Geology Final Exam

During the Pleistocene Epoch, how many glacial/interglacial episodes are suspected and what is the evidence for this?

-The last glaciation ended about 11,000 years ago. But the period between 11,000 years ago and 2 million years ago (the Pleistocene Epoch) was a time of many glacial and interglacial ages -Based on evidence from glacial deposits and glacial erosion features geologists have been able to document at least 4 glaciations during the Pleistocene, two of which are poorly documented. But recent studies of deep-sea sediments and dating of these deposits suggest that there were at least 30 glaciations that occurred during the Pleistocene. This evidence comes from studies of fossils found in deep-sea sediment cores, and what they tell us about ocean surf temperatures in the past

What is the water table?

-The top of the saturated zone of groundwater -The level to which water will rise in a hole -The level to which water will rise in an unconfined aquifer

How do mass movement processes differ in deserts and more humid areas and what result do these differences have on the landscape of the areas?

-deserts: dominated by rock falls, rock slides, and the accumulation of coarse-grained material, and generally have steeper slopes. -humid regions: have soil and fine-grained regolith covering slopes, with creep being the dominant mass movement process, resulting in curved gentle slopes.

What is loess?

Large deposits of wind deposited dust.

What factors can cause long term an short term variations in climate that may be responsible for the glacial/interglacial cycles.

Long term: In climate (tens of millions of years) on a single continent are likely caused by drifting continents. If a continent drifts toward the equator, the climate will become warmer. if the continent drifts towards the poles, glaciations can occur on that continent. Short term: Climate are likely controlled by the amount of solar radiation reaching the Earth. Among these are astronomical factors and atmospheric factors.

What is deflation?

Lowering of the land surface due to removal of fine-grained particles by the wind.

Estuary

River valleys flooded by marine water.

In the unsaturated zone, pore spaces in the soil and rock contain

air and water

The Milankovitch cycles are dependent on the Earth's ________.

all of the above

What is a cutbank?

erosion

What is ventifact?

Any bedrock surface or stone that has been abraded or shaped by wind-blown sediment in a process similar to sand.

What causes the tides?

gravity

Which of the following represents the boundary between the saturated zone and the unsaturated zone?

groundwater table

Which of the following combinations make for the best groundwater reservoir?

high permeability and high porosity

The process by which surface water becomes groundwater is called

infiltration

Geysers have ____________ than regular hot springs.

more irregular plumbing systems

In the map of a stream, the arrow is pointing to a(n) ____________. (look at word doc)

oxbow lake

Wave refraction

the bending of waves so that they move nearly parallel to the shoreline

Continental slope

the slope between the outer edge of the continental shelf and the deep ocean floor.

The release of water vapor from plants is called

transpiration

Marine terraces

uplifted wave-cut platforms

Wave cut benches

wave erosion causes migration of cliff face inland

Horizontal, planar, rocky surfaces that form in the surf zone as a result of wave erosion are called ______.

wave-cut terraces

Chimney

where the height of the feature exceeds their top surface

What is the probability of a flood?

-10-year flood occurs 10% probability every year -100-year flood occurs 1% probability every year -P=1/T

Fjord

-A long narrow inlet from the sea between steep cliffs or hills -Flooded U-shaped valleys

What is the vadose zone/zone of aeration/zone of unsaturation?

-The unsaturated area above the water table -a subsurface zone in which rock openings are generally unsaturated and filled partly with air and partly with water, above the saturated zone

Describe the various types of ice laid deposits.

-Till: non-sorted glacial drift deposited directly from ice. Consists of a random mixture of different sized fragments of angular rocks in a matrix of fine-grained, sand to clay-sized fragments that were produced by abrasion within a glacier. This fine-grained material is often called rock flour because it is really ground up rock. It has undergone diagenesis and has turned into a rock is called a tillite. -Erratics: a glacially deposited rock or fragment that now rests on a surface made of different rock. Often found many kilometers from their source and by mapping the distribution pattern of erratics geologists can often determine the flow directions of the ice that carried them to their present locations. -Moraines: deposits of till that have a form different from the underlying bedrock. Depending on where it formed in relation to the glacier mountains can be: -Ground Moraines: deposited beneath the glacier and result in a hummocky topography with lots of enclosed small basins -End Moraines and Terminal Moraines: deposited at the low elevation end of a glacier as the ice retreats due to ablation (melting). It is notable that Long Island, NY and part of Cape Cod, MA are terminal moraines from the last glaciation -Lateral Moraines: deposits of till that were deposited along the sides of mountain glaciers -Medial Moraines: When two valley glaciers meet to form a larger glacier, the rock debris along the sides of both glaciers merge to form a medial moraine. These black streaks in an active glacier, as well as the deposits left behind after the ice melts. -Glacial Marine Drift: Glaciers that reach the oceans or even lakes, may calve off into large icebergs which then float on the water surface until they melt. Upon melting, the rock debris that they contain becomes immediately deposited on the sea floor or lake bed as an unsorted chaotic deposit. Sometimes single large rock fragments fall out on the floor of the water body, and these are called dropstones. -Stratified Drift: Glacial drift can be picked up and moved by meltwater streams which can then deposit that material. -Outwash plains: streams running off the end of a melting glacier are usually choked with sediment and form braided streams, which deposit poorly sorted stratified sediment in an outwash plain. These deposits are often referred to as outwash. -Kettle Lakes: If depressions form underneath a glacier and remain after the glacier is melted then water filling these depressions become small lakes where fine-grained sediment is deposited. The state of Minnesota is called the land of ten thousand lakes (mostly kettle lakes) -Kames and Kame Terraces: Streams and lakes forming on top of or on the sides of stagnant ice may deposit stratified sediment deposited by streams than ran under or within a glacier. The sediment deposited by these streams becomes an esker after the ice has melted. -Eskers: Long sinuous ridges of sediment deposited by streams than ran under or within a glacier. The sediment deposited by these streams becomes an esker after the ice has melted. -Meltwater Lakes: Depressions created by glacial erosion and deposition collect water released by melting glaciers. Sediment that collects in the bottom on the lakes is often finely layered with coarser grained layers forming during times of warmer temperatures and fine grained layers during cold times when no new sediment is entering the lake. Such finely layered strata are termed varves.

What are the 5 types of sand dunes and what are the conditions necessary to form each?

1. Barchan: they form in areas where there is a hard ground surface, a moderate supply of sand, and a constant wind direction. 2. Transverse: form in areas where there is abundant supply of sand and a constant wind direction. 3. Longitudinal: form in areas with a limited sand supply and converging wind directions. 4. Parabolic: occur where there is abundant vegetation, a constant wind direction, and abundant sand supply. They are common in coastal areas. 5. Star: form in areas where there is abundant sand and variable wind directions.

During the Pleistocene, how did the concentrations of carbon dioxide, methane, and dust vary with temperature?

Similarly, during past interglacial episodes, the atmosphere contained less dust, higher concentrations of greenhouse gases, and the Earth had a lower albedo, all of which contribute to warmer climates.

Butte

Small-topped hills that become isolated from the mesas.

What is playa lake?

Standing bodies of water like lakes are rare in desert regions because rainfall and input from streams occurs only intermittently. Lakes that do form during the rare periods of rainfall, quickly evaporate, leaving a dry lake bed behind.

What is yardang?

Streamlined wind-eroded ridges commonly found in deserts.

Which of the following best explains why the Sahara desert of Africa exists?

The Sahara desert lies near 30°N latitude

What is permeability?

The capacity of a rock to transmit a fluid such as water or petroleum through pores and fractures.

What is a drainage basin?

The entire region drained by a stream.

Which of the following statements about the groundwater table is true?

The groundwater table has the same general shape as the topography.

What is the longshore drift?

The movement of sediment along the coast by wave action.

What is meant by a recurrence interval? How is it calculated?

The number is years in the record divided by the number of events: T=N/n

What is porosity?

The percentage of rock or sediment that consists of voids or openings.

What is the difference between the saturated and unsaturated zones of groundwater?

The pore spaces in the saturated zone are full of water; the pore spaces in the unsaturated zone are not full of water.

How does a confined aquifer differ from an unconfined aquifer?

Unconfined Aquifer: the permeable layer extends to the surface. It consists of an unsaturated zone separated from the saturated zone by the groundwater table -a partially filed with aquifer exposed to the land surface and marked by a rising and falling water table Confined Aquifer: the permeable layer is overlain and underlain by a less permeable layer (aquiclude) -an aquifer completely filled with pressurized water and separated from the land surface by a relatively impermeable confining bed, such as shale

In the temperate zones of the Earth between 30° and 60° latitude, the prevailing winds come from the ______.

West

How does glaciation modify the landscape in terms of drainage networks and lakes?

When glacial forms, it can block existing drainages causing the formation of new lakes and forcing streams to find new pathways that develop into new drainage networks. Once the ice melts, the new drainage network become well established and the old drainage networks are often abandoned.

What is a desert?

Where rainfall is less than 250mm (10in) or where evaporation exceeds precipitation.

For a given river, which of the following floods would have the largest discharge?

a 50-year flood

How fast does most groundwater move in aquifers?

a few centimeters per day

Which of the following would be the most fertile area for crops?

a floodplain

Atoll

a ringlike coral island or string of small islands surrounding a lagoon

Which of the following sandstones will have the highest porosity?

a well-sorted, uncemented sandstone

Permeability is the

ability of a solid to allow fluids to pass through.

Which of the following features can be used to determine the direction a continental glacier moved?

all of the above

Which of the following is a depositional feature rather than an erosional feature?

an esker

Groundwater represents how much of the world's fresh water?

approximately 29%

If the Earth's atmosphere did not contain greenhouse gases, the Earth's surface would be __________.

approximately 33°C cooler

Layers that transmit groundwater are called

aquifers

In which of the following locations would one most likely find a braided stream?

at the edge of a melting glacier

Which of the following forms a barricade between the open ocean and the main shoreline?

barrier islands

Which of the following types of streams has many channels?

braided streams

Near-shore crest-shaped waves are called __________.

breakers

Wave base

1/2 wavelength

In Hawaii, the difference between low and high tides is approximately 0.5 m. In the Bay of Fundy in eastern Canada, the tidal range can reach __________.

12 m

At the last glacial maximum, sea level was about ______ lower than today.

130 m

What is the probability of a 50-year flood occurring next year along the Skykomish River in Washington State?

2%

Which of the following statements regarding floods is true?

A 50-year flood has a 2% chance of occurring in any one year.

Active continental margin

A continental margin where the continent coincides with a convergent plate boundary.

What is desert varnish?

A dark reddish-brown surface coating of iron and manganese

Alluvial fan

A fan-shaped deposit of sediment formed when a stream's slope is abruptly reduced -forms where a mountain stream enters a broad flat valley and deposits sediment as its velocity decreases on entering the flatter valley

Continental shelf

A gently sloping, shallow area of the ocean floor that extends outward from the edge of a continent.

Salinity

A measure of the amount of dissolved ions in the oceans.

Tombolo

A spit that connects the mainland to an offshore island.

How do springs form?

A spring forms whenever the water table intersects the ground (land) surface.

What is desert pavement?

A surface composed only of the coarser grained fragments that cannot be transported by the wind.

What is an 'artesian well'?

A well in which water rises above the aquifer.

What is a stream?

Any body of water, confined to a channel that flows downhill under their influence of gravity.

What is an aquifer? An aquiclude? An aquitard?

Aquifer: A body of saturated rock or sediment through which water can move easily -include sandstone, conglomerate, well-joined limestone, bodies of sand and gravel, and some fragmental or fractured volcanic rocks such as columnar basalt -geologic unit capable of storing and transmitting water in sufficient quantities to supply wells. Has high porosity and permeability Aquitards: When a porosity of a rock is 1% or less and therefore retards the flow of groundwater Aquiclude: A geologic unit that resists water flow (relative to aquitard). Has low porosity and permeability -another name for aquitard if completely impermeable

Why is Minnesota called the Land of Ten Thousand Lakes?

Because the large amount of kettle lakes.

Explain how sand dunes can migrate across the surface?

Dunes migrate by the erosion of sand by wind (saltation) on the gentle upwind slope, and deposition and sliding on the slip face, and thus are cross-bedded.

From what direction do the trade winds in the tropics blow?

East

Which of the following statements regarding effluent streams is true?

Effluent streams are fed by groundwater and are characteristic of humid regions.

The anomalous warming of the eastern Pacific Ocean that occurs every 3 to 7 years is called ________.

El Niño

Spit

Elongated deposits of sand or gravel that projects from the land into open Spits usually form at the mouth of a bay due to long shore current and beach drift.

What are the ways to prevent floods? What are the pros and cons of each?

Engineer Approach: Channel modifications, Dams, Retention ponds, Levees, Floodways Regulatory Approach: Floodplain zoning, Floodpain building codes, Floodpain buyout programs, Mortgage limitations

What term is used to indicate a geologic process powered by wind?

Eolian

How is water withdrawn from the subsurface?

FRACKING By drilling up a well and pumping the water out: - Water in the well, rises to the top of the water table - Water beneath the surface moves slowly (a few cm/m per day) depending on the permeability - If water is extracted too fast, the water table will drop locally around the well called the "cone of depression"

Mesa

Flat-topped hills

How does a floodplain develop?

Form on either side of a river, produced when a river floods onto when experiencing high discharge.

What effect do greenhouses gasses have on solar radiation?

Greenhouse gases in the atmosphere absorb some of the longer wavelength (infrared) radiation and keep some of it in the atmosphere. This keeps the atmospheric temperature relatively stable so long as the concentration of greenhouse gases remains relatively stable, and thus, the greenhouse gases are necessary for life to exist on Earth.

What are the geologic processes that occur in the headwaters? Body or trunk? Mouth?

Headwater: -Headward erosion—process that lengthens the stream, a valley or a gully at its beginning and also enlarges the drainage basin Middle/Trunk: -Strike a balance between erosion and deposition -Stream begins to meander back and forth cutting a wide flood plain Lower/Mouth: -As the gradient decreases, it is dominated by depositional processes.

Which of the following statements regarding porosity and permeability is true?

High porosity rocks generally have high permeability.

What are some of the effects of excessive groundwater withdrawal?

If groundwater is withdrawn faster than it is being recharged, however, the supply is being reduced and will one day be gone 1) Heavy use of ground water can result in: -a regional water table dropping -deepening of a well which means more electricity is needed to pump the water to the surface -the ground surface settling because the water no longer support the rock and sediment -to avoid the problems of falling water tables, subsidence, and compaction, many towns use artificial recharge to increase recharge; natural floodwaters or treated industrial or domestic wastewaters are stored in infiltration ponds in the surface to increase the rate of water percolation into the ground.

Sea arches

If sea caves from opposite sides of a rocky headland meet.

Which of the following statements is true?

Influent streams recharge groundwater and are characteristic of arid regions.

What is a floodplain?

Large, flat expanses of land that form on either side of a river.

What are the main characteristics of beaches in terms of sediment type, sediment composition, and sedimentary structures?

May be coarse or fine grained sediment -Boulders from local cliffs -Sand from rivers -Mud from rivers -Quartz is most common

What is the evidence that global warming has taken place since the mid 1800s and that humans are responsible for the warming?

Models and charts. -Humans have contributed through domestication of animals, increased production of rice, and leaks from gas pipelines and gasoline. -The CO2 concentration in the atmosphere has been increasing since the mid 1800s. The increase correlates well with burning of fossil fuels. Thus, humans appear to have an effect.

Passive continental margin

Occurs in the interior of plate, far away from any plate boundary.

How does wave energy effect these?

Particles picked up by wave motion move down slope, but the deeper the water, the less energy is involved in wave motion, so smaller and smaller particles are moved farther off shore. This results in size sorting of sediment, with grain size decreasing away from

________ is the infiltration of water into the saturated zone, and _______ is the exit of groundwater to the surface.

Recharge; discharge

Which of the following statements about groundwater in coastal regions is true?

Seawater is denser than fresh water; therefore, fresh groundwater floats on top of salty groundwater.

What are the characteristics of sediment deposited directly from glaciers?

Sediments deposited directly from melting of a glacial can range from very poorly sorted to better sorted, depending on how much water transport takes place after ice melts.

What powers the hydrologic cycle?

solar energy

The word _____ is used for any flowing body of water large or small.

stream

Which of the following terms describes the region of breaking waves near the shoreline?

surf zone

A glacier is receding if __________.

the amount of ablation exceeds the amount of accumulation.

After oceans, which of the following reservoirs contains the most water?

the glaciers and polar ice caps

Abyssal plain

very level area of the deep-ocean floor, usually lying at the foot of the continental rise.

Chemical analysis of ice cores demonstrates that as temperature increases, concentrations of atmospheric __________.

carbon dioxide and methane both increase

Desert varnish is composed of all of the following except __________.

carbonate minerals

Bajadas

coalesced alluvial fans

Sea Stack

column of rock remaining after the collapse of a sea arch

What type of aquifer is bounded above and below by relatively impermeable beds?

confined

Where does a stream channel begin?

where rainwater flows over the surface so fast that it carves into the underlying units

If the amount of discharge in an aquifer exceeds the amount of recharge, the groundwater table

will drop

What are the main factors responsible for oceanic circulation?

density, temperature, salinity

What is a pointbar?

deposition

The velocity of a river multiplied by the cross-sectional area of the river channel yields the river's

discharge

The volume of water flowing past a given point in a given time is called the ______.

discharge

A ridge of high land between two streams is called a

divide

Sea caves

formed by wave action undercutting and forming an opening at the base of a sea cliff

The largest freshwater reservoir in the hydrologic cycle is

glaciers

The main force that drives glacial flow is ___________.

gravity

Which of the following forces is the dominant cause of mass movement?

gravity

For most rivers, discharge __________ downstream.

increases

What minerals are responsible for the orange-brown colors of weathered surfaces in the desert?

iron oxides

What is the major consumer of groundwater?

irrigation

Which of the following is not a cause of desertification?

irrigation

Inselbergs

isolated, steep-sided erosional remnants that rise above desert plains. -A small, rounded hill, knob, ridge, or mini mountain that rises abruptly from relatively flat surroundings.

The best way to preserve natural beach environments is to ___________.

leave it alone

In what type of rock do most caves form?

limestone

Sinkholes are a possible danger in regions underlain by what type of bedrock?

limestone

The zigzag motion that carries sand grains along a beach is known as ________.

longshore drift

Oxbow lakes are associated with which of the following types of rivers?

meandering rivers

Curves and bends in a stream channel are called ______.

meanders

Which of the following terms describes an accumulation of rocky, sandy, or clayey material deposited at the end of a glacier?

moraine

Wave-cut cliffs

originate in the cutting action of the surf against the base of coastal land (erosion).

A rip current is a strong flow of water moving _______.

perpendicular to the shore

Which of the following is not caused by overpumping groundwater?

raising of the land surface

Most of the world's deserts occur in the ________.

regions north and south of the equator, known as the tropics

The main difference between a hot spring and a geyser lies in the

regularity of the underground plumbing system.

Which of the following unfractured rocks has the highest porosity?

sandstone

Which of the following is not a shoreline depositional landform?

sea stack

The steeper, downwind side of a sand dune is called a

slip face

What are the pros and cons of each prevention?

-Channel modifications - By creating new channels for a stream, the cross-sectional area can be enlarged, thus creating a situation where a higher stage is necessary before flooding. Channelization also increases water velocity, and thus reduces drainage time. -Dams - Dams can be used to hold water back so that discharge downstream can be regulated at the desired rate. Human constructed dams have spillways that can be opened to reduce the level of water in the reservoir behind the dam. Thus, the water level can be lowered prior to heavy rain, and more water can be trapped in the reservoir and released later at a controlled discharge. -Retention ponds - Retention ponds serve a similar purpose to dams. Water can be trapped in a retention pond and then released at a controlled discharge to prevent flooding downstream. -Levees, Dikes, and Floodwalls - These are structures built alongside the channel to increase the stage at which the stream floods. -Floodways - Floodways are areas that can be built to provide an outlet to a stream and allow it to flood into an area that has been designated as a floodway. Floodways are areas where no construction is allowed, and where the land is used for agricultural or recreational purposes when there is no threat of a flood, but which provide an outlet for floodwaters during periods of high discharge. The Bonnet Carrie Spillway west of New Orleans is such a floodway. During low stages of the Mississippi River the land between the River and Lake Pontchartrain is used for recreational purposes - hunting, fishing, and dirt bike riding for example. During high stages of the River when there is a potential for the River to rise to flood stage in New Orleans, the spillway is opened so that water drains into Lake Pontchartrain. This lowers the level of water in the Mississippi and reduces the possibility of a levee break or water overtopping the levee. -Floodplain zoning - Laws can be passed that restrict construction and habitation of floodplains. Instead, floodplains can be zoned for agricultural use, recreation, or other uses wherein lives and property are not endangered when (note that I did not use the word if) floodwaters re-occupy the floodplain. - Floodplain building codes - Structures that are allowed within the floodplain could be restricted to those that can withstand the high velocity of floodwaters and are high enough off the ground to reduce the risk of contact with water. -Floodplain buyout programs - In areas that have been recently flooded, it may be more cost-effective for the government, which usually pays for flood damage either through subsidized flood insurance or direct disaster relief, to buy the rights to the land rather than pay the cost of reconstruction and then have to pay again the next time the river floods. -Mortgage limitations - Lending institutions could refuse to give loans to buy or construct dwellings or businesses in flood-prone areas.

Describe the different types of mountain glaciers.

-Cirque: bowl-shaped depressions on sides of mountains -Valley: As cirque glaciers grow larger they may spread into valleys and flow down the valleys -Fjord: valley glacier extends down to sea level, it may carve a narrow valley into the coastline -Piedmont: f a valley glacier extends down a valley and then covers a gentle slope beyond the mountain range -(Ice Sheets) Continental: are the largest types of glaciers on Earth. They cover large areas of the land surface, including mountain areas. -Temperate: Ice in a temperate glacier is at a temperature near its melting -Polar: Ice in a polar glacier always maintains a temperature well below its melting point. -Ice Caps: If all of the valleys in a mountain range become filled with glaciers, and the glaciers cover then entire mountain range

How do caves form?

-Develop when slightly acidic groundwater dissolves limestone along joints and bedding planes, opening up cavern systems as calcite is carried away in solution -Formed by groundwater circulating below the water table

How is geothermal energy produced?

-Electricity can be generated by harnessing naturally occurring stream and hot water in areas that are exceptionally hot underground

What are emergent coasts and submergent coasts, what causes each to form, and what are the characteristic of each?

-Emergent coasts: result from local tectonic or isostatic uplift or from a drop in eustatic sea level. Characterized by rocky coasts with sea cliffs and raised wave cut benches (marine terraces). -Submergent coasts: result from either subsidence along the coast due to tectonic forces or eustatic sea level rise. Characterized by gentle shorelines, flooded river valleys (estuaries and fjords), and barrier islands.

What is the cause of flooding?

-Flood occur when the discharge of the stream becomes too high to be accommodated in the normal stream channel. -Other Possible Causes: 1. Heavy rains dump large volumes of water on the landscape increasing the amount of water flowing into the 2. If the soil has become saturated as a result of rain so that there is no room in the soil for water to infiltrate, the water instead will run into stream channels and increase the discharge. 3. In the winter, if a sudden increase in temperature rapidly melts snow causing an influx of water into the drainage system. 4. When a natural or artificial dam breaks or levee breaks, releasing water into a channel with a sudden increase in discharge or releases water from the channel onto the surrounding floodplain.

How are geysers and hot springs formed?

-Geysers form when hot water erupts to the surface. They are caused by boiling of the water at depth which causes vapor bubbles to rise and reduce the pressure. -Hot springs: (1) where deep groundwater surfaces along faults or fractures (2) in geothermal regions where groundwater is heated by shallow magma or hot rock.

What are the 5 types of deserts that occur on earth?

-Subtropical -Rain Shadow -Coastal -Continental -Polar

What are the main changes to be expected from global warming?

-Global Precipitation changes - A warmer atmosphere will lead to increased evaporation from surface waters and result in higher amounts of The equatorial regions will be wetter than present, while the interior portions of continents will become warmer and drier than present. -Changes in vegetation patterns - because rainfall will distributed differently, vegetation will have to adjust to the new conditions. Mid latitude regions are likely to be more drought-prone, while higher latitude regions will be somewhat wetter and warmer than normal, resulting in a shift in agricultural patterns. -Increased storminess - A warmer, wetter atmosphere will favor tropical storm development. Hurricanes will be stronger and more frequent. -Changes in Ice patterns. - Due to higher temperatures, ice in mountain glaciers will melt. This is now being observed. But, because more water will be evaporated from the oceans, more precipitation will reach the polar ice sheets causing them to grow. -Reduction of sea ice - Sea ice will be greatly reduced to the increased temperatures at the high latitudes, particularly in the northern hemisphere where there is more abundant sea ice. This is now being observed. -Thawing of frozen ground - Currently much of the ground at high latitudes remains frozen all year. Increased temperatures will cause much of this ground to thaw. Organic compounds and gas hydrates in the frozen ground will be subject to decay, releasing more methane into the atmosphere and enhancing the greenhouse effect. Ecosystems and human structures currently built on frozen ground will have to adjust. -Rise of sea level - Warming the oceans results in expansion of water and thus increases the volume of water in the oceans. Along with melting of mountain glaciers and reduction in sea ice, this will cause sea level to rise and flood coastal zones, where much of the world's population currently resides. -Changes in the hydrologic cycle - With new patterns of precipitation changes in stream flow and groundwater level will be expected. -Decomposition of organic matter in soil - With increasing temperatures of the atmosphere the rate of decay of organic material in soils will be greatly accelerated. This will result in release of CO2 and methane into the atmosphere and enhance the greenhouse effect. -Breakdown of gas hydrates - This is basically solid water with gas molecules like methane locked into the crystal structure. They occur in oceanic sediments and beneath frozen ground at high latitudes. Warming of the oceans or warming of the soil at high altitudes could cause melting of the gas hydrates which would release methane into the atmosphere. Since methane is a greenhouse gas, this would cause further global warming.

Cuesta

-If the cliff-forming rocks have bedding planes that dip, then an asymmetrical ridge -The steep cliff forms on one side and a gentle slope parallel to the bedding planes forms on the other side.

Why were mid-Cretaceous and Eocene climates so warm?

-Large volcanic plateaus were emplaced in the ocean basins -The increased CO2 concentrations have been attributed to a large scale metamorphic event that occurred as a result of the continent-continent collision

Explain how longshore current and beach drift operates along a coast

-Longshore current: Since most waves arrive at the shoreline at an angle even after refraction. Such waves have a velocity oriented in the direction perpendicular to the wave crests (Vw), but this velocity can be resolved into a component perpendicular to the shore (Vp) and a component parallel to the shore (VL). -Beach drift: due to waves approaching at angles to the beach, but retreating perpendicular to the shoreline. This results in the swash of the incoming wave moving the sand up the beach in a direction perpendicular to the incoming wave crests and the backwash moving the sand down the beach perpendicular to the shoreline. Thus, with successive waves, the sand will move along a zigzag path.

What are losing streams and gaining streams? Influent/Effluent?

-Losing stream: a stream that loses water to the zone of saturation -Gaining stream: a stream that receives -Influent: a stream that recharges groundwater -Effluent: a stream which picks up water from the saturated zone

What are the greenhouse gasses and which of these is the most abundant?

-Most abundant is H20 -GG: H2O water vapor, CO2 cardo dioxide, CH4 methane, and ozone

What natural and anthropogenic (human induced) factors can result in desertification?

-Natural impacts: changing positions of the continents, changes in ocean and air circulation patterns -Human impacts: overgrazing, overpopulation, draining of land, and lowering of the groundwater table

How is water distributed on the planet?

-Oceans account for 96% of Earth's total water. -Groundwater is 22% of freshwater -Freshwater lakes and streams 0.016%

How is groundwater contaiminated?

-Sewers and septic tanks -Waste dumps (both industrial and residential) -Gasoline Tanks (like occur beneath all service stations) -Biological waste products - Biological contaminants can be removed from the groundwater by natural processes if the aquifer has interconnections between pores that are smaller than the microbes. For example, a sandy aquifer may act as a filter for biological contaminants. -Agricultural pollutants such as fertilizers and -Saltwater contamination - results from the excessive discharge of fresh groundwater in coastal areas. -Groundwater contamination can result from a point source where the contaminant plume emanates from 1 spot.

What is the saturated zone?

The subsurface zone in which all rock openings are filed with water

Which of the following best explains why the Great Basin and Mojave deserts of western North America exist?

The two deserts lie in the rain shadow of coastal mountains

What is a discharge?

The volume of water passing a given point on a stream per unit of time.

What is groundwater?

The water that lies beneath the ground surface, filling the pore space between grains in bodies of sediment and clastic sedimentary rock, and filling cracks and crevices in all types of rock.

How does water enter into the subsurface?

Through the process of infiltration which is dependent on porosity and permeability

In geology, the term stream is applied to any body of water flowing over the surface, regardless of the size of that body of water.

True