Deck 20: The Retreat of Glaciers and the Holocene

Question 1

The ancestors of nearly all Native Americans reached North America slightly before __________ years ago.

A) 30,000
B) 20,000
C) 18,000
D) 13,000

Answer 1

D

Question 2

Soon after the last glacial maximum, about __________ years ago, continental glaciers began to melt away.

A) 12,000
B) 15,000
C) 20,000
D) 22,000

Answer 2

D

Question 3

Moraines reveal that the retreat of glaciers was slow at first, but accelerated after __________ years ago.

A) slightly less than 12,000
B) about 20,000
C) about 15,000
D) about 22,000

Answer 3

C

Question 4

The onset of the Younger Dryas (about 12,800 years ago) was signaled by a(n)

A) destabilization of the ice sheets and deposition of a massive Heinrich layer.
B) unexplained global warming that took place within a decade.
C) rise in the level of oxygen 18 in North Atlantic planktonic foraminifera.
D) mass extinction of the flower Dryas in the northern hemisphere.

Question 5

The end of the Little Ice Age approximately coincided with

A) the winters at Valley Forge of George Washington and his troops.
B) potatoes replacing wheat as the staple on many farms in Europe.
C) Norse Viking settlements being established on Greenland.
D) the great famine-related Irish immigration to North America.

Question 6

The Medieval warm period peaked around __________ AD, and this period included the climate-related collapse of the __________ culture.

A) 920; Anasazi
B) 1180; Mayan
C) 1475; Great Plains
D) 1540; Irish
E) 1950; Four Corners

Question 7

Early Holocene rising sea levels drowned river valleys, thus forming coastal features such as

A) drowned reefs off Florida and many Caribbean islands.
B) the Chesapeake, Delaware, and Mobile bays.
C) the Great Valley of California.
D) fjords like those on the Norwegian coastlines.

Question 8

In the southeastern United States, a(n) __________ forest existed south of the retreating ice sheets about 12,000 years ago.

A) pine
B) deciduous
C) evergreen
D) prairie

Question 9

Bones of many animals that became extinct during early Holocene, which help document the nature of the extinction event in North America, are found

A) in tar pits in California.
B) near Folsom, New Mexico.
C) inside Freisenbhahn cave, Texas.
D) in Siberia and Alaska.

Question 10

Three abrupt sea-level rises between 15,000 and 7000 years ago can be documented by studying

A) Douglas fir trees.
B) moosehorn corals.
C) deciduous forests.
D) prairie potholes.

Question 11

__________ is/are an ancient entity whose component species have evolved in association with one each another.

A) Deciduous forests of the eastern United States
B) Douglas fir forests of the Pacific Northwest
C) Each major plant community on Earth
D) No major plant community on Earth

Question 12

The Clovis people were able to kill woolly mammoth and mastodon using

A) knives with a Clovis point.
B) spears hurled with a spear thrower.
C) spears thrown by hand.
D) a slot in a spear shaft.

Question 13

Beginning in AD 985, the Norse Vikings established an outpost in western Greenland where they raised cattle and herded sheep, which occurred during the

A) Holocene hypsithermal interval.
B) third major cold interval since the retreat of the continental glaciers.
C) Medieval warm interval.
D) Little Ice Age.

Question 14

__________ coincided with the hypsithermal interval.

A) The domestication of plants and animals
B) Global cooling events
C) The North American large mammal extinction
D) Intensification of human hunting

Question 15

Agriculture arrived in southern France about __________ BC.

A) 5400
B) 5700
C) 6000
D) 8500

Question 16

If climate change did not cause the extinction of many large mammals in North and South America during early Holocene, then, according to an alternative hypothesis, _________ did.

A) predators such as the short-faced bear and the dire wolf
B) the Clovis people
C) saber-toothed cats and cheetahs
D) widespread disease

Question 17

If we could go back in time to __________ years ago, we would be at the onset of a post-hypsithermal cold interval that would last for 900 years.

A) 3500
B) 5800
C) 4700
D) 1000

Question 18

The post-glacial subsidence of a peripheral bulge can result in

A) regression of barrier islands and lagoons.
B) land rising faster than sea-level rises.
C) the sea transgressing across the land.
D) the cessation of glacial retreat.

Question 19

Of the carbon dioxide produced by humans, about half ends up in the

A) oceans' biomass.
B) forests' biomass.
C) sea (dissolved in seawater).
D) atmosphere.

Question 20

Wooly mammoths, which the Clovis people hunted, ate __________, and the other large Clovis food item, the mastodons, ate __________.

A) grasses and tundra plants; twigs and conifer needles
B) twigs and conifer needles; grasses and tundra plants
C) beech, hickory, and maple; evergreens and pines
D) evergreens and pines; beech, hickory, and maple

Question 21

In Antarctica, the ice shelves are attached to

A) the ice cap.
B) each other.
C) bedrock.
D) ice streams.

Question 22

Antarctica contains __________ percent of the world's ice.

A) 50
B) 75
C) 85
D) 90

Question 23

An example of a process accelerated by positive feedback driven by global warming is

A) animal migration.
B) the death of coral reefs.
C) desertification.
D) monsoonal rains.

Question 24

An hypothesis about the sudden end of the Younger Dryas interval says that a comet struck Earth or exploded in the atmosphere about 12,800 years ago, triggering a series of events that included all the following EXCEPT

A) the collapse of the Clovis culture.
B) a global warming event that lasted several centuries.
C) possible significant reduction in human populations in many areas.
D) possible extinction of the large mammal populations in many areas.

Question 25

A powerful greenhouse gas that could be released in greater quantities in the future due to global warming is

A) carbon dioxide.
B) methane.
C) water vapor.
D) oxygen.

Question 26

A __________-meter sea-level rise will endanger the homes of about 1 billion people and one-third of the world's crop-growing area.

A) 0.1
B) 1
C) 10
D) 100

Question 27

If the Antarctic ice cap melts, global sea levels will rise more than

A) 6 millimeters.
B) 6 meters.
C) 60 meters.
D) 6 kilometers.

Question 28

Optical measurements of the amount of chlorophyll in the ocean over the span of several years have revealed that marine phytoplankton are becoming less productive because of

A) global warming.
B) monsoonal rains.
C) evaporation rates.
D) desertification.

Question 29

Sea-level rise due to global warming may be most strongly affected by melting of

A) the Antarctic ice cap.
B) the Greenland ice cap.
C) the Arctic tundra.
D) mountain glaciers.

Question 30

The increase in Earth's average surface temperature since 1920 is approximately __________ degrees Celsius, but there has been a sharp increase to nearly _________ degrees Celsius by the year 2000.

A) 0.7; 3.6
B) 0.7; 5
C) 7; 36
D) 7; 50