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Deepest Place on Earth: Introduction to Plate Tectonics and how we discovered the dynamics of our planet. Explains how science experiments are carried out for things we either can't or have a difficult time observing with our own eyes. |
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How Tall Can Mountains Be?
With all this discussion about how plate tectonics creates things like trenches and mountain/volcanoes,. And knowing how high the convergent boundary between India and Asia has pushed the Himalayan mountains, is there a limit to how high a mountain can possible be? |
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San Andreas Fault:
Shows how geologists discover and map faults based upon earthquake evidence. Looks at the great San Fransisco earthquake and how we have been able to determine so much about how the fault works from looking at geologic features. Also spends a good deal of time discussing earthquake prediction and why/where we think the next "Big One" will hit. |
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Volcanoes are grouped into four types:
Cinder Cones are circular or oval cones made up of small fragments of lava from a single vent that have been blown into the air, cooled and fallen around the vent. Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from high-viscosity lava, ash and rock debris. Mt. Rainier and Mount St. Helens are examples of this type of volcano. Shield volcanoes are volcanoes shaped like a bowl or shield in the middle with long gentle slopes made by basaltic lava flows. Basalt lava flows from these volcanoes are called flood basalts. The volcanoes that formed the basalt of the Columbia Plateau were shield volcanoes. Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent. The eruption of Mount St. Helens in 1980 was caused in part by a lava dome shifting to allow explosive gas and steam to escape from inside the mountain. |
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