Geology Exam 3 (FINAL)

Notice the annual oscillations of carbon dioxide. What causes this repetitive change?

photosynthesis in deciduous trees

What consequence does the diagram illustrate, and why did this happen?

subsidence due to overpumping

What do geologists mean when they say that a rock has a porosity of 30%?

A rock with 30% porosity consists of 30% pore space.

What makes hard water "hard"?

calcium and magnesium

hundreds to perhaps a thousand years

dendrochronology (tree ring studies)

car and truck exhaust

photochemical smog

Groundwater is a part of the water cycle, just like rivers, lakes, and the oceans are. How does the rate of groundwater flow compare to that of rivers and ocean currents?

Groundwater moves much slower than either rivers or ocean currents.

While many resources on Earth are finite (nonrenewable), there are some critical resources that are potentially renewable. Which of the following resources could be renewable if they are managed properly?

Renewable if Managed Properly: - freshwater - soil - wood products

Pumping of groundwater at high rates can cause hazards beyond simply running a well dry. Which of the following hazards are associated with groundwater extraction?

groundwater hazards: - subsidence - saltwater infiltration - contamination due to change in groundwater flow direction other hazards: - liquifaction - creep

A variety of natural processes can affect Earth's atmospheric temperature in a relatively short period of time. Which of the following would contribute to an overall cooling of Earth's atmospheric temperature?

increasing the abundance of volcanic aerosols increasing the albedo of the Earth's surface

The type of bedrock groundwater flows through can have a significant effect on associated hazards. What kind of bedrock is most susceptible to forming sinkholes?

limestone

Which of the following ore resources have expected lifetimes of "0 years" in the United States?

manganese chromium

Diagram A shows two depictions of the fundamental building block of silicate minerals, the most abundant minerals. What is it called?

silicon-oxygen tetrahedron

What is the name of the karst feature in the photo?

sinkholes

Which of the following best describes permeability?

the ability of fluid to pass through material via interconnected pores

The image below shows a model prediction of future global temperature increases. Based on the image, which is predicted to warm more, the oceans or the continents?

the continents

In the diagram above, what do the arrows represent?

the flow paths of the groundwater

What type of karst terrain does the photo show?

tower karst

Which characteristics are essential to defining a geologic occurrence as an ore deposit?

- It has a high concentration of a metal - It contains enough ore to make mining economical.

Identify statements true of metals.

- Metals can conduct electricity - Metals are malleable - Copper is an example of a metal.

If you were creating a model to estimate future CO2 concentrations, which of the following would you consider?

A Consideration natural: - influences on atmospheric carbon - relative amount of fossil fuel consumption - positive feedback cycles

Which of the following environmental conditions are the result of deforestation?

A Result of Deforestation: - increased atmospheric carbon - increased soil erosion - loss of habitat - loss of biodiversity

From the video, you can see that melting ice, plate tectonics, volcanism, and thermal expansion all drive sea-level change. Some of these causes are present regardless of temperature fluctuations. Others are directly affected by increases or decreases in temperature. From the choices below, select the temperature-dependent drivers of sea-level rise.

A Temperature-Dependent Driver: - melting ice - thermal expansion of water

Identify the water table on the diagram.

A is the water table

When contamination does occur, what options do environmental consulting businesses have to monitor and clean up plumes of pollution?

- Use the process of bioremediation. - Drill test wells to determine the direction and extent of contamination. - Use steam injection wells to drive pollutants to extraction wells.

In the carbon cycle, carbon transfers between different reservoirs. Which of the following results in the release of carbon dioxide into the atmosphere?

- burning fossil fuels - animal respiration - metamorphism of limestone - volcanism

What factors determine porosity?

- dissolution of rock - the amount of compaction - sediment sorting

What characteristics define a mineral?

- solid - crystalline material with a definable chemical composition - naturally occurring - often inorganic

What factors control permeability?

- the shape of the paths (conduits) through the material; straighter paths have faster flow rates - size of the paths (conduits) through the material - the number of paths (conduits) through the material

Order the stages in the development of the features in the photo.

1. Development of caves and passages 2. Roofs of rooms collapse 3. Erosion of roof material from passage 4. Walls remain intact, creating spires

Determine which properties are characteristic of an aquifer or an aquitard.

Aquifer - high porosity and permeability - coarse gravel - poorly cemented sandstone Aquitard - shale - low permeability - well-cemented sandstone

Which of the materials shown in diagrams A and B has greater porosity, and which has greater permeability?

B has the greatest porosity and permeability.

The Earth is constantly experiencing change. Some of the changes are cyclic, meaning that there is evidence of the change occurring multiple times in the Earth's history. Other changes are unidirectional, meaning that the change does not repeat. Sort the changes shown below based on whether they are cyclic or unidirectional.

Cyclic Changes: - creation of supercontinents - sea-level change - carbon movement Unidirectional Changes: - evolution of the atmosphere - biological complexity

From the list of gases below, select the gases that are considered greenhouse gases

Greenhouse Gas: - H20 - C02 -CH4 NOT: - N2 - 02

How does the unsaturated zone differ from the saturated zone?

In the saturated zone, all pore spaces are completely filled. In the unsaturated zone, pore spaces are filled with water and air.

Through which area does infiltration from the surface take place?

Infiltration takes place through the unsaturated zone.

Is this an indication of where groundwater is available or an indication of the type of bedrock present?

Karst distribution indicates where the bedrock is limestone.

The interaction between groundwater and limestone produces unique land features, like caves, sinkholes, and sharp hilltops or ridgelines. These landscapes are referred to as karst topography.

Limestone is precipitated on the floor of the ocean

Referring to the figure below, does groundwater in the unconfined aquifer mix easily with that in the confined aquifer?

No, because aquitard impedes the flow between the two aquifers.

What is porosity?

Porosity refers to the percent of pore space in a rock.

Select probable causes and unlikely causes for a decrease in the level of the water table.

Probable Causes: - urbanization - drought - well usage Unlikely Causes: - recharge

This photograph shows a small stream coming out of a collapsed coal mine. The black layer is coal. The underlying strata consist of gray sandstone and shale. The orange coloring on the surface of the outcrop consists of iron oxide minerals and bacteria. The iron comes from the oxidation of __________ in the coal. The water coming from the mine is __________.

Pyrite; acidic

Why did a cone of depression develop at the base of the well at point Y?

The cone of depression formed because water was pumped too quickly, causing drawdown.

Why are there no surface streams in the photo?

Water that falls on the surface drains into the subsurface through sinkholes.

Which of these can cause hot-spring formation?

circulation of groundwater in areas where volcanoes are active or were recently active rising of groundwater to the surface from great depths

Based on your knowledge of karst topography, what is the most likely bedrock in the area of the photo?

limestone

The maps above show the numbers of days with temperatures above 32ºC for 1961-1971 (left) and the projected numbers of days for 2080-2099 (right). Using the maps as a guide, select the possible consequences of the predicted change in the numbers of days with temperatures above 32ºC.

more heat waves longer summers more droughts decreased snowpack

The images above show the change in the number of days of the year during which melting occurred in Greenland in 1979-2007 (left) and 2012 (right). What are consequences of this change?

more melting of glacial ice higher sea level

hundreds of thousands of year

oxygen isotopes in ice cores

tens of thousands of years

pollen counts in soil

Which of the materials shown in photos A (quartz) and B (glass) is a mineral?

quartz

Select the statement(s) true of the relationship between glaciation and sea level.

The amount of glacial ice stored on land affects global sea level. During warmer climates, glaciers melt and sea level rises.

Which of the following labeled points represents the perched water table in the diagram below?

The perched water table is labeled B.

How does the rate of groundwater flow compare with that of ocean currents or river currents?

The rate of groundwater flow is slower than that of surface-water currents.

How does the recharge area differ from the discharge area?

The recharge area is where water enters the ground and percolates downward. The discharge area is where water flows back to the surface.

What is a contaminant plume, and in which direction does it move, relative to groundwater flow?

a cloud of contaminated water that moves in the same direction as groundwater

Which of the following describes a rock that has high porosity but low permeability?

a rock that has a lot of pore space, but those spaces are not connected

emission of chlorofluorocarbons (CFCs)

ozone depletion

nuclear power generation

radioactive waste

Rank the following areas in order of largest to smallest change in average temperature since 1880.

1. Northern Canada 2. Western Europe 3. Australia 4. Southern Africa 5. Eastern Pacific Ocean 6. Antarctic Ocean

Order the steps in the formation of a placer ore.

1. Ore-bearing rock becomes exposed at the ground surface 2. Erosion of ore-bearing rock takes place 3. Metal grains become concentrated in stream gravel 4. A placer deposit is formed

Based on the modeling of water-level change, rank the states within the High Plains aquifer system by the largest amount of groundwater decline over the greatest land area.

1. Texas 2. Kansas 3. Colorado 4. New Mexico 5. Nebraska

Use this graph to rank the sources of anthropogenic CO2 in 2010 based on their relative contribution.

1. coal 2. petroleum 3. natural gas 4. cement production

The anthropogenic changes that the Earth experiences are directly tied to pressures applied by the growing human population. Take a look at the graph below. Based on the graph, what was the approximate human population in 2018?

7.6 billion people

What characteristic must groundwater have in order to dissolve limestone?

Groundwater must be acidic to dissolve the limestone.

Referring to the figure, why did the well at Point X dry up?

Overpumping of the well at point Y caused drawdown.

Sort the properties of a passage and a room in a cave network.

Passage - may be a conduit for underground streams - tunnel-shaped corridors - often follow preexisting joints Room - develop in the most soluble limestone - may have an underground lake - has large, open spaces

At a given location, which is higher: a perched water table or the regional water table?

Perched water tables sit higher than the regional water tables.

Which of these are characteristics of either porosity or permeability?

Permeability is a measure of how well the pores are connected. Porosity is a measure of the amount of the substance composed of empty spaces.

Sort the causes of climate change based on whether they act over short-term (tens to hundreds of thousands of years) or long-term (hundreds of millions of years) time scales.

Short-term Causes: - high albedo from vast glaciers - eccentricity of Earth's orbit - tilt of Earth's axis Long-term Causes: - plate tectonics - removal of CO2 via chemical weathering processes - large-scale ocean circulation

This diagram shows the water table and cones of depression developed around two groundwater wells. Which of the following statements accurately describe what is happening in the subsurface?

The size of the cone of depression is primarily a function of pumping rate. Well A will run dry before Well B.

What defines the water table in an area?

The water table is the horizon between the unsaturated zone and the saturated zone.

What is the relationship between a pond's surface and the water table shown here?

The water table is the same as the pond surface.

sulfur-containing aerosols

acid rain

Changes can be considered as being naturally occurring or anthropogenic—that is, resulting from human activity. Which of the following changes are anthropogenic?

anthropogenic: - deforestation - mining - increase in carbon atmospheric carbon dioxide since 1800 naturally occurring: - supercontinent formation and breakup - planetary differentiation

Which area represents the most easily accessible major aquifers?

b

If the rate of groundwater pumping removes water from the aquifer faster than it can be recharged by natural flow, the water table can be drawn down locally. What is this feature called?

cone of depression

Which of these are characteristics of an artesian well?

does not require pumping penetrates a confined aquifer

Identify the materials that are made from nonmetallic resources.

drywall granite countertops concrete

What process yields the mineral crystals found on the floor of a salty desert lake as it dries out, as shown in diagram C?

evaporation of supersaturated water and the precipitation of salt

This image shows an eruption of the Old Faithful Geyser in Yellowstone National Park. Which of the following provides the source of heat for the water that erupts from this geyser?

heat from molten rock in the subsurface

This image shows a close-up view of a piece of pumice that was washed up onto a beach in Italy. Which of the following sets of properties allow this volcanic rock to float on water?

high porosity, low permeability

Let's look at one of the cyclic changes in greater detail. Just because sea level is rising today, it does not mean that today is the highest sea level has ever been. For perspective, look at the graph below. It shows past sea levels compared to today (red line). In the last 200 million years, was sea level generally higher or lower than it is today?

higher than today

a few million years

microfossils in soil cores

Which of the following household materials do not originate from mineral resources?

natural rubber used in footwear

Define the technologies that can clean up groundwater contamination.

perm. reactive: materials that react with contaminants chemically transform them into safer, less soluble components bioremediation: injection of oxygen and nutrients to promote bacterial growth extraction wells: pumping contaminants out of the ground

It is pretty clear that the Earth is warming and will likely do so for the foreseeable future. But why should we care? What does a warming actually mean for humanity?

rise in sea level stronger storms increased wildfires shift in climate belts reduction in glaciers

Removal of groundwater faster than recharge/replenishment results in groundwater depletion. Which of the following is a consequence of overpumping?

saline intrusion subsidence pore collapse

Which of the following is a mineral?

salt

Which of the following is not an environmental hazard of large-scale mining?

sediment liquefaction that can compromise mining tunnels and neighboring processing plants

This image shows Grand Prismatic Spring in Yellowstone National Park. The bright colors around the edge of the pool are a result of which of the following?

thermophilic bacteria and archaea

How does water travel from the land surface into the subsurface to become groundwater?

through infiltration