Lempeng Tektonik

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