Growing up I spent most summers playing in the creeks around my house in Santa Cruz, CA. The water flowing out of the ground and its connection to the water table fascinated me. I went to college and graduate school to study how fluids, like the water in the stream, flow and found out that glaciers are just large frozen streams. In my current research I study how liquid water flows within glacial ice.
This liquid water turns out to be very important in West Antarctic ice streams—regions of relatively fast flowing ice within the Antarctic ice sheet. Ice is melted at the edges of these ice streams due to friction—try rubbing your hands together and feel how they warm up. This water then trickles down to the bottom and soaks into the ground. As more water enters the soil, the strength decreases—compare bending a dry sponge to one filed with water, which is easier to bend? In other words, if more melted ice is generated at the edge of the ice stream, the strength of the soil is decreased and the ice stream can widen. However, as water collects under the ice, a channel of liquid water can form and drain the excess water. The soil then does not lose strength as fast. The width of an ice stream is then a competition between the water flowing into the soil, which decreases the strength, and the flow of water into drainage channels.
My fascination with creeks near my childhood home is carried over to the complex ice streams of Antarctica and the liquid water flowing within the ice. Moreover, these Antarctic ice streams are important features in the ice sheet—they are the freeways for ice to move from the interior of the ice sheet to the coast. Ice streams are also sensitive to climate warming in the sense that they will begin to flow faster and drain more ice from the interior of Antarctica. The interesting fluid physics and relevance to a changing climate are what make me passionate about studying ice streams.
– Colin, Harvard University, USA
