Interviews

In between ice ages

Dr. Sarah Bradley from Utrecht University studies the history and behaviour of ice sheets over the last interglacial, the period in between two ice ages. “This was a period where the sea level was at least six meters higher, but it wasn’t that much warmer.”

GlacierThe Eemian is a geological era that started about 130 thousand years ago and lasted for fifteen thousand years. This is a warmer period in between two ice ages, and is therefore called an interglacial. Dr. Sarah Bradley, a postdoc researcher at the Institute for Marine and Atmospheric research Utrecht (IMAU), simulates this period for the purpose of understanding a warming earth.

“I am looking at the history of past ice sheets over the Eemian”, says Sarah. “What is interesting about the Eemian is that it wasn’t that much warmer, but sea level was at least 6 metres higher than today. We assume ice sheets like Greenland and Antarctica were much smaller, because sea levels were higher, but we do not know by what extent. I would like to understand what drove the ice sheets to retreat under these conditions, and how the Greenland and Antarctic ice sheets interacted. Therefore I am using a recently developed model at IMAU to simulate both ice sheets and sea level change for this time period.”

“Reconstructing the past is important for the future”, Sarah concludes. “If Greenland or Antarctica melt, sea level rise will be variable across the globe. Some cities might flood, while at some cities the sea level will fall. Understanding what drove the ice-sheets in the past, will help us to understand what will happen in the future.”