Thursday, October 20, 2016

The end of Taku

Ok, so it's not the end of Taku Glacier. Actually the glacier is still doing quite well. But it's the end of our 3-year NSF funded project. On one of the most beautiful days I've ever seen in Southeast Alaska, we flew to the glacier and dismantled all remaining equipment, such as GPS, seismic stations, cameras, and borehole data loggers.
Now it's back to the office and the work of data analysis, paper writing and conference presentations starts. We had a very productive meeting of the whole science team shortly after returning from the glacier.
Here are some pictures from this beautiful day:
The glacier just upstream of the terminus. Most of this ice would not have been visible around 1850, when this glacier was retreated.

Doug and I are dismantling a GPS station while the helicopter is waiting for us.

This GPS was just spared a detrimental crevasse fall.

The glacier advancing onto its own sediment delta. The sediments are protecting it from the ocean and thus from losing ice through calving.

On the way back we got a nice view of Lemon Creek Glacier. This glacier has been monitored since the 1950s, but it's not doing so well this year. There is essentially no snow left on the glacier this fall.

Thursday, September 8, 2016

Operation IceBridge Alaska: August campaign

Twice a year (in May and August) I am part of a NASA funded team to survey as many glaciers as we can with lasers and radar. We cover most of the glaciated parts of the State of Alaska and this always gives us a great view of these areas. Here are some impressions:

Nizina and Rohn Glacier in nice light

The Hole-In-The-Wall near Skolai Pass

I got the opportunity to fly to the White River Valley and look at a landslide that happened in Fall 2015 and was of very impressive dimensions. It turns out that the day before we flew there, some National Park employees had witnessed another landslide that resulted from the collapse of a hanging glacier.

This shows Mt. Sulzer with the break-out area. The fresh landslide is a mixture of ice and debris. The much wider debris covered area is from an enormous slide that occurred last fall.

The landslide originated from the collapse of the hanging glacier on the right side of the picture.

Last fall's landslide ranged many kilometers into the creek delta and mowed down every tree in its way.

Right next to the landslide we found a small but vigorously surging glacier

Many glaciers in the Chugach Mountains have almost no snow left in August. Not a good sign for glaciers!

Some freshly calved blue ice at Columbia Glacier

A view down the West branch of Columbia Glacier. It is hard to believe that these glaciers were still joined just a few years ago.

Another glacier with very little snow left. It also nicely shows its layered structure

Mt. Logan: Always impressive

Here was a surprise: One branch of the Miles Glacier (flows into the Copper River) is surging. The surge margins are clearly visible here.

And another mixed ice/rock fall.

Tuesday, July 12, 2016

Taku Glacier and the Juneau Icefield Research Program

Last week we finished some of the last work on Taku Glacier under our current NSF grant. We serviced all our borehole instruments that we installed last year; many of which are still working. We also ran a low frequency radar to measure the ice thickness. In the past, Taku had been excavating sediments at its base, so the glacier has been getting thicker, although the surface elevation barely changed. In some places this happened at rates of more than 3 m/yr!

Taku Glacier is an advancing glacier, but over the past two years it has been retreating slightly. This is probably still an after-effect of the very warm winter 2014/15, when no snow fell on the lower glacier. Consequently, last summer saw a big seasonal retreat, and this winter's advance could not compensate for that. It will be interesting what happens after this El Nino is over.

After Taku, I was invited to go to JIRP (Juneau Icefield Research Program) and give a lecture. This is an undergraduate research expedition that has been going on every year since the 1940s. I was very impressed by the program and the many smart and interested students, many of which had very little or no experience with snow and ice.

Doug is laying out radar antennas

Ice radar in crevassed areas
Nice evening light at our base camp

Base camp at sunset

JIRP Camp 17 at the top of Lemon Creek Glacier

The JIRP students are doing safety training on the glaciers. For some it was their first time on skis.

JIRPers at sunset

Sunday, June 19, 2016

The 4th International Glaciological Summer School in McCarthy

We're just back from an International Summer School that we organize every other year. 28 graduate students from all over the world came to McCarthy, Alaska, to hear lectures about glaciology, show their research to peers and work on projects. We also did two glacier hikes, and many took the opportunity to see this fantastic landscape from the air.
This is the fourth time we did this, and this was the luckiest we've been with weather: all but one day were blue sky with amazing views of the Kennicott Glacier and the phenomenal Stairway Icefall.

The Root Glacier with the amazing Stairway Icefall.

Mike Loso is explaining the local glaciology to the summer school students
A river on the glacier


Inside a glacier cave.

Tuesday, June 14, 2016

The Tyndall tsunami

In October 2015, a large rockfall was released near the terminus of Tyndall Glacier in Icy Bay.
The rockfall grazed over the lower part of the glacier and then fell into the ocean creating one of the largest tsunamis ever recorded. At its highest point, the wave reached about 180 m a.s.l.!

The break-out area is to the left of the glacier. It scraped off the surface of the lower part of the glacier

The wave cleared the entire shore line of trees.

The trees are all pointing into the fjord implying that it was the outgoing wave that caused most of the destruction.

The tsunami destruction is clearly visible along the entire side of the fjord.

Saturday, May 21, 2016

Surging glaciers everywhere

The glaciers in the Kluane National Park, right across the border from Alaska are particularly active this year and we have been able to observe several of them. Glacier surges are spectacular. When they occur the glacier can move at up to one hundred times its normal speed and in the process most of the glacier surface becomes extremely crevassed and distorted beyond recognition. Below are some pictures. Unfortunately, they didn't turn out very sharp through the airplane windows.

The Steel Glacier is undergoing the most vigorous surge:

On the upper glacier, the ice surface has dropped be several tens of meters, leaving behind a "bathtub ring" of stranded ice.

The fast flow creates very crevassed shear margins

The Walsh Glacier is also surging. I think it's in its third year of surging now, but this is by far the most active I've seen it:

And finally a picture of Fisher Glacier. This surge might be done; it reached all the way to the glacier front.

Monday, May 16, 2016

Operation IceBridge: The Stikine Ice Field

One of the most amazing things I get to do as a glaciologist is to help survey many or Alaska's glaciers from the air, as part of NASA's Operation IceBridge. This spring we have a big program and we started at the very southern end of the state: The Stikine Ice Field. Below are some impressions.

We based our flights out of Petersburg, Alaska; one of the most picturesque places in the state. In the background, the ice field with its most prominent mountain, the Devil's Thumb, is recognizable.

The best-known glacier of the ice field is LeConte Glacier, the southernmost tidewater glacier in the northern hemisphere:

Adjacent to LeConte Glacier is Baird Glacier. Until last year, it was a land-terminating glacier. But then a big subglacial flood floated the terminus and now the glacier ends in a lake. It looks like it might be retreating for a while.

 The flood on the Baird came out of a weirdly amazing place: The Witche's Cauldron. It's in the picture below, the area in front of Devil's Thumb. A big subglacial lake forms in the cauldron and then catastrophically releases along the Baird Glacier.

On the way home we passed the Juneau Ice Field. Here is a nice shot of the Hole-In-The-Wall Glacier (on the right) and Taku Glacier (on the left). Both are advancing glaciers. The Hole-In-The-Wall Glacier didn't even exist 150 years ago, it only formed when the Taku Glacier readvanced and spilled over.

And, finally, here is our science platform. The Single Otter, piloted by famous bush pilot Paul Claus