Posts tagged "ice age"

Antarctic expedition to estimate thinning ice sheets

Antarctica might seem like a desolate and inhabitable continent with little to offer other than perhaps the sight of penguins, but it holds the answers to many scientific questions. Simply put, Antarctica is covered by kilometers-thick ice, frozen water which will melt when sufficiently warmed. Sea level around the world is therefore dependent on how fast Antarctica’s ice sheets melt. My research looks at past changes of ice sheet thickness. As a glacier melts and thins, rocks on its flanks become exposed to the atmosphere (specifically cosmic radiation). A technique called surface-exposure-dating is used to estimate when rocks became exposed at the glacier surface, creating...

Extinction: the changing face of the biosphere

In the Earth’s 4.6 billion year history, over 99% of all the species that have ever existed have become extinct. In the majority of cases, these extinctions are due to competition between species for space, food, or other resources; or that a species did not adapt sufficiently or quickly enough to changes in the environment. Extinction is a natural and on-going part of the biosphere’s engineering that continues at a background rate. This constant cycle of extinction, adaptation, and evolution means that as one species meets its demise, another will take its ecological niche. Over long time periods (thousands or millions of years), this can...