Final Exam: Ancient Climate and the Ice Age World Flashcards
How did the global climate change over the course of the Cenozoic era?
Paleogene: very high temperatures
Neogene: temperature is going down (cooling off into a mild world, although still hotter than today)
How did ocean currents help even out the temperature?
Currents move heat from equator to poles
_____ ______ affects how water delivers heat from place to place
plate tectonics
About Australia:
1. the position of Australia brings ____ _____ to Antarctica
2. Modern world: (far/close) to Antartica
3. Early Cenozoic: (far/close) to Antartica
- warm water
- far
- close (basically the last pair of continents from Pangea to split up)
What caused Antarctica to become colder during the Cenozoic era?
As Australia and Antarctica moved apart, it isolated Antarctica.
Cold currents isolate Antarctica from warming influences; the Antarctic Circumpolar Current
a current that circles around the South Pole; trapped in an endless loop of cold water around the south pole.
Antarctic Circumpolar Current
how much something reflects sunlight
albedo
How does albedo affect the global climate?
- Ice reflects more sunlight (has a high albedo), which cools the climate
- Trees, asphalt, etc. have a low albedo, which traps more sunlight and turns into heat instead
Changes in ice cover change _______, which change ice cover even more.
Result: creates runaway _____ of cooling or warming:
temperatures; cycles
What is the Cooling Cycle?
more ice → high albedo → cooler air. (then it circles back to more ice again)
What is the Warming Cycle?
less ice → lower albedo → warmer air. (then it circles back to less ice again)
More ice causes a (pretty stable/unstable) climate. This is how it was in what era?
unstable; Mid-Cenozoic era (quick climate changes; hot cold hot cold and so on)
Less ice causes a (pretty stable/unstable) climate.
pretty stable
How do ocean temperatures affect evaporation?
Warmer water means more rain
Warm climate = (more/less) rainfall, more (rainforests/grasslands)
more rainfall, more rainforests
Cool climate = (more/less) rainfall, more (rainforests/grasslands)
less rainfall, more grasslands
What causes grasslands to become more common in the late Cenozoic?
Cooling in the Mid-Cenozoic causes grasslands to spread. (cooler, drier climate)
When did grasslands begin to spread?
late Cenozoic era
How did animals such as horses change to fit this new environment of grasslands? (2)
- Longer legs for running
- Larger teeth for eating tough grasses
What was the perfect late Cenozoic animal (thrived in grasslands)?
Rodent
_____ ______ in Neogene = grasslands
Great Plains
In what period did the Ice Ages (or Ice Ages) occur?
Quaternary period
What was the climate like in the Quaternary period?
- repeated cycles of cooling and warming during the Ice Age
- cycles of falling and rising sea level
What period of the geologic time scale are we in today?
Quaternary
Quaternary period includes what two things?
- Ice Age
- Modern World
In the Quaternary, average temperatures are much (hotter, colder) than today.
colder
T or F: The climate was cold all throughout the Quaternary period.
False; several times the temp spiked back up; sometimes there were short, warm times
The warming-cooling cycles of the Quaternary are ____ _______ years long.
100 thousand (happens every 100 thousand years)
Each warming-cooling cycle has a (fast/long) cooling off time. Then there is a much (slower/faster) warming time (because of ____ _____)
long; faster; ice melting
What do we call the warmer and colder times during the Ice Age?
(Warming-cooling cycles)
- Warmer times = interglacials
- Colder times = glacials
How are Milankovitch cycles related to these repeated cycles of climate change?
Changes in Earth’s orbit and tilt affect global temperature and amount of ice.
The Last Glacial Maximum happened ________ years ago. Continents have (extremely/barely) moved since then.
18,000; barely
During the Last Glacial Maximum, PARTS of what 3 places were frozen?
North America, Europe, and Asia
During the Last Glacial Maximum, _______ was practically totally under ice.
Canada
T or F: the whole world was frozen during the Ice Age event.
False; not like the Snowball Earth event
For animals that lived in the (Southern/Northern) part of North America during the Ice Age event, there was a big climatic disruption.
Northern
How much of North America was under ice during the Ice Age?
Around half the continent– the Northern part of North America
What clues show how much land was under ice?
moraines
hills of sediment that outline glaciers (found at the end of a glacier)
moraines
Moraines are good for ______. Why?
farming; great soil with lots of nutrients released
What happened to the sea level during the Ice Age?
sea level dropped (more ice on land = less water in the ocean)
Sea level (rises/falls) when glaciers grow, (rises/falls) when they melt
falls; rises
During the Quaternary period, there were most (high/low) sea levels.
low
T or F: At the last glacial maximum,
the sea level was much lower than today; ____ feet or ____ meters lower
True; 400; 120
What did the Gulf Coast of North America look like during the Ice Age?
Lower sea levels caused more land to be exposed; Gulf Coast shoreline extended much farther out than it does today.
large animals (like mastodons) that went extinct by the end of the last glacial
megafauna (ice age time)
Describe the features of a wooly mammoth:
1. Teeth?
2. What they ate?
3. Habitat?
- Flat teeth with ridges
- Plant eating (grass)
- Tundra
Describe the features of a mastodon:
1. Teeth?
2. What they ate?
3. Habitat?
- Teeth with high peaks
- Plant eating but NOT grass
- Forests
Wooly mammoths and mastodons are differentiated by their ______.
Teeth
Which animal lived in Alabama? Mastodons or wooly mammoths?
Mastodons
