GEO MIDTERM 2 (Quizzes/Lit. Responses)
Because of the increase in computing power over the last few decades, the size of grid boxes used in atmospheric general circulation models has gotten larger. Select one: True False
False
Benthic foraminifera are ocean bottom-dwelling organisms that form shells of CaCO3. Select one: True False
False
In the Northern Hemisphere, the altitude of the equilibrium line slopes upward into the atmosphere toward the north. Select one: True False
False
After two half-lives, all of a parent radioactive isotope will have decayed to a daughter isotope. Select one: True False
False
For the biological carbon pump to reduce atmospheric CO2: Select one: a. more nutrients must be available in the surface waters. b. the rate of photosynthesis in the surface waters must increase. c. the rate of precipitation over the oceans must increase. d. All of the answers are correct.e. Both A and B are correct.
Both A and B are correct.
The central prediction of the Milankovitch hypothesis is that large oscillations in northern hemisphere ice sheet volume should occur with a periodicity of 100,000 years. Select one: True False
False
800,000-year-old glacial ice has been recovered from the Antarctic ice sheet. Select one: True False
True
Rates of sediment deposition are typically lowest in deep-ocean settings. Select one: True False
True
What type of rock can be dated using potassium-40/argon-40 radiometric dating? Select one: a. any rock that contains carbon b. basalts c. corals d. sedimentary rocks e. All of the answers are correct.
b. basalts
What does the presence of expanded active sand dunes in Arabia, North Africa, and Australia suggest about last glacial maximum conditions there? Select one: a. Climate must have been drier to allow the sand to mobilize. b. Ice sheets must have been present in these regions to produce the observed sand. c. Summer monsoons must have been stronger to blow the sand toward the north. d. Wetter conditions must have prevailed to create more stream erosion and sand production. e. Winds must have been weaker to allow the sand to persist.
a. Climate must have been drier to allow the sand to mobilize.
If small, isolated ice sheets existed in North America and Eurasia for millions of years prior to 2.75 million years ago, why did ice sheets expand at this time? Select one: a. Gradual global cooling caused a glaciation threshold to be crossed. b. There was a sudden decrease in insolation due to a meteorite impact. c. The lag time between summer insolation minima and ice growth is millions of years. d. North America and Eurasia were tectonically uplifted above the equilibrium line. e. Orbitally controlled changes in insolation were initiated then.
a. Gradual global cooling caused a glaciation threshold to be crossed.
A powerful volcanic eruption whose airborne particles lead to a reduction in solar energy for a period of six months would have what effect on the deep ocean? Select one: a. The deep ocean would change very little, as the response time of the deep ocean is too slow for it to show significant changes. b. The deep ocean would cool quickly, tracking the reduction of solar energy. c. There would be a highly dynamic response in the deep ocean to the reduction of solar energy. d. The deep ocean would respond with varying amplitude to the changes in solar energy.
a. The deep ocean would change very little, as the response time of the deep ocean is too slow for it to show significant changes.
Why is there a phase lag between changes in insolation and changes in ice volume? Select one: a. The response time of the ice sheet is very slow. b. No ablation can occur until the response time of an ice sheet has elapsed. c. Changes from high to low insolation are instantaneous, but changes in ice volume are not. d. Both A and C are correct. e. All of the answers are correct.
a. The response time of the ice sheet is very slow.
Which of the following is an example of a biotic proxy that could be used for reconstructing past climate change? Select one: a. a data set of temperature-sensitive planktic foraminifera species changes over time at a deep marine site b. instrumental temperature measurements recorded at a weather station c. burial flux of ice-rafted debris at a deep marine site d. isotopes of oxygen in benthic foraminifera from a deep marine site e. All of these are examples for reconstructing past climate change.
a. a data set of temperature-sensitive planktic foraminifera species changes over time at a deep marine site
At the last glacial maximum, summer: Select one: a. and winter insolation levels were similar to those of today. b. and winter insolation levels were both greater than today. c. insolation was greater, and winter insolation was less than today. d. insolation was much less, and winter insolation was much greater than today. e. and winter insolation levels were the opposite to those of today.
a. and winter insolation levels were similar to those of today.
Ocean sediment: Select one: a. can be used to reconstruct climate on land. b. distribution patterns remain constant over geologic time at any particular location on the seafloor. c. is a lower-quality climate archive than most records from land due to the high rate of erosion along the seafloor. d. All of the answers are correct. e. None of the answers is correct.
a. can be used to reconstruct climate on land.
Which of the following is an example of an internal response to climate variations? Select one: a. changes in forest cover b. changes in plate tectonics c. changes in Earth's orbit d. changes in Sun's strength e. All of these are examples.
a. changes in forest cover
Understanding change through time in the flow of carbon between the atmosphere, biosphere, and ocean is best accomplished with a: Select one: a. chemical reservoir model. b. mass balance model. c. one-way transfer model. d. reservoir-exchange model. e. None of the answers is correct.
a. chemical reservoir model.
snow that has survived one summer is denser than fresh snow, and is called: Select one: a. firn b. thalweg c. bergschrund d. clathrate e. ogive
a. firn
The lab in which the first analyses were made of the Greenland ice cores was located Select one: a. in a hole dug in the surface of the glacier b. in the National Ice Core Laboratory in Denver Colorado c. at the CRREL laboratory in Hanover NH d. at Princeton University e. none of the above
a. in a hole dug in the surface of the glacier
How does ice retain a record of past atmospheric gas composition? Select one: a. in trapped air bubbles b. within the frozen water molecules c. in air trapped at the bedrock-ice interface d. indirectly through the composition of included volcanic ash layers e. All of the answers are correct.
a. in trapped air bubbles
For what portion of geologic time do climate scientists have access to the climate archive consisting of sediments preserved in ocean basins? Select one: a. younger than 150 million years b. only younger than 15 million years c. only younger than 1.5 million years d. only younger than 150,000 years e. None of the answers is correct.
a. younger than 150 million years
the modern warm period we are in today started Select one: a. 100,000 years b. 10,000-15,000 years c. 150,000 years d. 50,000 years e. 100 years
b. 10,000-15,000 years
the dust found in the Greenland ice core came from Select one: a. Iceland b. Asia c. Scandanavia d. North America e. Hawaii
b. Asia
Numerical simulations of past climate occur in an ordered three-step sequence. The order is: Select one: a. Run a climate simulation → Specify boundary conditions → Analyze the climate data output by comparing them with independent geologic data. b. Specify boundary conditions → Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data. c. Analyze the climate data output by comparing them with independent geologic data → Specify boundary conditions → Run a climate simulation. d. Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data → Specify boundary conditions. e. None of the answers is correct.
b. Specify boundary conditions → Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data.
Which of the following is true about the large glaciation phase in the Northern Hemisphere? Select one: a. Ice sheets disappeared at each summer insolation maximum. b. The largest oscillations in ice volume occur at around 100,000 years. c. The phase ended around 0.9 million years ago. d. The sequence of ice growth and melting follows Milankovitch's theory precisely. e. All of the answers are correct.
b. The largest oscillations in ice volume occur at around 100,000 years.
Why is a "spin-up" interval necessary when altering boundary conditions in an A-GCM? Select one: a. The model requires large amounts of stored power to achieve the simulation. b. The model requires simulated time to reach a state of equilibrium. c. The model simulations start slowly and pick up speed through time. d. Both A and C are correct. e. All of the answers are correct.
b. The model requires simulated time to reach a state of equilibrium.
Which of the following has the greatest influence on ice sheets size? Select one: a. accumulation in the winter b. ablation in the summer c. the density of ice crystals d. insolation in the winter e. Both A and D are correct.
b. ablation in the summer
What do we call the features that are altered to test hypotheses of climate change within a physical climate model? Select one: a. aerosols b. boundary conditions c. geochemical tracers d. grid boxes e. None of the answers is correct
b. boundary conditions
What do we call the features that are altered to test hypotheses of climate change within a physical climate model? Select one: a. aerosols b. boundary conditions c. geochemical tracers d. grid boxes e. None of the answers is correct.
b. boundary conditions
What is the most important contributor to the δ18O signal in marine foraminifera over the last one million years? Select one: a. changing temperature of ocean water b. changing volume of ice sheets c. rate of volcanic activity in oceanic spreading centers d. source of continental bedrock for chemical weathering e. None of the answers is correct.
b. changing volume of ice sheets
What type of atmospheric model treats Earth's climate system in a globally averaged fashion? Select one: a. atmospheric general circulation models b. column models c. O-GCMs d. two-dimensional models e. None of the answers is correct.
b. column models
the best way to measure the detailed variations in acidity of ice is by Select one: a. a pH test b. continuous measurements of electrical conductivity c. layer counting d. counting air bubbles in the ice e. none of the above
b. continuous measurements of electrical conductivity
What is the main source of iron for marine life in the oceans today? Select one: a. dust from meteorites b. erosion of the land c. undersea volcanoes d. oxidation of foraminifera e. None of the answers is correct.
b. erosion of the land
Prior to the development of marine δ18O records of ice volume, how many periods of glaciation did most geologists believe had occurred? Select one: a. one b. four or five c. eight d. twelve e. fifty
b. four or five
Drilling ice cores: Select one: a. is done in the winter season. b. has provided an archive of climate signals of the last several thousand years. c. occurs at the margins of ice sheets so that drilling can penetrate the underlying bedrock. d. All of the answers are correct. e. Both A and B are correct.
b. has provided an archive of climate signals of the last several thousand years.
In which of the following scenarios would the resolution of the climate record (degree of resolvable detail) be greatest? Select one: a. high sediment influx rate, deep mixing b. high sediment influx rate, shallow mixing c. low sediment influx rate, deep mixing d. low sediment influx rate, shallow mixing e. Resolution would be the same for all of the above cases.
b. high sediment influx rate, shallow mixing
What is the major uncertainty about the size of the ice sheets at the last glacial maximum that remains unresolved today? Select one: a. the location of the southern limit of northern hemisphere ice sheets b. how thick the northern hemisphere ice sheets were c. exactly which ice sheets had marine bases d. whether Antarctica had a large ice sheet or was barren of ice e. All of the answers are correct.
b. how thick the northern hemisphere ice sheets were
What ice dating technique is commonly used for ice cores without annual layering? Select one: a. layer-count method b. ice flow modeling c. summer d. paleomagnetism e. radiocarbon f. All of the answers are correct.
b. ice flow modeling
The scope of time focused on in the textbook: Select one: a. amounts to most of the span of Earth history. b. includes the last several hundred million years. c. begins after the extinction of the dinosaurs. d. does not include the period in which humans evolved. e. All of the answers are correct.
b. includes the last several hundred million years.
Chemical weathering of continental rocks: Select one: a. is accelerated in cold, dry climates. b. involves chemical interactions between the soil/rock and atmospheric CO2 and H2O. c. produces ions that are most commonly transported to the deep sea via eolian processes. d. supplies ions to the deep sea, which pollute the waters making it difficult for ocean plankton to thrive. e. None of the answers is correct.
b. involves chemical interactions between the soil/rock and atmospheric CO2 and H2O.
What was the main cause of tropical cooling during the last glacial maximum? Select one: a. direct thermal impact from ice sheets b. lower greenhouse gas concentrations c. reduced solar insolation d. All of the answers are correct. e. None of the answers is correct.
b. lower greenhouse gas concentrations
Which two major types of biotic data are most important to climate reconstructions? Select one: a. petrified trees and corals b. microfossils of plankton and pollen c. dinosaurs fossils and corals d. leaves and grass impressions in sedimentary rocks e. insect and fish remains
b. microfossils of plankton and pollen
In which of the following depositional settings is the disturbance of sediments least likely over the long term? Select one: a. the coastal margin in a storm-prone region b. the deep ocean floor c. a lake in a tectonic basin d. in the ocean along a steep continental slope e. the ocean floor in 100 meters of water depth
b. the deep ocean floor
the longest tree ring records from living trees combined with older wood cover how many years Select one: a. 5000 b. 10000 c. 12000 d. 150000 e. 200
c. 12000
When was the last glacial maximum? Select one: a. 240,000 years ago b. 120,000 years ago c. 21,000 years ago d. 10,000 years ago e. 5,000 years ago
c. 21,000 years ago
How does vertical ice sheet growth serve as a climate feedback? Select one: a. As ice sheets grow vertically, they shrink laterally. b. As ice sheets grow vertically, the rate of ice melting at the margins increases. c. As ice sheets grow vertically, they contribute to their own positive mass balance by growing upward into a regime of accumulation. d. As ice sheets grow vertically, the equilibrium line must move toward the northern edge of an Arctic-rim continent. e. Both C and D are correct.
c. As ice sheets grow vertically, they contribute to their own positive mass balance by growing upward into a regime of accumulation.
Which of the following is true about the Milankovitch theory of the astronomical control of ice sheet size? Select one: a. 40°N is thought to be the latitude most sensitive for low insolation values. b. It predicts that ice melts when winter's insolation is high. c. It recognizes that top-of-the-atmosphere summer insolation varies by as much as 12% at 65°N latitude. d. Both A and C are correct. e. All of the answers are correct.
c. It recognizes that top-of-the-atmosphere summer insolation varies by as much as 12% at 65°N latitude.
What is a key difference between the sediment that makes up moraines and the sediment that makes up loess? Select one: a. Moraines are deposited by wind, while loess is deposited by water. b. Moraines are found only on continents, while loess is found only in oceans. c. Moraines are made of sediments ranging from large rocks to clay, while loess is made of strictly fine sediments. d. Moraine sediments are an indicator of dry conditions, while loess is an indicator of wet conditions. e. None of the answers is correct.
c. Moraines are made of sediments ranging from large rocks to clay, while loess is made of strictly fine sediments.
Why are fossil remains from continents more useful than fossils in ocean sediments for climate reconstruction prior to 170 million years ago? Select one: a. Organisms found in ocean sediments have not changed significantly. b. Ocean sediments do not preserve fossils. c. Seafloor older than 170 million years does not exist. d. Both A and B are correct. e. All of the answers are correct.
c. Seafloor older than 170 million years does not exist.
Which of the following is true about historical climate archives? Select one: a. They are not useful for climate reconstruction beyond the last few centuries. b. They are useful in climate reconstruction only when they include thermometric observations. c. They can include observations of climate-related phenomena such as found in agricultural records. d. They exist only for Europe and North America. e. None of the answers is correct.
c. They can include observations of climate-related phenomena such as found in agricultural records.
Which of the following is true about land vegetation 20,000 years ago compared to today? Select one: a. Most regions on Earth were wetter and more vegetated. b. Rain forests in the tropics were more extensive. c. Total land vegetation was reduced by about 25%. d. Vegetation on land contained more organic carbon. e. None of the answers is correct.
c. Total land vegetation was reduced by about 25%.
Diatoms: Select one: a. are a type of marine pollen. b. are calcareous (i.e., made of calcite, CaCO3). c. depend heavily on nutrient supply from either land or upwelling waters for their abundance in the surface waters. d. All of the answers are correct. e. Both B and C are correct.
c. depend heavily on nutrient supply from either land or upwelling waters for their abundance in the surface waters.
A sensitivity test performed in an atmospheric climate model (A-GCM): Select one: a. requires changing all known boundary conditions at the same time. b. simulates the full state of the climate system at some time in the past. c. describes the case when only one boundary condition is altered in relation to the present-day configuration to study the unique impact of that boundary condition on the modeled system. d. Both A and B are correct. e. Both B and C are correct.
c. describes the case when only one boundary condition is altered in relation to the present-day configuration to study the unique impact of that boundary condition on the modeled system.
Sediment archives: Select one: a. typically accumulate on high exposed spots (e.g., mountain tops) on Earth's surface. b. will have recorded the same climatic event at the same depth everywhere. c. have a temporal resolution dependent on the rate that the sediment accumulated and whether it has been disturbed (mixed-up) after deposition. d. All of the answers are correct. e. Both A and C are correct.
c. have a temporal resolution dependent on the rate that the sediment accumulated and whether it has been disturbed (mixed-up) after deposition.
Which of the following conceptual phases of the long-term evolution of ice sheets are we in at the present day? Select one: a. preglaciation phase b. small glaciation phase c. large glaciation phase d. postglaciation phase e. None of the answers is correct.
c. large glaciation phase
A climate scientist uses data from a sediment core to quantify changes in the rate of accumulation of organic material, sand, and diatoms in a lake. She is developing a: Select one: a. chemical reservoir model. b. mass balance model. c. one-way transfer model. d. reservoir-exchange model. e. None of the answers is correct.
c. one-way transfer model.
Modern sediment accumulating in the North Pacific Ocean is largely derived from: Select one: a. settling of siliceous plankton. b. ice-rafting of sand and gravel from land. c. settling of windblown silt and clay. d. All of the answers are correct. e. None of the answers is correct.
c. settling of windblown silt and clay.
The aircraft that carried all of the equipment to and from the top of the Greenland Ice Sheet were/are based out of the: Select one: a. the 10th Mountain Division in Ft. Drum NY b. Copenhagen c. the 109th (Stratton) Air National Guard Base in Scotia (Glenville) NY d. the National Core Laboratory in Denver Colorado e. none of the above
c. the 109th (Stratton) Air National Guard Base in Scotia (Glenville) NY
Which of the following is an example of a tectonic process? Select one: a. the increasing strength of the Sun over the last 4.55 billion years b. The changing amount of solar radiation by season c. the opening and closing of ocean basins d. Both A and B are correct. e. All of the answers are correct.
c. the opening and closing of ocean basins
The science of reconstructing past climates advances best when: Select one: a. mismatched data from geologic archives and model outputs are disregarded or thrown out. b. climate models strive toward using the largest grid box possible. c. the strengths and limitations of both the data derived from geologic archives and the models are constantly tested against one another. d. All of the answers are correct. e. Both B and C are correct.
c. the strengths and limitations of both the data derived from geologic archives and the models are constantly tested against one another.
The percentage of the Earth's surface that is presently covered by permanent ice is: Select one: a. 5% b. 25% c. 30% d. 10% e. 1%
d. 10%
What percent of Earth's continental area was covered by ice at the last glacial maximum according to the CLIMAP reconstruction? Select one: a. 1% b. 7% c. 16% d. 25% e. 49%
d. 25%
How does the study of fossils complement radiometric dating in establishing the age of rocks? Select one: a. Fossils tend to be more widely distributed in rock sequences than igneous rocks. b. The unique and unrepeated sequence of living things throughout Earth history allows the correlation of fossil-bearing rocks from a wide geographic area. c. Short-lived, geographically widespread organisms in a radiometrically dated fossil sequence can serve as time markers wherever they are found. d. All of the answers are correct. e. None of the answers is correct.
d. All of the answers are correct
Ancient coral reefs: Select one: a. can be dated by radiometric decay methods. b. are a proxy for sea level change over the last 150,000 years. c. confirm the δ18O record interpretation that the last interglacial was 125,000 years ago. d. All of the answers are correct. e. Both B and C are correct.
d. All of the answers are correct.
The ocean is an important and useful reservoir in geochemical mass balance models because: Select one: a. it receives almost all the erosional products from the continents. b. it interacts with ice, vegetation, and sediment geochemical reservoirs. c. it deposits geochemical tracers in well-reserved sedimentary records. d. All of the answers are correct. e. Both A and B are correct.
d. All of the answers are correct.
What is the freezing point of water? Select one: a. 32°F b. 273K c. 0°C d. All of the answers are correct.
d. All of the answers are correct.
Consider the study of past climate change, and determine which of the following is (are) correct. Select one: a. The resolution of climate archives is generally greater in the recent past than for the distant geologic past. b. The types of climate archives available are generally more diverse in the recent past than they are for the distant geologic past. c. Climate proxies allow scientists to directly read the temperature of the past. d. Both A and B are correct. e. None of the answers is correct.
d. Both A and B are correct.
How does ice move? Select one: a. It slips along its base. b. It flows internally from regions of net accumulation to regions of net ablation. c. It flows internally in the low-elevation, warm areas of the ice sheet, but not in the high- elevation, cold areas of the ice sheet. d. Both A and B are correct. e. Both B and C are correct.
d. Both A and B are correct.
What explains the dramatic cooling of North Atlantic surface temperatures during the last glacial maximum? Select one: a. A flow of cold winds blew off of the North American ice sheet. b. The Greenland ice sheet extended south to 50°N latitude. c. The Gulf Stream and North Atlantic Drift remained farther south than today. d. Both A and C are correct. e. All of the answers are correct.
d. Both A and C are correct.
What factor accounts for the present elevation of ancient coral reefs? Select one: a. the amount of uplift following reef formation b. the current temperature of ocean water c. the position of global sea level at the time of reef formation d. Both A and C are correct. e. Both A and B are correct.
d. Both A and C are correct.
Which of the following is true about our understanding of the history of Earth? Select one: a. Earth formed 4.55 billion years ago. b. Our knowledge of conditions on Earth is clear for the entire span of Earth history. c. Early deposits that could give insight into Earth history have been eroded away. d. Both A and C are correct. e. All of the answers are true about our understanding.
d. Both A and C are correct.
Which of the following last glacial maximum ice sheets was the largest by volume? Select one: a. Barents ice sheet b. Cordilleran ice sheet c. East Antarctic ice sheet d. Laurentide ice sheet e. Scandinavian ice sheet
d. Laurentide ice sheet
At the last glacial maximum, where was spruce pollen most abundant in North America (according to lake sediments)? Select one: a. California and Nevada b. Florida and Mexico c. Northeastern Canada d. Northern United States e. All of the answers are correct.
d. Northern United States
What were the climatic conditions in the western United States during the last glacial maximum? Select one: a. The northwest was wetter while the southwest was drier than today. b. The region was drier than today. c. The region was wetter than today. d. The southwest was wetter while the northwest was drier than today. e. None of the answers is correct.
d. The southwest was wetter while the northwest was drier than today.
What traits of plankton and pollen make them especially useful as climate proxies? Select one: a. The species they represent have poorly-defined climate preferences. b. They are found in radiometrically-dated granites. c. They are produced only when climate is warm. d. They are widely distributed and abundant. e. All of the above are traits.
d. They are widely distributed and abundant.
the scientist who determined the relationship between air temperature and the oxygen isotopic composition of precipitation is Select one: a. Paul Mayewski b. Deb Meese c. Henri Bader d. Willi Dansgaard e. Tony Gow
d. Willi Dansgaard
The Younger Dryas was Select one: a. a warm period, like today, that ended about 11,500 years ago b. a cold period like the last ice age that ended about 11,500 years ago c. ended with a rapid warming of about 10°F in a decade d. both B and C e. none of the above
d. both B and C
Mismatches between climate data output from circulation models and geologic data: Select one: a. always involve the misinterpretation of geologic data. b. are virtually impossible to resolve. c. cannot result from inadequacies in the modeled climate system. d. often result in the refinement of boundary conditions used in the models. e. All of the answers are correct.
d. often result in the refinement of boundary conditions used in the models
Which of the following is not an example of a type of plankton? Select one: a. coccoliths b. diatoms c. planktic foraminifera d. pollen e. radiolaria
d. pollen
the evaporation of ice without first melting it, is called Select one: a. transpiration b. evapotranspiration c. short wave evaporation d. sublimation e. BOTH C and D
d. sublimation
During the last glacial maximum, where was the highest rate of deposition of ice-rafted debris in the North Atlantic Ocean? Select one: a. near the Arctic Circle b. near their sources areas in Greenland and Canada c. near their source areas in Scandinavia and Iceland d. where the icebergs first encountered warm water, at ~50ºS e. where the icebergs first encountered warm water, at ~65ºS
d. where the icebergs first encountered warm water, at ~50ºS
If all of the glacial ice on Earth were to melt, sea level would rise by Select one: a. 10 feet b. 100 feet c. 1000 feet d. 10,000 feet e. 200 feet
e. 200 feet
Dating, and therefore correlation, of different sediment sequences may be accomplished using: Select one: a. radiometric dating of unstable isotopes. b. the fossil record (i.e., biostratigraphy). c. identification of a marker bed, such as a distinct ash layer. d. orbital tuning. e. All of the answers are correct.
e. All of the answers are correct.
Where is most natural methane produced? Select one: a. in the tropics b. in the circumarctic c. in wetlands d. in anoxic environments e. All of the answers are correct.
e. All of the answers are correct.
Which of the following is a source of geochemical climate data? Select one: a. benthic foraminifera b. cave deposits c. glacial ice d. trees e. All of these are sources.
e. All of these are sources.
For the biological carbon pump to reduce atmospheric CO2: Select one: a. more nutrients must be available in the surface waters. b. the rate of photosynthesis in the surface waters must increase. c. the rate of precipitation over the oceans must increase. d. All of the answers are correct. e. Both A and B are correct.
e. Both A and B are correct.
Past climate change: Select one: a. informs scientists about climate drivers and system interactions, which are necessary for predicting future climate change. b. occurred only in the last 300 million years. c. has been influenced by both natural and anthropogenic drivers. d. All of the answers are correct. e. Both A and C are correct.
e. Both A and C are correct.
Radioactive decay of unstable isotopes can be used to determine the age of some rocks, corals, or organic matter because the: Select one: a. amount of parent or daughter isotope can be measured. b. rate of decay of the daughter isotope to the parent isotope occurs at a known rate for each particular isotope. c. rate of decay is essentially a clock marking the time that has passed since that material formed. d. All of the answers are correct. e. Both A and C are correct.
e. Both A and C are correct.
Where do continental ice sheets exist today? Select one: a. in the central Arctic b. on Antarctica c. on Greenland d. Both A and B are correct. e. Both B and C are correct.
e. Both B and C are correct.
Why are CH4 variations over the last 350,000 years as measured in ice cores linked to changes in July insolation? Select one: a. changes in the Antarctic-region biological pump b. changes in the strength of the summer monsoon in tropical and subtropical regions c. changes in the heating of the high northern-latitude wetlands d. All of the answers are correct. e. Both B and C are correct.
e. Both B and C are correct.
What type of ocean sediment is most common in areas of high oceanic productivity? Select one: a. CaCO3-rich b. deep-sea clay c. ice-rafted d. land-margin e. SiO2-rich
e. SiO2-rich
Which of the following is not an example of a climate archive that can be dated by counting annual layers? Select one: a. varved sediments b. trees in regions of seasonal climate variations c. ice sheets d. corals e. deeply-mixed ocean sediments
e. deeply-mixed ocean sediments