Climate Change Research and Measuring the Amount of Ice in the Alaska Range

Editor’s Note:  This is the first in a series of blog posts from UMaine’s Climate Change Institute, which is currently conducting fieldwork in the Alaska Range. Seth Campbell, a University of Maine graduate student pursuing his Ph.D. through UMaine’s Climate Change Institute and Department of Earth Sciences, is getting ready to lead an expedition in Denali National Park in Alaska. This will be his fifth field season in Denali.

I am in Alaska already working on a couple of different projects I’m involved with before I go into the field for the Denali project on April 21. We have quite a team this year to help in the field research including myself; UMaine undergraduate Josh Plourde; former UMaine students Curtis Marston and Lyndsay Marston; Kristin Schild, who earned her master’s degree at UMaine’s Climate Change Institute and is now working on a Ph.D. in earth sciences at Dartmouth; Brad Markle: A Ph.D. student in glaciology student at the University of Washington; Dave Silverstone, an undergraduate student at the University of Alaska Anchorage; Adam Toolanen, an undergraduate student at Lund University in Sweden; and Hazel Shapiro, an undergraduate student at Dartmouth.

The most exciting news recently is that a the proposal submitted to the National Science Foundation by Dr. Erich Osterberg (Dartmouth), Dr. Karl Kreutz (UMaine), and Dr. Cameron Wake (University of New Hampshire) was funded to start ice core drilling on Mount Hunter, Alaska, beginning in the spring-summer of 2013. This proposal is many years in the making for Karl, Cameron and Erich, including the past four years with dozens of people helping either in the field or processing samples and data back at UMaine, Dartmouth, or UNH. Although the drilling doesn’t start until 2013, we still need to download meteorological data from a station we installed on the Kahiltna Glacier in 2008. The station records such details as hourly temperature, humidity and precipitation, which are useful for comparison to the ice core once we actually extract it for chemical analyses.

Beyond the recently funded NSF proposal and downloading the meteorological data, this year’s field team is helping me with a different task of estimating total ice volume in the Alaska Range. We will be using ice-penetrating radar to measure ice depths on the Traleika, Muldrow, Kahiltna, and Ruth glaciers between April 21 and May 31. This ice depth data from a select few glaciers will be used to test or improve a numerical calculation that relates ice depth to glacier surface area, a method known as area-volume scaling. We hope to use this mathematical relationship developed from a few glaciers to calculate the total ice volume retained in the dozens of glaciers situated in the Alaska Range.

To collect the ice depth data we tow an ice-penetrating radar system behind us while we ski on each glacier. We ski from remote camp to remote camp, setting up tents at the end of each day. The complete radar system that we use includes an antenna transmitter that sends electromagnetic (EM) pulses through the ice and an antenna receiver that receives the reflection of each EM pulse from layers in the ice and bedrock under the ice. The antenna is connected by cable to a computer which records data about each EM pulse sent and received by the transmitter-receiver combination. We know how fast radio waves travel through ice.  Therefore, we can calculate how deep the ice at each location we measure if we record the time it takes for each radio wave pulse to return to the receiver after it is transmitted. The collection process required a team effort. We towed the antenna behind us while skiing at rates between 1-2 kilometers per hour (basically a slow walk). We travel slowly to improve the contact between the ice and the antenna which assures that the radar signal is sent into the ice. It is also hard work to tow the radar system!

The work can be exhausting and challenging physically (and emotionally on some days), and the day doesn’t end after the daily field science work is completed. At the end of the day we spend several hours setting up tents, melting snow for water, cooking food, charging batteries with solar power equipment and preparing for the next day. That said, we are lucky enough to work in one of the most amazing mountain ranges in the world. With mountains more than two miles high towering above us, the scenery can’t be beat.

We have divided this season into three mini-seasons because our team members are staggering their visits to the glacier. Between April 21-29, Curtis, Lyndsey and I will be collecting ice depth data on the Traleika and Muldrow Glaciers.

Between April 29 and May 15 we will collect data on the Kahiltna Glacier with new team members Dave, Adam and Brad. On May 15 our final field team shows up and some team members depart.  We will then either finish field activities on the Kahiltna Glacier or fly to the Ruth Glacier for two more weeks of ice data collection before we end the season.