SNOWBALL EARTH Flashcards
What are Milankovich cycles?
Natural cycles where the Earth is further away from the sun and tilting at a different axis
What is the cryosphere?
The frozen aspects of the earth
5 examples of the cryosphere
Snow
Sea ice
Ice caps
Glaciers
Ice sheets
Permafrost
How does sea ice form?
Ocean surface freezes, pushing out salt
Salt is denser and sinks, forcing water to move
Thermohaline circulation
What is albedo?
The reflectivity of the Earth’s surface
Snow has a high albedo
What is IRD?
Ice-rafter debree that provides evidence of large-scale glaciation
What are dropstones?
Stones carried by glaciers that don’t match the surrounding geology
What do dropstones tell us?
That glaciers extended down to the ocean
When did snowball Earth occur?
850-635ma
What evidence do we have for snowball Earth?
Dropstones in Australia
What is paleolatitude?
The former latitude of the continents, can be measured with the magnetic properties of rock
