Position: PhD Student Research School of Earth Sciences the
Australian National University Area of study: Geophysics
Project: Ice sheet history of North America during the last
glaciation What does that mean? Many parts of the world at high
latitude, such as North America, were covered in thick sheets of
ice periodically during the past 2.5 million years. Ice grew and
retreated in these areas largely as a result of long term
changes in the earth’s orbit, which changed the duration of the
seasons, and as a result changed the distribution of
precipitation, and the balance between melting and accumulation
of snow. In North America, the ice sheet that covered most of
Canada and parts of the United States reached its maximum extent
about 20,000 years ago. After this, the ice started to melt, and
by 6000 years ago, was completely gone. When these ice sheets
existed, sea level dropped dramatically lower than present. The
weight of the ice sheet also pressed down on the land in North
America, and due to the viscous n