Snowball Earth Albedo Effect

The initiation of a Snowball Earth, involves a cooling mechanism in which an increase in the Earth’s coverage of snow and ice occurs. As mentioned previously, an increase in ice and snow coverage would result in an increase in the reflected fraction of solar radiation known as albedo. Increase in albedo causes a positive feedback for cooling.. That means, if enough snow and ice accumulates, farther cooling would result accompanied with larger areas being covered with more and more ice, and so on. The equatorial distribution of continents assists the positive feedback by allowing ice to accumulate in the regions closer to the equator, where solar radiation is direct (Hyde et al, 2000). The positive feedback loop would eventually result in creation

As a result, less carbon dioxide is removed from the atmosphere resulting in greenhouse gases accumulation and thus, a negative feedback.

However, during the Cryogenian period, the earth continents were all at tropical latitudes which slowed down the effect of the negative feedback (Kirschvink, 2002).

5.1 Effect of frozen period on life

A global glaciations as tremendous as the one suggested by Snowball Earth theory, would logically eliminate any photosynthetic life on Earth, as a result of the drastically depletion of oxygen. However, it was observed that microfossils such as stromatolites and oncolites have proven that life at marine environments at least did not suffer any mass extinction. Surprisingly, life developed and survived the cold period (Corsetti et al 2003). Proponents suggest that life may have survived in several ways including:

1- In tropical areas, the day-time tropical sun or volcanic heat heated bare rocks creating temporary pools wich would freeze at sunset (McKay, 2000)

2- In Small oases of liquid water possibly found near hotspots (Hoffman,

Conclusion

In conclusion, it can be devised from the previously mentioned information, that the theory of snowball Earth is still surrounded by mystery. Evidence supporting the theory are unable to absolutely assert that the Earth was covered entirely with ice at some time of the geological scale. Moreover, perhaps the name of the theory itself “Snowball Earth” requires rethinking as the Earth was not just a white ball especially with the presence of regular active volcanoes. Thus, continuous effort and farther investigations must take place to solve the mystery of such