Monday, August 17, 2015

Taku Glacier drilling

We just got back from Taku Glacier, one of the few remaining advancing glaciers in the world, where we study the motion of the glacier, both ice deformation and how it moves over the bottom; and how this changes seasonally. We also look at how the glacier deforms proglacial sediments and erodes its base. To do this, we use a whole range of glaciological measurements, including surveys with GPS, radar, active and passive seismics, borehole invetigations, timelapse cameras, stream measurements and dye tracing tests. All of this activity sure made for an interesting field camp with up to 13 people there at times.

Below some pictures from the field work in no particular order.

Chris and Dale and I are installing a new instrument we developed: an instrumented subglacial dragspool that measures ice and till deformation, water pressures and sliding of ice over till.

The drill camp on a nice day.

A moulin that conducts water from the surface to the bottom of the glacier.

The daily commute from the drill site to the camp at the front of the glacier.

A nice evening at camp.
Near the glacier front.

Looking out over the Taku River and Taku Inlet. Everything in this image was at least 100 m deep ocean about 100 years ago.

The glacier terminus.

The main glacier outflow on the eastern glacier side.

The glacier terminus.

The glacier advances in winter and spring and then retreats in the summer because of the very high melt rates, leaving push moraines behind.

Here the glacier advanced across the Norris River last winter and has now retreated again.

Taku Glacier used to calve into tidewater. Now the only calving happens into a small section of the Norris River.

Two ice marginal lakes on the Norris River drained while we were in the field. We noticed the very high stage of the river and got to see the cause on the flight back to Juneau.