Let’s Talk Science: Ice Streams
02-07-2018
Category: Scientific Work
Welcome to our blog series, “Let’s Talk Science,” where we break down the science behind our team’s work. Last week, we talked about nunataks (rock that is exposed when the ice moves). This week, we’re sharing one way the ice moves and allows those nunataks to become exposed.
In some places, glaciers move and change really slowly. In other places, the ice moves much, much faster. The fast-moving areas of ice within an ice sheet are called ice streams.
Ice streams move faster than surrounding ice because the bottom of the glacier in this area has lots of water and soft sediment (ground up rocks or mud), and sometimes the bottom of the glacier is much deeper.
In the picture above, you can see the ice stream between the two ridges. Dr. Jon Harbor, the photographer, is standing on one of those ridges.
Did you ever go to the beach as a kid? My family did. My brothers and I had to hold my parents’ hands as we walked towards the ocean, but they were moving so slow! So instead, we let go and ran as fast as we could to the water.
In a way, ice streams are like excited kids at a beach. They move to the ocean much faster than the “adult glaciers” around them.
Check out this video from our friends at NASA:
In the video, you can see the ice streams in the blue and purple colors. In this kind of map, they look like water, don’t they?
Even though ice streams are moving faster than the rest of the ice, an ice stream usually only moves about 1 km (about 3,000 ft) per year. Many people can walk that far in ten minutes!
Even so, ice streams are important to our team. Often, ice streams are long depressions in the ice surface, and it is around these that we can find most of the valuable nunataks. But the team has to be careful! Crevasses, or giant cracks in the ice, form along an ice stream. You wouldn’t want to run off and fall into one of those!
Got a science question for us? Leave it here and we can answer it for you. Maybe we’ll even feature it in our blog!
#IceStream #LetsTalkScience #Mapping