Mind map
Snowball Earth
Map content
Snowball Earth
Evidence
- Ancient glaciers were discovered inside the tropics.
- The sea bed here contains sediemtary structures that can only be created by glaciers.
- Ancient glaciers were discovered inside the tropics.
Doubted because of the runaway freeze theory.
- This states that a certain amount of the earth was covered in ice, high albedos would cause the ice to constantly multiply, meaning that there was no way back from snowball earth.
- Albedos rate the reflectiveness of surfaces in a percentages, snow has one of the highest albedos at 85%.
- This problem was avoided when it was realised that increased CO2 levels had led to the demise of snowball earth.
- Increased amounts of volcano eruptions mean that huge amounts of CO2 entered the atmosphere, creating an ultra greenhouse effect.
- Carbon from the sea sediment was also released to increase CO2 levels.
- This states that a certain amount of the earth was covered in ice, high albedos would cause the ice to constantly multiply, meaning that there was no way back from snowball earth.