38695947
Description
Flashcards by Sasha Maric, updated more than 1 year ago
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Created by Sasha Maric
over 1 year ago
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| Question | Answer |
| Crust/Lithosphere |
The Lithosphere is the outer most layer of the earth and includes the crust and the upper mantle. It is about 100km long and made of rocks and minerals.
Image:
Cutaway Earth (image/jpeg)
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| Mantle/Asthenosphere | The Asthenosphere is the soft layer of the mantle underneath the lithosphere on which the tectonic plates move. The mantle is about 2,900km and consists of silicates. _______________ Extension - The tectonic plates move on top of the mantle which consists of lava. Once these plates begin to move they cause different boundaries to form. |
| Core |
The earths core is the inner most geological layer of the earth. It has a radius of around 1,220 km and is made of metal specifically iron and nickel.
Image:
Cutaway Earth (image/jpeg)
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| Divergent/constructive margins/boundaries |
A divergent boundary occurs when two tectonic plates move away from each other. In these boundaries magma rises from the mantle to the surface creating a new crust.
Image:
Ef Plate P3 (image/gif)
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| Convergent/destructive margins/boundaries | When two tectonic plates come together they create convergent boundaries. Mountains can form as well as a subduction zone below after the plates slide against each other. |
| Ridge push | Describes the intrusion of magma into the spreading ocean ridges. _______________ Extension- An example of a ridge push would be the Mid-Atlantic Ridge which propels plates apart. |
| Slab pull |
Where cold, denser oceanic lithosphere sinks due to gravity into the subduction zones.
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Image083 (image/png)
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| Sea floor spreading extension – mid-ocean ridge | Describes the process of creating of new oceanic lithosphere at the ocean ridges and the divergence of the new lithosphere on either side of the ridge. Lava rises to the surface under the ocean and cools quickly in contact with the sea water. ______________ Extension - The mid-ocean ridge is an extensive underwater mountain range resulting from the constantly altering tectonic plates, heat, and magma emitted from the earth’s core. They occur mainly from divergent plate boundaries. |
| Island arcs | Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. |
| Subduction zones extension – Benioff zones | A subduction zone is a region in which a portion of a tectonic plate sinks beneath another plate into the Earth's interior. Found on convergent plate boundaries. _________________ Extension - Benioff zones are zones of earthquake activity along the upper portion of a sinking plate, as it scrapes past the opposing plate, in a subduction zone. |
| Ocean trenches | Ocean trenches are long, narrow depressions on the seafloor. Dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench. |
| Transform faults/boundaries | Two tectonic plates that slide pass each other. They usually cause earthquakes to occur. |
| Seismic activity | The types, frequency and size of earthquakes that occur due to tectonic movement. _________________ Extension - The Ring of Fire is a string of volcanoes and sites of seismic activity around the edges of the Pacific Ocean. |
| Volcanic activity | Volcanic activity is the direct emission of various tracer constituents into the atmosphere, which causes changes in the chemical composition of the atmosphere. __________ Active volcanoes erupt regularly examples of active volcanoes are Kilauea in Hawaii, Mount Etna in Italy and Mount Stromboli also in Italy. |
| Shallow/deep focus earthquakes | Earthquakes less than 70 km deep are classified as shallow focus. Earthquakes deeper than 70 km are classified as deep focus. It is also the place where the earthquake originates. |
| Fold mountains | Fold mountains are formed by the effects of folding on layers within the upper part of the Earth's crust. They are created where two or more of Earth's tectonic plates are pushed together. ____________ Extension - The Himalayas, Andes, and Alps are all active fold mountains. |
| Freeze-thaw action/Frost shattering | Where water trickles into the cracks of rocks, usually during the day, and then freezes during the night. This force rocks open. _________ Extension - The freeze-thaw action can be causes of mass movements such as rockfalls. The weathering causes the rocks on the mountain to begin falling down a slope. |
| Exfoliation |
Exfoliation is a process in which large flat or curved sheets of rock fracture and are detached from the outcrop due to pressure release.
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Exfoliation (image/png)
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| Dilatation | Also known as unloading; affects areas where the ground surface is lowered by erosion. When the top layers of rock is worn away, rocks underneath form cracks parallel to the surface. |
| Salt crystallisation | This occurs when salt solutions in the pores or joints of rocks crystallize. The crystals then expand and force the rock apart. ____________ Extension - When the water from limestone and chalk evaporates the salt crystals are left behind to form salt solutions of sodium sulfate or sodium carbonate. |
| Hydration | Wetting and drying can cause the addition or removal of water from the molecules of some minerals, causing expansion or contraction which assist disintegration. |
| Hydrolysis | Where water and chemical compounds in a rock meet, resulting in the decomposition of the rock surface by forming new compounds. ________________ Extension - For example acidic water reacts with feldspar to produce kaolin. |
| Carbonation | Where water mixes with carbon dioxide, forming carbonic acid which can disintegrate rock. ____________ Extension - Carbonation takes place when rain combines with carbon dioxide to form a weak carbonic acid which reacts with calcium carbonate (the limestone) and forms calcium bicarbonate. |
| Oxidation |
Where water meets with metals in rock, which is then exposed to oxygen, then forming rust.
Image:
20.8.1 A (image/jpeg)
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| Chelation | The chemical removal of metallic ions from a mineral or rock by weathering _______________ Extension - The decomposition of dead plants in soil may form organic acids which, when dissolved in water, cause chemical weathering. |
| Humic acid | The decomposition of dead plants in soil may form organic acids which, when dissolved in water, cause chemical weathering. |
| Effects of acid rain | acid rain can land on statues, buildings, and other manmade structures, and damage their surfaces. _______________ Extension - Acid rain leaches aluminum from the soil. |
| Granular disintegration |
Produces sand in deserts; rates depend on different minerals, the different axes of a crystal, and size of crystals, and colors of rocks.
Image:
01 04 (image/jpeg)
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| Block disintegration | The splitting of rocks along the joints into blocks is called block disintegration. |
| Joints | A joint is a type of extension fracture formed by movement of the rock in a direction perpendicular to the plane of fracture. __________ Extension - Mural joints: common in granites and related plutonic rocks and some hypabyssal rocks. Sheet joint: In this case there is one set of prominent joints parallel to the ground surface whose spacings generally increase with depth and a second set running at right angles. |
| Bedding planes | A bedding plane is defined as a surface representing a contact between a deposit and the depositing medium during a time of change. |
| Shear stress & shear strength | shear stress, force tending to cause deformation of a material Sheer stress is the amount of stress a slope or material can contain. |
| Free face, convex, concave slope | Free face: An outcrop of rock which is too steep for the accumulation of soil and rock debris. Convex: A convex slope is a slope that steepens as it descends. Concave slope: A slope that decreases in steepness as it loses elevation. |
| Heave |
Upwards swelling of soil due to freezing and thawing conditions; a form of creep.
Image:
Untitled (image/png)
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| Flow |
Rapid movement of rock and weathered debris mixed with water down valleys; often referred to as mudflows. Flows are linked to steep slopes, narrow valleys, removal of vegetation and construction projects, a thick regolith heavy rainfall to saturate the ground, a slope failure or slide that may trigger the flow, and earthquakes or traffic vibration.
Image:
Mud Slide (image/png)
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| Fall | Rocks that fall from vertical faces. This can happen through the undercutting of the base of a cliff by a river or the sea, or through glacial activity. |
| Slide slump |
The name given to a slide when the underlying failure surface is curved rather than planar.
Image:
Slumping (image/png)
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| Soil creep | Describes the slow, unconsolidated material and soft rocks. Can occur as a result of: clay-rich material which is liable to plastic flow; freezing and thawing of water on the surface layers Describes the slow, unconsolidated material and soft rocks. Can occur as a result of: clay-rich material which is liable to plastic flow; freezing and thawing of water on the surface layers |
| Slides (Landslide, mudslide, debris slide) |
Events where a section of a hillside becomes unstable, shears away, and moves downhill. Factors leading to slope failure include slope angle, geological structure, rock type, amount of water present, removal of the toe landslip, loading of the head of the slope, and vibrations.
Image:
Landslide (image/png)
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| Avalanche | An avalanche is a rapid flow of snow down a slope, such as a hill or mountain. |
| Rotational slip | The semicircular motion of a mass of rock and/or soil as it moves downslope along a concave face. |
| Intentional (e.g. mining, quarrying, spoil heaps, stabilising slopes, coastal management) | Intentional acts done to anything related to geography. ______________ Extension - Examples of intentional would be mining - the process of extracting useful materials from the earth and quarrying - the process of removing rock, sand, gravel or other minerals from the ground in order to use them to produce materials for construction or other uses. |
| Unintentional (e.g. effects of acid rain, deforestation, overgrazing by animals, landslides where favelas have been built on steep slopes) | Unintentional acts done to anything related to geography. _______________ Extension - Examples would include effects of acid rain - acid rain can land on statues, buildings, and other manmade structures, and damage their surfaces. and overgrazing by animals - excessive and continuous grazing, which causes damage to grass or rangelands. |
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