Geology

Describe the work of water as it runs across the land. As water runs across the land it: ( Select all that apply.)

(everything except landslides)

During a flood, excess water flows outside of the channel on the adjoining land, which is known as the

Floodplain

The location where a stream stores excess water and sediment during a flood is called a

Floodplain

Describe how crustal uplift can affect the evolution of a fluvial landscape. Crustal uplift will increase the gradient of a drainage basin and lead to stream

Rejuvenation

________ is the type of sediment that is the easiest to erode.

Sand

Which types of sediment(s) require nearly as much water velocity to keep them in motion as is required to erode the grains in the first place?

Sand and Gravel

When headward erosion breaches a drainage divide, intersects another channel, and captures its flow, this is called

Stream piracy

Karst is a geological feature that occurs when groundwater dissolves:

carbonATE rock

Which of the following contributes to desert pavement when found in excessive amounts?

lag deposit

What are the most common ways to recharge groundwater? Groundwater is recharged by: (Select all that apply.)

lakes, streams, wetlands, rainfall

wind is _____ than water

less

What is the density difference between gasoline and water? Where is gasoline likely to collect in an aquifer? Gasoline is ________

less dense

What percentage of streams in the United States are fed by groundwater discharge?

30

The relationship between the number of stream segments in one order and the next is consistently around:

3:1

Water covers how much of the Earth's surface?

71%

What percentage of US freshwater is supplied by water wells?

95

What is another name for a drapery formation in a cave?

A curtain

Which of these sediments has the highest porosity? Which has the highest permeability?

A, A

Which of the following is not one of the unusual features caused by the dissolution process?

ALL ARE

What causes avulsion? Avulsion occurs where a stream _______ its channel and finds a new, more efficient path to base level.

Abandons

______ involves injecting gas (usually air or oxygen) into the saturated zone in order to mobilize contaminants that are volatile or easily stirred into a gaseous phase.

Airsparging

A stream carries a sediment load that may be transported as two types of loads known as

Alluvial Load & Suspended Load

_______ develop(s) when a graded stream incises its floodplain.

Alluvial terraces

a ______ is an underground formation of saturated crust that can produce useful quantities of water when tapped with a well.

Aquifer

Which method of groundwater remediation involves increasing permeability of rock?

Aquifer fracturing

The process that occurs when a flood that has swept down the river arrives at the flat delta plain, overflows its banks, and establishes a new route to the sea is called:

Avulsion

Why is clay difficult to erode but easy to transport?

Because clay sticks to the channel bed but stays in suspension once it has been eroded.

As a field geologist in the area of panel (c), what evidence would convince you that the area once had a waterfall? Evidence would include the presence of

Boulders

Watersheds are shaped roughly like:

Bowls

Well developed permeability channels that form when diffuse-flow aquifers are transformed in conduit-flow aquifers are called?

Conduit systems

What is the difference between a delta and an alluvial fan? Alluvial fans and deltas have similar features ________ from where a stream reaches its base level.

Deltas, Alluvial

Describe how the density of a pollutant governs its role in contaminating groundwater. If a pollutant is denser than water it tends to sink to the bottom of an aquifer; if it is less dense than water it tends to float on top of an aquifer. The

Density

The volume of water (per unit of time) passing any point on a stream is called the

Discharge

________ consists of ions that have entered the water as a result of chemical weathering of rocks.

Dissolved Load

What is the chemical composition of these features? How do they form? Speleothems are usually composed of calcium carbonate that is inorganically precipitated from a dissolved state in groundwater. Precipitation is normally caused by

Evaporation

Increasing the gradient will usually produce a graded stream that successfully transports all the available sediment and does not erode the bed.

FALSE

After a property has been developed with buildings and the land surface paved, the hydrologic character of the runoff stays the same.

False

Clay is relatively easy to erode.

False

How might Darcy's law be useful in planning a program of groundwater conservation? Groundwater can be conserved by removing it at a rate that is more than the rate at which it is discharged. Darcy's Law defines groundwater recharge and provides an estimate of the rate that it can be conserved.

False

Meandering streams are characterized by highly variable discharge, easily eroded banks, and excessive sediment.

False

Most springs are formed in places where the water table is directed away from the surface by the structures of rock layers that contain groundwater.

False

Much of Earth's landscape is the product of erosion caused by wind.

False

Suspended load consists of large particles that remain on the stream bed for most of the time that they are moved by the water.

False

The stream below a dam will experience an decrease in velocity.

False

A stream with no tributaries is known as a:

First-order stream

In arid climates where heavy rains come suddenly, _______ flooding is likely to occur.

Flash

_______ can happen when there are elevated levels of storm water runoff in an arid landscape.

Flash floods

______ originate when hot water in the geyser's plumbing system mixes with cooler water from the surface.

Geysers

What keeps water moving through the hydrologic cycle? Select all that apply.

Gravity, sun, precipitation

Karst formation results from the dissolution of carbon dioxide into

Groundwater

Groundwater that contains high levels of dissolved minerals and often leaves a coating of mineral precipitants on plumbing fixtures is known as

Hard water

What is the name of the diagram that plots the relationship between water velocity and sediment size?

Hjulstorm

The difference in elevation between two points in an aquifer divided by their distance is known as

Hydraulic gradient

Which is true of a sand sea?

It contains many large sand dunes and sand covers more than 20% of the ground surface.

Which of the following is not a characteristic of the Basin and Range Province?

It is an extremely moist desert region.

Water flowing within a channel may be either ______ in which all water molecules travel along parallel and uniform flow paths, or , _____ in which individual water molecules follow irregular paths.

Laminar, Turbulent

Excavations in the ground that are meant to hold waste generated by a community are called

Landfills

Which type of cave is related to the karst process?

Limestone

What is the most extensive cave in the world?

Mammoth

_________ channels are the most common characteristic of a stream that is free to roam across a valley floor.

Meandering

Examples of stream movement that leads to high levels of sediment production do not include:

Meandering Channels

_______ is sometimes seen as "walking away from the problem" of groundwater pollution.

Natural attenuation

What is the effect of momentum on water flow? Momentum keeps water moving in a straight line until some force turns it. This causes erosion on the

Outer

When a meandering stream grows too sinuous so that it is no longer efficient, the stream will find a more direct path from one curve of the stream to the next, cutting off one curve. The body of water formed by the curve that is no longer part of the stream channel is called a(n):

Oxbow lake

_______ is the measure of the ability of rock or sediment to transmit groundwater.

Permeability

______ are closed basins that replace stream valleys and divert surface drainage underground.

Sinkholes

Describe the research program that must have been conducted in order to develop the Hjulstrom diagram. A researcher must have measured the velocity of stream flow that eroded many different

Sizes

Explain why groundwater in karst is highly vulnerable to contamination. Because karst systems are characterized by conduit flow aquifers where water flows rapidly, pollutants enter the system quickly,

Spread

_______ forms from the ceiling of when water drips down through cracks in the cave roof?

Stalactite

What happens when the water table is located beneath the base of a channel?

The channel becomes an effluent stream

Which is not a characteristic of a trade wind desert?

The desert atmosphere accumulates cloud masses.

An artesian aquifer has an internal pressure because of the confining bed that prevents water flow. This pressure is a result of:

The recharge area being at a higher lever than the rest of the aquifer

Which is not a characteristic of crescentic dunes?

The steep slip face is on the convex side of the dune.

Why do the winds at midlatitude deserts tend to be westerlies?

The winds originate at the boundary of the Hadley and Ferrel cells, flow toward the north, and are deflected by the Coriolis effect.

What is unique about the Nile and Colorado rivers that enable them to exist as large desert rivers?

They originate outside of a desert environment and they start in mountains with heavy snow or rainfall.

Braided channels are formed when a stream contains more sediment than it can readily transport.

True

Drainage patterns depend on the nature of the underlying geology.

True

Due to low rainfall, permanent streams are very rare in desert environments.

True

Every point on Earth's surface is part of a watershed.

True

It takes less velocity to keep sediments moving than it does to erode them in the first place.

True

The average velocity of laminar flow is generally greater than turbulent flow.

True

The sediment composing an alluvial fan is subtly sorted so that coarse material tends to be deposited near the mouth of the fan.

True

Water is the dominant agent governing environmental processes.

True

When runoff flows away from a dome or hilltop in all directions it is called radial drainage:

True

Which pathways do water particles follow in turbulent flow? In turbulent flow water particles generally flow downhill but there is locally chaotic water movement in which particles flow against the mean flow direction.

True

Why is flooding described as a "wave"? Stream discharge goes from normal to high and back to normal again as a flood passes. This shape on a graph looks like a wave, and flood comes and goes like a wave with a front, peak, and back.

True

________ flow can keep sediment suspended in the water column longer than ________ flow can, and it increases erosion of the stream bottom and channel walls.

Turbulent, laminar

Porous media in which the grains are not connected to one another are called

Unconsolidated

Two types of erosion that create a valley are

Undercutting and Mass wasting

Waterfalls migrate _________ as resistant rock ledges are eroded:

Upstream

What is the correct formula for the velocity of groundwater flow?

V = K (h2 - h1) / L

The total area feeding water to a stream is called the:

Watershed

Over the next two decades, population growth and increasing demand for freshwater are projected to push all ______ countries into water scarcity conditions.

West Asian

Topset beds constitute the delta plain and are host to freshwater and saltwater _________ if the delta is formed in the ocean.

Wetlands

Which of the following is not one of the three ways that groundwater can interact with wetlands?

Wetlands directly affect the amount of precipitation that accumulates in the atmosphere

What forms when water trickles along the inclined ceiling of a cave?

a curtain

Significant loess deposits are found in the following areas, EXCEPT

africa

Which of the following is characteristic of the Sahel region of North Africa?

all

Which type of atmospheric cell is present in both the northern and southern hemispheres?

all

What characteristics were true of the Sahara between 5,000 and 10,000 years ago?

all are correct

What measures have been implemented nationally to mitigate the threats of desertification?

all are correct

What atmospheric characteristics are present in the formation of polar deserts?

all choices

How are permeability and porosity related to one another? Porosity is an important characteristic that may control permeability. If pores Select your answer the permeability will be high; if they

are connected, are not

What would happen to a parabolic dune if the wind direction changed and precipitation decreased? Parabolic dunes form where sand collects in the lee of vegetation. A decrease in precipitation will likely result in loss of the vegetation. This, plus a reversal in wind direction, will likely produce (Select all that apply.):

barchane, transverse

What is the relationship between regions threatened by desertification and the major deserts we studied earlier? Most areas threatened by desertification

border or lie nearby, deserts

Karst formation involves the dissolution of carbon dioxide into groundwater. Which of the following is the product of this process?

carbonic acid

Many rural and suburban homes are not connected to community sewage disposal lines. Instead they rely on what to dispose of their waste?

cesspools and septic tanks

Fractured aquifers in limestone are most typically caused by:

chemical weathering

Typically, sediments that have high permeability also have high porosity. Which of the following has high porosity, but low permeability?

clay

When cold ocean currents approach land, the heating of _______

cold air

What is a contaminant plume, and how does it move? A contaminant plume is a zone of _________

concentrated

Porous media in which the grains are cemented or compacted are called:

consolidated

Describe the field methods you would use to obtain the data necessary for calculating the discharge in a stream in your neighborhood. Discharge is calculated by collecting data on the

cross sectional, velocity

How do stream gradient and discharge change with distance downstream? Stream gradient ____

decreases, increases

How does the shape of a channel change with distance downstream? A stream channel becomes ________

deeper, wider

What is another name for a gaining stream?

effluent

When openings in bedrock increase in size, and an underground drainage system develops, it is called:

endikarst

Which is harder to erode: gravel or clay?

equally hard

How would you use the law of stream numbers to help manage streams? The Law of Stream Numbers provides a simple guide for

estimating, modeling

Agriculture accounts for 50% of pesticide use in the United States.

false

Collapsing sand comes to rest when it reaches a slope of about 60 to 64 degrees.

false

Hydroelectric dams are great sources of electricity with no downsides.

false

The Indian monsoon is a perennial rain that flows off the Indian Ocean and Arabian Sea.

false

The droughts of the 1930s enabled Utah to become an agricultural, cultural, and political powerhouse.

false

The most common dune is the barchan dune.

false

Water stress problems cannot be solved.

false

When an aquifer is overpumped, a cone of depression decreases the hydraulic gradient.

false

State a hypothesis describing water flow in a channel. Describe how you would test your hypothesis. Hypothesis: Water tends to flow

fastest, deepest

What are the important water problems where you live? An answer should describe: (Select all that apply.)

flooding, polluted, water scarcity

Which attributes are used to identify deserts through the system proposed by the U.S. Geological Survey?

geo location and weather patterns

What force drives the flow of water in the ground? Groundwater flows in response to: (Select all that apply.)

gravity and pressure

Why are stream valleys generally steeper in their upper reaches? How is this related to rainfall or topography? Headwaters are typically located where rainfall is

high, high, high

Which was not a result of the Dust Bowl of the 1930s?

houses were built to create barriers

What are the major processes in the hydrologic cycle? The hydrologic cycle consists of five major processes: (Select all that apply.)

inflitration, runoff, precipitation, condensation, evaporation

What is another name for a losing stream?

influent

What method of remediation involves treating a contaminated aquifer with chemical additives in order to strip or cleanse a specific pollutant?

injection walls

Which factor contributes to the large daily and seasonal temperature range in deserts?

low humidity

What is used in the method of bioremediation to control pollution?

microbes and plant tissue

The extreme interior location of the vast mountainous central Asian deserts contributes to their formation because ________ is lost from the air

moisture

A ______ is a season of high rainfall in the tropics.

monsoon

Develop a hypothesis that predicts the impact of building artificial levees along the Mississippi River and delta. How would this affect downstream communities, the delta region, ecosystems, and coastal waters? Hypothesis: Artificial levees impact natural processes of sedimentation. Along the Mississippi River levees cause ________

more flooding

How many water wells are drilled in the United States each year?

more than 800,000

What measure is being taken to avoid gasoline leaks?

old tanks are being replaced

How does the outer bank of a channel in a curved segment change with time? The outer bank in a meander moves

outward

Which of the following is not a result of global desertification?

ozone depletion

_______ dunes require an abundant supply of sediment and vegetation.

parabolic

What waterways are controlled entirely by rainfall and evaporation?

playa lakes

What is the result of the Coriolis effect on the northern Polar cell?

polar easterlies

Contaminated storm water runoff is referred to as:

polluted RUNOFF

Artesian springs flow because the pressure forces the water out of the ground, and it rises to a new level called:

potentiometric surface

Describe the necessary steps in developing a useful water well. A useful water well begins as a borehole that reaches below the water table. The hole is lined to keep out sediments, the walls of the well are lined with gravel, a

pump, pollution

What is the result of continued condensation across the globe?

rain and snow as well as water droplets and clouds

What forms as windblown grains begin to accumulate?

ripples and dunes

What processes are capable of causing the water table to rise and fall? The water table

rises, fall

The process by which windblown grains move short distances before falling back to the ground is known as

saltation

Which of the following is not one of the four principal types of dunes?

sand seas

If all streams were allowed to flow continuously through time, with no new uplift of the land, eventually they would carve their channels down to

sea level

Are speleothems igneous, sedimentary, or metamorphic? Explain your reasoning. Speleothems are

sedimentary

What factors influence permeability? Permeability is influenced by the

size, connected

In caves, dissolved calcium carbonate in groundwater precipitates on the floor, the roof, or the walls, creating complex "dripstone" features called:

spelothemes

Describe the factors that should be considered in making a decision to allow natural attenuation of a contaminated aquifer. Factors in a decision to allow natural attenuation include: the rate of attenuation, the Select your answer of the contaminant plume (is the plume moving?), is the plume close to sources of Select your answer or natural ecosystems?, the potential Select your answer of clean-up, possibility of disturbing the plume in the event of a massive flood or heavy rainfall event.

stability, drinking water, cost

Identify some potential consequences of an influx of environmental refugees to a village already stressed by desertification. Increased population in an area stressed by desertification can produce more __________

stress

As a consultant you are concerned about future freshwater availability for coastal towns in Florida. What data do you need to assess groundwater resources for the future? State a hypothesis you want to test. Hypothesis: Sea-level rise threatens groundwater in Florida. To assess groundwater resources the following data are needed: maps of the water table , the hydraulic gradient , all cones of depression, the location of the freshwater saltwater transition, rates of sea level rise in the future, and knowledge of whether pumping rates are

sustainable

What region acts as the border between a vast desert and moist tropical rainforests?

the Sahel region of North Africa

Which is not a characteristic of a midlatitude desert?

the rate of moisture condensation exceeds evaporation

Which method of groundwater remediation involves the injection of hot steam?

thermal and electrical treatments

Which of these are characteristics of the top two largest deserts in the world?

they are covered with ice and snow and receive very little precipitation

The interface where freshwater naturally mixes with seawater as it is discharged to the sea is called:

transition zone

An artesian aquifer is one in which water escapes to the surface, driven by the hydraulic gradient of the water table.

true

An ephemeral stream is defined as flowing water present after rainfall events, only containing water for approximately 24 to 48 hours.

true

An erg is what most people imagine when picturing a desert.

true

Coastal deserts are found on continents in both the northern and southern hemispheres.

true

Continued pumping at an excessive rate in coastal areas will cause saltwater intrusion, which damages the quality of the aquifer.

true

Dunes can form underwater in rivers from sand that is transported by running water.

true

Every continent on Earth has significant areas where desertification is an important hazard.

true

Groundwater moves very slowly through relatively impermeable materials such as clay and shale.

true

Millions of livestock and people died as a result of droughts in the Sahel region of North Africa.

true

Natural springs are places where the water table intersects with the Earth's surface and water flows on the land.

true

On April 14, 1935, the worst "black blizzard" occurred, later given the name "Black Sunday."

true

Perhaps you are now concerned with the safety of your drinking water. Describe the steps you will take to allay your concern. Information on the safety of your drinking water can be obtained from your local water board or management agency.

true

Saltation occurs close to the ground with grains that are sand size (0.625-2 mm in diameter).

true

Sand grains are the primary cause of abrasion in the desert.

true

Snow that falls in Antarctica does not go away, but builds up over thousands of years.

true

Some sand dunes cannot be classified, due to their irregular shape.

true

The United Nations believes that local communities are most familiar with their own regions and therefore, should be involved in plan development.

true

The chemistry of water in the ground is capable of causing hydrolysis, dissolution, and oxidation of many minerals.

true

The two largest deserts are covered with water.

true

The westerlies are surface winds in the Ferrel cell moving north and deflecting right across the northern hemisphere.

true

Throughout the Coriolis effect, when air warms it contracts and sinks closer to Earth's surface.

true

Pebbles, cobbles, and boulders with flat wind-abraded surfaces are called

ventifacts

Which, according to the text, is not a factor of desert formation?

warm ocean currents against the tropical coastline

Under what conditions would a stream receive base flow during part of the year but provide recharge at other times? In an area that is dry during one season and wet in another season, and where a stream flows from a distant, wet region, the stream would receive base flow during the

wet, dry