Term
| Four main branches of geophysics |
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Definition
1. Seismic wave
2. Gravity
3. Heat flow
4. Magnetic field |
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Term
| __ % of Earth's surface is covered by oceans |
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Definition
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Term
| Where did oceans originate? |
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Definition
| Primarily from volcanic degassing of water vapor from interior of the primordial Earth. A small amt may have come from comets impacting earth. |
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Term
| How can we sample sea floor rocks and sediments? |
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Definition
| Rock dredges, seafloor drilling, submersibles |
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Term
| Active continental margins |
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Definition
| have continental shelves and slopes. Slopes lead to deep oceanic treanch |
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Term
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Definition
| encircles globe. Runs down center of an ocean & numerous conical seamonts rise from sea floor |
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Term
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Definition
| seaward sloping (o.1 degree). few km to >500km. Covered in young sediment |
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Term
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Definition
| Steep slope (4-5 degree) extending from edge of continental shelf to deep sea floor |
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Term
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Definition
| V-shaped valleys that run across continental shelves & down slopes. Deliver continental sediments to abyssal fans on deep sea floor sometiems by turbidity currents |
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Term
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Definition
| gently seaward sloping (0.5 degree) wedges of sediment extending from base of slope to deep sea floor. Ending in abyssal plains at 5km. Lie upon oceanic crust. Sediment deposited by turbitdity & contour currents |
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