapes and landforms are:

• Criteria 7—superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance

• Criteria 8—outstanding examples of Earth’s history, including significant ongoing geological processes in the development of landforms, or significant geomorphic or physiographic features.

Places that have been listed as World Heritage Sites include coasts, reefs, islands, mountains, arid landforms, karst, ice fields, glaciers, rivers, lakes, tectonic features and volcanoes.

Global Geoparks NetworkUNESCO defines a Geopark as ‘a nationally protected area containing a number of geological heritage sites of particular importance, rarity or aesthetic appeal’. In 2001, UNESCO established the Global Geoparks Network (GGN) to provide an international framework for the protection of outstanding geological heritage. In 2013, there were 91 Geoparks from 27 countries in the GGN. Kanawinka Geopark was Australia’s only Geopark. UNESCO hopes to eventually have over 500 Geoparks in the GGN.

Geoinfo

Nearly 25% of Australia’s national reserve system is managed by Aboriginal and Torres Strait Islander Peoples.

[Insert aw 01117]

1.20.3 Blue Lake, an extinct volcanic crater in Mount Gambier and its surrounding volcanoes are part of Australia’s most extensive volcanic province, the Kanawinka Geopark of southwest Victoria and southeast South Australia

Geoactivities 1.20


1 What is the IUCN definition of a protected area? 2 Outline why protected areas are important. 3 Give statistics to show the percentage of protected

terrestrial and marine areas and their growth. 4 IUCN protects both landscapes and landforms.

Describe the different categories. 5 What are World Heritage Sites? 6 Outline how landscapes and landforms are

included in the UNESCO selection criteria for World Heritage Sites.

7 Explain how the Global Geoparks Network aims to protect geological heritage sites.

Inquiry and skills

8 Refer to 1.20.1 and an atlas. Which countries appear to be underrepresented with protected areas? Why are most European countries well represented with protected areas?

9 Refer to 1.20.2. Describe the progress towards achieving the targets for terrestrial and marine protection.

10 Brainstorm solutions for encouraging developing nations to protect more of their landscapes and significant landforms.

11 Choose a biosphere reserve and write a report on their role in protecting landscapes and significant landforms.


ISBN 978 1 4202 3265 348


GeothinkAssign roles from 1.21.1 and present a role-play of a

meeting discussing the different views for and against the proposal to ‘take action to control beach erosion’. If action is to be taken, suggest the structures and procedures most suitable, for example:

• sea wall—a structure placed close and parallel to the beach preventing erosion and protecting buildings. It is expensive and an eyesore

• offshore breakwater—a structure placed offshore and parallel to the beach. Waves break in deeper water reducing erosion. Destroys surfing and is expensive

Coasts: management and fieldworkRole-play

You live in an attractive beachside town. At a council meeting you express the following concerns about the local beach:

• erosion of the cliff and beach sand from destructive waves

• future tsunami and cyclones and resulting storm surge • climate change with increasing sea levels in the future.

1.22.1 Perspectives on future management of coastal landscape

01118.1 01118.2 01118.3 01118.4

Ethan Elect—Minister for the EnvironmentEthan wants to please residents and reduce loss of lives and property so he will be re-elected. He also wants to attract tourists and businesses to the community. As the government is in debt his budget is tight. He suggests further study into the type of structures and procedures to be implemented.

Audrey ActionAs a naturalist, Audrey is concerned the proposed scheme for an offshore breakwater, seawall or groyne will be an eyesore. She says they will interfere with the natural movement of water and beach sediment and cause a decline in marine species. Audrey proposes the council buys properties on the cliff and foredune and revegetates the dunes.

Sandy DuneSandy lives in a luxury home on the sand dune and fears the loss of property due to sand erosion, especially during storms. The home has been in the family for generations and he plans to leave it to his grandchildren. Sandy feels the council should look after tax-paying residents. He suggests the building of seawalls and offshore breakwaters.

Tom TravellerTom has his holiday here each year as he enjoys the snorkelling, surfing, fishing and whale-watching. The town also offers activities such as movies, skating rinks, parks and shops. He would like the council to protect the beach or he will find a new holiday location. This will mean loss of business to the community.

01118.5 01118.6 01118.8 01118.9

Ben BuilderBen is an engineer and has suggested both a seawall to stop erosion and a groyne in front of the swimming area. He wants to bid for the construction contract and intends to focus on negative publicity the council will receive from loss of lives, damaged homes and reduced number of tourists if erosion and future coastal disasters occur.

Sally SurferSurfing is Sally’s main recreational activity and is unhappy about seawalls, groynes and an off shore breakwater as they would destroy the waves. She and her friends would be forced to travel to beaches further away with poorer surfing conditions if waves changed. Less money would be spent in local shops.

Cheri Cliff-hangerCheri owns a cliff-top motel and coffee shop, which bring money and jobs into the community. Her business attracts tourists who watch whales. She fears erosion by waves will undercut the cliff and it will collapse. Cheri blames the council for allowing construction on top of an eroding cliff and favours an off-shore breakwater.

Charlie ChairpersonCharlie is the local councillor and listens to all the different views and asks further questions when necessary. He provides a brief summary at the end of the presentations and then conducts a vote for and against the proposal to take action.

If a proposal is passed consultation with experts will be required.


ISBN 978 1 4202 3265 3


49

Ch

ap

ter 1

• groyne—a structure to stop longshore drift and trap sand. It maintains the beach but is an eyesore

• beach nourishment—artificial placement of sand. Dredged from other places and is a continuous process. Needs money but has a low environmental impact on the beach

• purchase property—the removal of buildings. Loss of revenue to the council. Allows natural beach processes to continue. Increases public access to the beach.

At the end of the meeting, the group votes on whether to proceed with the proposal and if so, how. Present a short report to be published in the local newspaper.

Fieldwork

Australia contains 37 000 km of coastline, 11 000 beaches, and stunning landforms such as the Twelve Apostles, the Great Barrier Reef and Fraser Island. Despite their beauty, coastal environments are under stress from natural processes such as cyclones, storm surges, tsunamis and increasing sea levels. They are also under pressure from humans. Tourism and increasing population drift to coastal areas has led to the clearing of wetlands and foredunes for high-rise development.

• How have humans impacted on coastal processes?

• What should we do about coastal erosion?• How can we reduce the impacts of tsunamis and

sea-level rise on coastal areas?2 Conduct fieldwork by observing, collecting, recording

and interpreting information on the processes operating at a local beach. If this is not possible, use Virtual Fieldwork sites and YouTube. a Before going to the beach, draw a sketch map

using an atlas or the internet locating the beach. Include latitude, longitude and scale.

b When at the beach draw an annotated diagram of coastal landforms including:– natural features e.g. cliff, rock platform, cave,

wave cut notch, beach, foredune, spit, lagoon and vegetation

– human features e.g. car park, surf club, park, homes, roads and garbage

3 Observe the waves and answer the following questions:a Are the waves breaking at right angles or

obliquely?b Estimate the height of the waves.c What is the time between the waves?d Are the waves spilling, plunging or surging?e Can you see a rip? Where is it located? What are

the problems of swimming in rips?f Can you see surfers? At what part of the beach

are they located and what part of the surf?g What is the clarity of the water? (clean, dirty?)h What evidence can you see that sand is moved in

the surf?i In which direction is the waves moving the sand?j How far does the water run up the beach at

high tide?4 On the sand:

a Collect a handful of sand close to shore and at the back of the beach near the foredune. What are the differences in size of the grain and particles such as shell content? Give reasons for the differences.

b Is the beach patrolled? Where are the flags located? Why are they located at this spot?

c What evidence can you find that the sand is eroding and/or the cliff is eroding?

d Imagine you came back to the beach in a million years. Describe the scene.

5 Prepare your presentation.a Present fieldwork as a poster, PowerPoint or

multimedia display. Include a map of the beach, sketches, diagrams and photographs.

b Where appropriate, propose individual and group action.

insert AW01120

1.21.2 Fraser Island

Fieldwork on coastal processes enables people to better understand how beach environments work so they can propose sustainable management strategies.

1 Develop inquiry questions such as:• How has the coast changed over time?• What are the natural impacts on coasts?


ISBN 978 1 4202 3265 316

GeoWorld 8: Australian Curriculum OVER MATTER

CHAPTER 10 PAGE 301

11 Refer to 10.1.4.a Which urban places will house most of Australia’s

future population growth?b Identify two types of regional cities.c Explain your understanding of a satellite city.d If Australia were to build satellite cities what else

would be needed?e Explain which urban areas would grow through a

policy of decentralisation.

CHAPTER 10 PAGE 305

insert AW10013 – can be cut if not enough space

10.3.3 Sydney Metropolitan Area

• There is a push is to model Australian cities on London, Tokyo and Singapore, which have twice as many people and jobs per hectare as Sydney.

CHAPTER 10 PAGE 311

• Past efforts at decentralisation in Australia focused on government incentives for industries to relocate in the hope people would follow the jobs.

200913_GeoWorld8AC_OM_1pp.indd 16 11/10/13 10:11 AM

Date post:	29-Mar-2016
Category:	Documents
Upload:	macmillan
View:	227 times
Download:	2 times

GeoWorld 8

Documents