Earth and Environmental Systems

What do you call the part of the Earth system that remains frozen all year long?
What is the main requirement to get a glacier, and how does this relate to the snowline?
The total accumulation of ice during the winter must be greater than the total amount of ablation in the summer
Ablation: melting and sublimating
What are the six fundamental types of glaciers listed in your book (this is a morphological classification)?
1. Cirque glaciers (bowl shaped)
2. Valley glaciers
3. Fjord glaciers (valley below sea level)
4. Ice Caps (small)
5. Ice Sheets (large)
6. Ice Shelves (sit on water)
In a thermal classification of glaciers, what are the two main types?
Warm (temperate, fast)
Cold (polar, frozen)
Know what mass balance on a glacier refers to, and how it relates to the accumulation zone, ablation zone, and equilibrium line on a glacier.
Accumulation – Ablation through a year
(October to October)
What are the two main ways that glaciers move?
Internal flow: ice crystals shear past each other
Basal Sliding: (warm) whole mass slides along bed
Know what causes a glacier to advance, retreat or remain stable, and know what direction the ice that makes up the glacier is moving in each case.
Stable – accumulation = ablation
Advancing – ablation accumulation
Ice always flows down hill!
What shape valley do glaciers form?
U Shaped
What effect does the melting of sea ice have on ocean levels?
What two aspects of sea ice need to be measured to know if it is truly is shrinking?
Area and thickness
What will the freezing and melting of sea ice do to the salinity of surface water?
Freeze- salinity increases
Melt- salinity decreases
Besides changing seawater salinity, what other affects does sea ice have on the Earth system?
Ice is reflective-keeps planet cool
Ice reduces evaporation
Ice allows migration routes for some organisms
What is the name of ground that is frozen all year long, and how could its melting affect the climate system?
When did the last ice age begin, and when did the last glaciation begin and end?
Ice age: 2mya to present
Glaciation: 75,000ya – 10,000ya
What are the three main ways to get an ice age on Earth?
Plate tectonics changing ocean circulation
Reduced green house gas in the atmosphere
Change in Earth’s orbit around the Sun (Milankovitch cycles)