Module IX

Essential Question:
How are climate, terrestrial ice and Alaskan indigenous cultures all connected?

Living in Alaska one has many opportunities to explore the terrestrial ice portion of the cryosphere. Exit Glacier, a few miles outside of Seward, is a great spot to hike up to glacier, passing signs along the way that date the quick recession the glacier has experienced. You can hike along a trail up the side of the glacier to the Harding Ice Field, and if you enjoy sledding you can even bring along a garbage bag (light weight and easy to turn into a sled by making leg holes) and try out some of the little chutes on the way back down.


Many Alaskans depend on frozen lakes and rivers for transportation in the winter. My parents moved out to Flat Lake a few years ago, and drive over the Big Lake/Flat Lake ice road every day. They are some of the only permanent residents on the lake, and my father has a website on which he posts daily ice thickness and temperatures, as well as the latest accidents where brave individuals have driven through the channels and fallen through the ice!

Big Lake ice road - Larry Taylor 2010

When I was preparing to go back to school to be a teacher I took a few great classes on glaciers from UAA that I highly recommend. One of them was a week long class where we camped along the Kenai Peninsula and learned all about the last ice age observed the signs left over from it. My favorite part of that class was hiking up a little hill near Homer and learning that out of all of Southern Alaska it was the only point that hadn't been covered by ice fields: A tiny green island in a sea of white ice. The other class was a series of Saturdays where we met up around Anchorage and the Mat-Su valley and observed glaciers and landforms left by the last ice age. One day we got to hike around on the Matanuska glacier, which involved crawling through an icy tunnel to see an under-ice river and observing supra glacial lakes and forests. It was breathtaking.

A supraglacial Lake on the Bering Glacier

Living here I have always felt like the amount of water tied up in glaciers, ice fields, and permafrost was a tremendous amount, but when you look at the entire world's water budget you gain some perspective. Only 2.1% of water is found in glaciers, and 0.1% of the ice crystals in the world are in Alaska! Antarctica has a much larger percentage of those crystals (91.4%).



Areas of the Earth that have large ice shelves, such as Antarctica and Greenland, are important to the climate for many reasons. One of the major reasons is that the high albedo from the ice and new snow (it reflects 90% of the Sun's radiation) helps to keep Earth cool. Another reason is that when ice that is on land melts it raises sea level. If all of Antarctica melted it would raise sea level by a whopping 73 meters, which would make Atlantians out of millions if not billions of us. This lesson comparing sea ice to land ice showing the difference in sea level rise is a great one for students. Many of my students are from coastal regions of Alaska as well as the Phillipeans and Samoa, and understand how a small change in sea level can be catastrophic.

Antarctica is basically a frozen desert, and is the coldest, windiest, driest continent on earth with the highest average elevation. Because of the high albedo of ice and snow most of the solar radiation is reflected back into space, and due to it's latitude Antarctica doesn't get much solar radiation in the first place. In fact, at the moment I am writing this the temperature at the South Pole is an amazing -56 degrees Celsius!

It is important for Alaskan students to understand the Antarctic ecosystem because it is so similar to our recent (on the geologic time scale at least) past. We can learn a lot about the last ice age and what Alaska must have been like from studying the frozen continent. Also, by keeping track of the changes in ice depth, we can project the future rise in sea level. Students need to understand that this threat is very real, because most of the Earth's population lives near sea level. In Alaska and parts of Southeast Asia, as well as other locations across the globe, entire communities have already had to move upland to escape rising seas. Today's students will be the engineers and village elders of tomorrow that will make this eventuality possible.