Geodynamics forIntroduction of Geophysics
Exploration
Syamsu Rosid
Geophysics Study ProgramsDept. of Physics, University of Indonesia
(7 – 50 km thick)
The Earth’s Interior
Illustration of
Convection Flow
Plate Tectonic: Sea-floor spreading and Subduction zone
The Spreading Zone
SubductionZone
Some processes at a convergent boundary
Geological Structure
Folded and faulted sedimentary beds at Palmdale, California
Folded rock, Calico Hills, California
dekat Jabal Tsur, Saudi Arabia
Open folds in Spain
Isoclinal folds from northeastern Nevada
Overturned Anticlined from northern California
Recumbent folds in the Alpins
Faults
Faults in Big Horn Mountains, Wyoming
Normal faults with prominent horst block offsets volcanic ash layers in southern Oregon
San Andreas Fault, California
The system is in a belt approximately 100 km wide and1300 km long that extends into Mexico. Los Angeles isslowly moving towards San Francisco because of San Andreas fault motion of 2 cm/yr. 5 million yrs ago the fault was blue line. In the future it may jump in green zone
Los Angeles
San Francisco
Karangsambung, Kebumen, Jateng
Earthquake’s Mechanism
Kobe’s earthquake in Januari 1995> 5000 people killed> 27000 people injured> 88,000 buildings destroyed or damaged> US$ 400 billion
at Stanford University, EQ 1906
Near Castaic Junction, north of Northridge, EQ 1994
Northridge Meadows Apartments, EQ 1994southern California.
Northridge EQ, 1994
Horizontal offset in El Centro, California 1979
Gallatin Mounty, Montana, 1959Compression of freeway, San Fernando Valley, California, 1971
Uplift of the sea floor associatedwith the Alaskaneartquake, 1964.The block of rockon the right (reef) has been dis-placed upward as much as 5 m.
Pahoehoe eruption in Hawai, 1972
An aa flow in Hawai, 1983
A spatter cone (1 m height) erupting in HawaiEruption of pyroclastic of Cerro Negro in Nicaragua
Pyroclastic flow at Mayon volcano, Philippines, 1984
Crater (foreground) and caldera in Kamchatka, Russia Cerro Negro, Nicaragua
Pyroclastic flow on Montserrat, August 4, 1997.
On 24 August AD79, Mt Vesuvius, near Naples (Italy)erupted and killed at least 2000 people and covered theRoman town of Pompeii.
A river of molten rock of Kilauea, Hawai, 1994
Layers of lava and ash
Thick ribbon of lava at Kimanura, Zaire.
Giant cinder cones at Mt Etna, Sicily.
Mt Etna has probably Been active for more than 2.5 m yr. More than 110eruption recorded since1500 BC. The long eruption is in 1992.
Rich paddies in Bali, Indonesia
Grape vines at Mt. Etna, Sicily, Italia
Rocks Mechanism
Columnar basalt at Devil’s Postpile,California. From above and side
Columnar basalt of Giant’s Causeway on the coast of County Antrim in Northern Ireland
MetamorphRock
Metamorphosed conglomerate
Breksiconglomerate
Sedimentation mechanism
Pembentukan sedimen
Arus erosiSandstone at Zion National Park, Utah
Sandstone formed from ancient sand dunes, Arizona
An oxbow lake at Sweetwater River, Wyoming
Tanah Longsor Earthflow in March, 1995 at La Conchita, California
Pelapukan batuan
Weathering and erosion of rock at Lees Ferry, ArizonaWind erosion of basalt outcrop, Death Valley, California
weathering, bedding in sandstone and shale in Utah
Mexican Hat in the Utah Desert, North AmericaWind-sculpted ridges are in the Atacama Desert in Chile and in the Sahara Desert in Africa. These yardangsare hundreds of meters high and dozens of kms long.
Untuk apa ???
Coal
Intrusi Lanzarote dike (and sill) in the Canary Islands
Bingham Canyon copper mine in UtahCopper mine at San Zavier, Arizona
Gravity measurement
Oil Reservoar
Geotermal (Panas Bumi)
Boiling tar in NZ
Lady Knox geyser at Waiotapu, NZIceland’s Strokkur geyser, satu dari ratusangeyser di Iceland. Geysir= upwards force
Rekreasi dan pengobatan
A hot spring at Yellowstone Nat. Park, Wyoming
Lightning
Sunlight streams at Maui Island, Pacific Ocean
The air surrounding lightning often rises to 30,000 C