Climatology Flashcards
Glaciations
period of time when continental ice sheets increase in size and flow outward covering large portions of continents.
- 2 major continental ice sheets.
The Wisconsin Glaciation
Most recent, 75 000 years ago to approximately 11 000 years ago. continental ice sheets covered large areas of North America and Eurasia.
Glacial Erratics
rocks carried by glaciers and then deposited when the glacier melts. Ex) Jasper National Park to its present location near Okotoks,
U-shaped Valleys
Some glaciers carve out U-shaped valleys as they flow over Earth’s surface.
Ice Core Data
Drilled from ice sheets to study Earth’s past climate.
Annual snow layers are compressed into ice that contain tiny bubbles containing Earth’s ancient atmosphere.
Annual layers can be counted to determine the age of the ice.
Glacial Melt Patterns
Much of Alberta’s topography, including lakes and rivers, formed during the melting of the Laurentide ice sheet during the Wisconsin Glaciation.
Variations in Earth’s Orbit and Tilt
they yield a pattern that correlates to some degree with the repeated glaciations of the last two million years.
Solar Energy Output
Variations in solar output are believed to have an impact on global climate.
For example, a cold period from 1645 to 1715 of slightly lower solar output.
Moving Landmasses
Repeated glaciations tend to occur when there are large land masses near or at the poles.
As snow and ice accumulate at the poles, more solar energy is reflected back to space, cooling Earth.
Volcanic Eruptions
Particles suspended in the atmosphere from volcanic eruptions reflect solar energy back into space, having a cooling effect on global climate.
Ocean Currents
Ocean currents transport heat from equatorial regions to polar regions.
encircles Antarctica reduces heat transfer to Antarctica resulting in larger ice masses that reflect solar energy to space.
Asteroid Impact
66 million years ago resulted in large concentrations of particulate matter in the atmosphere.
This likely had a cooling effect and contributed to mass extinction at the end of the Cretaceous period.
Atmospheric Composition
Carbon dioxide and methane are greenhouse gases.
Greenhouse gases are gases that absorb infrared radiation emitted by Earth.
