Bell Ringer

1) At this type of plate boundary, the plates move away from each other. Magma rises to the surface, creating new crust as it cools. a) Transform Plate Boundary b) Convergent Plate Boundary c) Divergent Plate Boundary d) Subduction Zone e) Convergence Zone

2) Metamorphic rock, such as slate and shale, is formed… a) As magma released from a volcano cools slowly as it flows over the surface of the earth as lava.

b) As magma is ejected from a volcano and cools quickly, differentiating into clusters.

c) As pieces of minerals and other rocks are crystallized together through lithification.

d) As rocks experience heat and pressure, reshaping crystals within the rock.

e) Through a continuous process of heating and cooling from an underground magma source.

3) Volcanoes are created as one plate slides beneath another one. The crust is melted and comes to the surface as magma. This process is known as… a) Subduction b) Lithification c) Volcanism d) Transformation e) Convergence

4) Identify each of the plate boundaries shown below:

A B C

Earthquakes

Inside the Earth

• The earth’s crust sits atop the mantle – a thick layer of “solid” (but moveable) molten rock.

• At the center of the earth is the core – a molten, heavy layer made mostly of iron.

Inside the Earth

• The earth’s crust sits atop the mantle – a thick layer of “solid” (but moveable) molten rock.

• At the center of the earth is the core – a molten, heavy layer made mostly of iron.

• As one descends deeper into the

earth, the temperature

vastly increases.

Just the Facts

• .5% of earth is crust (oceanic and continental)

• 99% of earth’s crust is made of 8 elements: oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium

• Moho

• Lava in the earth magma when in reaches surface, igneous when it cools

Inside the Earth

• Heat within the earth drives currents that flow in loops in the mantle.

• The mantle’s soft rocks move upward as it is heated and downward as it is cools. (convection currents; energy transformaiton)

Inside the Earth • The cyclical movement of the mantle beneath

moves the plates of crust sitting upon it.

• Earth’s fifteen plates move, on average, 1-6 inches a year.

Inside the Earth • The movement of plates has profoundly

influenced life on earth.

• 225 million years ago, scientists believe all the continents existed as one mass- Pangaea.

Inside the Earth • The movement of the mantle has caused the

continents to drift apart, leading to the world we know today.

Earthquakes • The movement of the mantle can cause stress

to build up in the earth’s crust.

• The crust can only take so much stress before fracturing and moving – causing an earthquake.

Earthquakes • Most earthquakes occur at the boundaries of

tectonic plates, as plates collide or slide past each other.

• Movement can also occur at fault lines – cracks in the earth’s crust caused by previous earthquakes.

Earthquakes • Most earthquakes occur at the boundaries of

tectonic plates, as plates collide or slide past each other.

• Movement can also occur at fault lines – cracks in the earth’s crust caused by previous earthquakes.

San Andreas Fault

Earthquakes

Earthquakes

Earthquakes

Earthquakes

Earthquakes

Kentucky’s largest earthquake occurred in July, 1980. It was registered as a 5.1

Earthquakes • The origin of an earthquake, the focus, is

often far below the earth’s surface.

• The earthquake’s epicenter is the location, on the earth’s surface, directly above the focus.

Earthquakes • As the crust moves to relieve stress, energy in

the form of seismic waves move outward from the earthquake’s focus (like ripples in a pool).

• These waves result in vast damage as they cause the earth to move.

Earthquakes • The severity of an earthquake is determined

by the magnitude of its seismic waves.

• The wave magnitude is measured by a seismograph.

Earthquakes • Scientists use the Richter scale to assign a

“strength” value to each earthquake.

• The Richter scale goes from 1 – 10, with each subsequent value indicating a ten-fold increase in seismic wave magnitude (and ground shaking).

• ex: An earthquake measured as a 6.0 on the Richter scale is ten-times as powerful as a 5.0 earthquake.

Earthquakes • Scientists use the Richter scale to assign a

“strength” value to each earthquake.

• The Richter scale goes from 1 – 10, with each subsequent value indicating a ten-fold increase in seismic wave magnitude (and ground shaking).

• ex: An earthquake measured as a 6.0 on the Richter scale is ten-times as powerful as a 5.0 earthquake.

The largest earthquake ever measured occurred in 1960 in Chile – a 9.5

Earthquakes • Scientists are beginning to also use a second

scale, the Modified Mercalli Scale, to rate the strength of the quake.

• This scale uses direct observation and personal accounts to classify the quake – the scale ranges from 1 (insignificant) to 12 (catastrophic)

Earthquakes • The primary effects of earthquakes include

shaking and displacement of the ground.

• These effects can have serious consequences for people, buildings, roads, bridges, etc.

First Hand Accounts - Quakes

Tsunamis

Tsunamis • Earthquakes occurring on the ocean floor can

result in tidal waves or tsunamis.

• Tsunami – a series of large waves generated when part of the ocean floor suddenly rises or drops.

Tsunamis • Most large tsunamis occur at subduction

zones, as one plate slips under another; the rise of the sea floor creates the tsunami.

Tsunamis • The tsunami waves move rapidly at sea – as

they approach land, they slow down but grown in height.

• As they hit land, they can cause great damage.

December 26, 2004 • An underwater earthquake, magnitude 9.15,

occurs in the Indian Ocean creating the worst tsunami to date.

• Waves approaching land were as high as 100 feet and devastated regions of Thailand, Sri Lanka and Malaysia.

• 228,000 people were killed.

First Hand Account - Tsunamis

Exit Slip

1) Where do earthquakes occur? a) Along fault lines b) Along the borders of tectonic plates c) Along the interior of tectonic plates d) A and B e) B and C

2) Which answer has the parts of the earth labeled correctly: a) 1=Mantle, 2=Core, 3=Crust b) 1=Crust, 2=Mantle, 3=Core c) 1=Core 2=Mantle 3= Crust

d) 1=Crust 2=Core

3= Mantle

3) Which answer best describes how a tsunami forms?

a) Seismic waves from an earthquake along a fault line on land move to the sea, where they cause waves to build and rush toward land.

b) The movement of the mantle shifts the tectonic plates, causing them to move apart, creating a wave that rushes toward shore.

c) A transform plate boundary under the sea moves apart, create seismic waves that propel the water toward the shore.

d) At a subduction zone under the sea, part of the crust rises, creating a wave that rushes toward land.

e) Magma from the mantle rises, heating the water and causing it to rush toward the shoreline.

4) The Modified Mercalli Scale is used to determine the strength of earthquakes. Which answer below describes this scale? a) It measure’s an earthquakes seismic waves using a seismograph and plots them on a scale from 1 to 10 b) It measure’s the displacement of the earth and plots this displacement on a scale from 1-5 c) It uses first-hand accounts to determine the strength of the quake, plotting it on a scale from 1-12 d) It measures the seismic waves eminating from the focus; the waves are measured on a seismograph and plotted on the Richter Scale.

California Earthquake of 1906

• The worst earthquake in North American history occurred at 5:12am on April 18, 1906.

• Movement along the San Andreas fault caused the quake; shaking was felt as far away as Oregon and Nevada.