Ice Ages & Climate
What term describes a long period of cold climate when glaciers expand over large areas of land?
ice age
What force causes glaciers to move downslope?
Gravity
What type of valley is carved by glaciers?
U-shaped valley
What term describes large animals that lived during the Ice Age, such as mammoths?
Megafauna
What natural hazard involves rapid movement of snow down a slope?
Avalanche
What gas is most often linked to changes in Earth’s temperature over long time scales?
Carbon dioxide (CO₂)
What process describes ice breaking off the end of a glacier into the ocean?
Calving
What landform marks the furthest advance of a glacier?
Terminal moraine
Name one adaptation that helped Ice Age megafauna survive cold climates.
Thick fur, fat layers, large body size
Why are avalanches more common on steep slopes than flat ground?
Gravity causes unstable snow to slide more easily on steep slopes
Why do scientists study past CO₂ levels when trying to understand Ice Age cycles?
Because changes in CO₂ are closely linked to temperature changes and glacier growth/retreat
Why do glaciers move more slowly than rivers, even though both transport material?
Ice deforms and flows slowly under its own weight, while water flows freely
Why are glacial valleys wider and flatter than river valleys?
Glaciers erode across their entire width, not just at the bottom
Why are megafauna often described as “keystone species”?
Because they had a large impact on ecosystems compared to their population size
How can layers of snow with different densities increase avalanche risk?
Weak layers can fail, causing upper layers to slide
During the last Ice Age, Earth’s climate alternated between colder and warmer periods. What are the warmer periods called?
interglacial periods
How does debris trapped in glacier ice increase the glacier’s ability to shape the land?
The debris acts like sandpaper, grinding and scraping rock beneath the glacier
What evidence on bedrock helps scientists determine the direction a glacier once moved?
glacial striations
How might the retreat of glaciers have changed food sources for megafauna?
Changing climates altered vegetation, reducing available food
Why are icebergs considered a hazard to ships?
Most of their mass is underwater and difficult to see
Explain why relatively small changes in temperature can lead to major changes in ice sheet size.
Small temperature changes affect snow accumulation and melting, which can cause glaciers to grow or shrink significantly over time
Predict how glacier movement would change if snowfall increased but temperatures stayed cold year-round.
Glaciers would likely grow and advance because accumulation would exceed melting
If you see a waterfall dropping from a side valley into a main valley, what glacial feature does this suggest, and why?
A hanging valley, because the side glacier eroded less deeply than the main glacier
Explain how both environmental change and human activity may have contributed to megafauna extinction.
Warming climates changed habitats while human hunting increased pressure on populations
Connect past Ice Age processes to a modern environmental concern involving ice.
Melting glaciers affect sea level
Reduced snowpack affects water supply
Ice loss changes ecosystems