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43 Cards in this Set
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How does frost wedging work? And in what climate would you expect it to have the most effect? |
A type of mechanical weathering caused by frost and ice. It is caused by repeated freeze-thaw cycle of water in extreme climates. The rainwater goes through the small cracks in the rocks (joints) and as temperature cools down, the water freezes and expands the rock |
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What is mechanical and chemical weathering? |
Mechanical/physical weathering - physical disintegration of a rock into smaller fragments, each with the same properties as the original. Occurs mainly by temperature and pressure changes. Chemical weathering - process by which the internal structure of a mineral is altered by the addition or removal of elements. |
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How are mechanical and chemical weathering different from each other? |
Mechanical weathering physically breaks rocks into smaller pieces. Chemical weathering changes the surface of rocks into new substances, such as rust. |
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Which common rock forming minerals would be expected to weather most quickly? |
Using the Goldich Reaction series, we see that Olivine, CA-rich Plagioclase, Pyroxene, and Amphibole dissolve the quickest. |
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How much of the Earth's surface is covered with water? |
71% of the earth is covered with water |
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What are the basic characteristics of ocean trenches? |
Ocean trenches are natural tectonic plate boundaries between two crustal plates. When a continental plate converges with an oceanic plate a subduction zone forms. The heavier oceanic plate subducts beneath the lighter continental plate forming a trench. |
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What are the major differences between passive and active continental margins? List the major examples of each |
Active: An active continental margin is found on the leading edge of the continent where it is crashing into an oceanic plate. An example is the west coast of South America. Active margins are commonly the sites of tectonic activity: earthquakes, volcanoes, mountain building, etc Passive: Passive continental margins are found along the remaining coastlines. Because there is no collision or subduction, tectonic activity is minimal. The Amazon River drains across South America to the coast, where it enters the Atlantic Ocean and deposits sedimentary materials. |
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How is the majority of groundwater used in the united states? |
The largest amount of groundwater is used for irrigating crops. Local and county departments also withdraw water for things such as delivering water to local businesses, fire fighting, and public uses of water such as local pools. |
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What is porosity and permeability? |
Permeability: the property of rocks that is an indication of the ability for fluids to flow through rocks. High permeability will allow fluids to move rapidly through rocks. It is affected by the amount of pressure in a rock. Porosity: consists of the tiny spaces in the rock that hold the oil or gas. The higher the porosity amount, the more fluid that a rock may contain. |
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How does mass wasting differ from other erosional processes? |
Definition: the large movement of rock, soil and debris downward due to the force of gravity. In other words, the earth's outer crust is being 'wasted' away on a 'massive' scale and falling to lower elevations. It is just gravity, there is no other outside force acting on the rocks such as chemical change or nature. |
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What are the rates of mass wasting? |
Slope Failures - a sudden failure of the slope resulting in transport of debris down hill by sliding, rolling, falling, or slumping.
Sediment Flows - debris flows down hill mixed with water or air. |
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What is a landslide scarp? |
A scarp is a steep (nearly vertical) region of exposed soil and rock at the head of the landslide where the failure surface ruptures the ground surface.
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Explain the Hydrologic Cycle |
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What does capacity and competency mean in relation to sedimentary transport by rivers? |
Stream capacity: refers to the maximum mass of the sediment that a stream can transport. This depends on the dimensions of the stream, the speed at which water flows, and characteristics of the sediment that is being transported. Stream competency on the other hand refers to the maximum size of the particles that can be transported by a stream. |
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What is the angle of repose in relation to dunes? |
The steepest angle of descent or dip relative to the horizontal plane to which a material can be piled without slumping. At this angle, the material on the slope face is on the verge of sliding. |
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Describe the global circulation patterns which create arid regions. Also, know what latitudes those deserts tend to occupy. |
The major deserts of the world lie in close relation to the equator. They lie in the Horse Latitudes, where constant high-pressure systems drive away the rain clouds, and swirl above the earth because of global temperature variations and the Coriolis Effect produced by the earth's rotation in space. |
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What is saltation? |
A specific type of particle transport by fluids such as wind or water. It occurs when loose material is removed from a bed and carried by the fluid, before being transported back to the surface.
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List the locations and relative sizes of the current ice sheets |
The Antarctic Ice Sheet: 5.4 million square miles, contains 7.2 million cubic miles of ice. The Greenland Ice Sheet: 656,000 square miles, covering most of the island of Greenland in ice. |
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How do icebergs in the North Atlantic Ocean originate? |
The main origin of the icebergs that reach the North Atlantic Ocean are the 100 or so major glaciers of West Greenland. Between 10,000-15,000 icebergs are calved each year, primarily from 20 major glaciers between the Jacobshaven and Humboldt Glaciers. |
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What forces drive the size of ocean waves? |
The winds cause waves on the surface of the ocean. The wind transfers some of its energy to the water, through friction between the air molecules and the water molecules. Stronger winds (like storm surges) cause larger waves.
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Why do waves feel bottom, and at what depth do they do so? |
When the wave "feels" the bottom, this means that the water depth affects the properties of the wave. Waves feel the bottom when the depth of the water is less than half the wavelength
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What are longshore currents and what kind of depositional features do they create? |
Longshore current: An ocean current that moves parallel to shore. It is caused by swells sweeping into the shoreline at an angle and pushing water down the length of the beach in one direction Longshore drift is created in this way: Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. So longshore drift moves sediment along the shore. |
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List and explain the Laws of Stratigraphy |
1. Original Horizontality- all sedimentary rocks are originally deposited horizontally. 2. Lateral Continuity- sedimentary rocks are laterally continuous over large areas. 3. Superposition- In any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom. 4. Cross-Cutting Relations- If a body or discontinuity cuts across a stratum, it must have formed after that stratum. 5. Law of Inclusions- this law states that rock fragments (in another rock) must be older than the rock containing the fragments. 6.Law of Faunal Succession- This law recognized that fossil groups were succeeded by other fossil groups through time. This allowed geologists to develop a fossil stratigraphy and provided a means to correlate rocks throughout the world. |
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What are index fossils, and how are they used by geologists? |
Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages). |
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What are the major characteristics of the Precambrian, Paleozoic, Mesozoic, and the Cenozoic eras? |
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In what periods did the major groups of animals first appear? |
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What are the components of the Climate System? |
Cryosphere: The cryosphere is the frozen water part of the Earth system. This includes frozen parts of the ocean, such as waters surrounding Antarctica and the Arctic.
Geosphere: Describes all of the rocks, minerals and ground that are found on and in Earth. This includes all of the mountains on the surface, as well as all of the liquid rock in the mantle below us and the minerals and metals of the outer and inner cores.
Hydrosphere: Is made up of all the water on Earth. This includes all of the rivers, lakes, streams, oceans, groundwater, precipitation, glaciers and moisture etc.
Biosphere: The biosphere includes all life on earth.
Atmosphere: The envelope of gases surrounding the earth or another planet
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How are oxygen isotopes used to determine previous climate conditions? |
By determining how the ratio of heavy and light oxygen in marine sediments, ice cores, or fossils is different from a universally accepted standard, scientists can learn something about climate changes that have occurred in the past.
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What is albedo? Name some materials that have higher or lower albedo. |
Albedo is the fraction of solar energy (shortwave radiation) reflected from the Earth back into space. It is a measure of the reflectivity of the earth's surface. Ice has a high albedo, especially fresh snow. Water has a low albedo because it asorbs the sunlight. |
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Does water expand or contract when it freezes? |
It expands slightly until it reaches the freezing point, and then when it freezes it expands by approximately 9%. |
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Name the different types of faults, and describe the movements of the hanging wall and foot wall in each. |
Normal Faults: Drops rock on one side of the fault down relative to the other side. Has a hanging and foot wall. Hanging wall moves down, foot wall moves up. Reverse Faults: Movement is the reverse of normal faults. Hanging wall moves up, and the foot wall moves down. Strike-Slip Faults: Move away from each other in a horizontal parallel fashion. |
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How do caverns form? |
Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves. |
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What are gaining and losing streams, and how do they differ? |
Gaining stream: The channel bottom is lower than the level of the surrounding groundwater table. Through the course of the summer, water moves from the ground into the channel. Losing stream: Is above the groundwater table, and water moves from the channel into the surrounding ground. |
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What are the major types of plate boundaries, and how do they work? |
Divergent: Occurs when two tectonic plates move away from each other. Along the boundary, lava spews and there are frequent earthquakes. New crust is created here. Convergent: Two plates coming together, the collision of which causes one or both plates to lift, and one to subduct. This is what creates mountain ranges, and often a chain of volcanoes will be found parallel to the boundary. Continental crust is created, and oceanic crust is destroyed. Transform: Two plates sliding past each other forms a transform plate boundary. Man made structures that are created on these boundaries are often destroyed with the movements of the plates. No crust is created or destroyed. |
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How do base level and longitudinal profiles work in streams? |
Base Level: A stream can cut down no lower than the base level, it is the lowest point. Longitudinal Profile: A cross section of a stream from its mouth to its head, showing elevation versus distance to the mouth. Head is where the stream begins while the mouth is where it joins either into the sea or flows into a bigger river. |
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Be able to diagram the rock cycle and all the intermediary steps. |
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Diagram where and why artesian springs form. |
Water forms underground, it flows downstream in a confined aquifer. Water may then pass upwards through permeable rock out of a flowing artesian well. |
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Draw the different types of dunes, especially in relation to wind direction. |
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Cross-Bedding |
The beds are inclined in the direction that the wind or water was moving at the time of deposition. |
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Graded-Bedding |
As current velocity decreases the larger or more dense particles are deposited first, followed by smaller particles. This results in showing a decrease in grain size from top to bottom. |
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Ripple Marks |
Are characteristics of shallow water deposition, they are caused by waves or winds pulling up the sediments into long ridges. |
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Mud Cracks |
These structures result from the drawing out of wet sediments at the surface of earth. The cracks form due to shrinkage of sediments as it dries. |
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Diagram where and how different types of moraines form. |
Moraines are accumulations of dirt and rocks that have fallen onto the glacier surface or have been pushed along by the glacier as it moves. The dirt and rocks composing. Moraines can range in size from powdery silt to large rocks and boulders. |
