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34 Cards in this Set
- Front
- Back
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Craton |
The very old, very stable mass of mostly metamorphic rock that makes up the interior of the continent |
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Orogeny |
Mountainous area. Also refers to an episode of mountain building. |
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Terrane |
Piece of the earth's crust that formed at one location and was moved to another by plate motion |
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Tectonics |
All about relief - the distance between high and low points. |
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Earthquake |
Shaking of the ground cause by a release of energy deep inside the earth |
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Focus |
The place underground where energy Is released that causes an earthquake |
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Epicentre |
The point on the surface directly above the focus |
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Seismograph |
An instrument used to measure ground motion |
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Types of earthquake waves |
p and s waves |
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P: primary wave |
Faster Causes objects to more back and forth |
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S: secondary waves |
Slower Causes objects to move up and down and sway |
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Stress types |
Compression Tensional Sheer |
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Strain |
The way a rock responds to stress - either bend or break |
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Brittle strain |
Rocks, when dripped or have a large amount of force inflicted on them are able to resist it until they break or shatter |
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Tsunami |
Large waves caused by a seismic event, often an earthquake. These waves are very fast. Also have a very long wave length and low amplitude in the open ocean |
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Faults and folds |
When a rock us stressed it will either bend or break |
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Folds |
WHen a rock bends Compressive Shear Tensional |
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Fold: compressive |
Produces symmetrical folds |
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Folds: sheer |
Produces asymmetrical folds |
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Folds: tensional |
Does not result in folding |
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Faulting |
When a rock breaks Reverse Normal Strike slip |
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Fault: reverse |
Caused by compressive stress |
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Fault: normal |
Caused by tensional |
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Fault: strike slip |
Caused by shear stress Right lateral or left lateral |
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Volcanoes |
Hill or mountain that forms over a hole in the earth's crust out of which comes melted rock or lava, solid rock particles and gas |
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Historic volcanic eruptions |
1. Mt mazama 6600yeasr 2. Mt Vesuvius 2000 3. Mt St Helen may 18 1980 |
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Effusive ie. Hawaii |
Oceanic plate Mafic rock Low viscosity lava Low amounts of gas High eruption frequency Long duration of eruption |
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Explosive ie. Mt Vesuvius |
Continental plate Felsic rock High viscosity lava Hugh amounts of trapped gas Low frequency of eruption Short period of eruption |
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Types of volcano |
Composite and shield - based on appearance |
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Composite / strato volcano |
Explosive Tall, steep sided and isolated structures Made of alternation lava layers and pyroclastic debris Big pile of loose unconsolidated rock - prone to failure - the loose rock on the steep sides or the volcano can slide / fall off even if the volcano is not erupting |
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Shield volcano |
Effusive Low, dome like structure with gently dipping sides Lower and wider than a composite volcano |
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Volcanic gases |
Most common types are: H20, CO2, or acidic compounds (hydrofluoric and hydrochloric acid) |
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Super volcanoes |
Complex of volcanoes Area that is volcanically active If all these complexes erupt at once, it may produce a much bigger eruption |
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Gases can have significant consequences |
H20 can generate local weather conditions CO2 can remain in the atmosphere and contribute to climate change Acid compounds can damage plants and animals in the immediate vicinity and change H2O chemistry |
