Thursday, June 8, 2017

How deep is the Bagley Icevalley?

We have been trying to measure the depth of the Bagley Ice Valley for years, using airborne radar. But it has been an enigma; we suspected because of its depth. Temperate ice (ice at its freezing point) contains water and that makes it really difficult for radar waves to penetrate. We had a chance to do a survey on the ground with a very low frequency system and it looks like this was successful. We are still working on the data, but it looks like we've found ice that is more than 1500 m thick.

Deployment by Ultima Thule's Single Otter

The front half of the radar setup with antenna and a sled containing the receiver

How far is it to bedrock? Photo: Jack Holt

Pulling the radar across the glacier. Michael on the snowmachine and I'm being pulled on skis. Photo: J. Holt

Wednesday, June 7, 2017

Black Rapids Glacier

Every year in spring we make a trip to Black Rapids to do some mass balance measurements. Once again we found a beautiful day for it, and this time my daughter Sonja got to join me as well.

Surprisingly, Black Rapids Glacier had quite a low snow year; it was one of the thinnest snow covers we've measured in several decades. It's surprising, because Fairbanks had quite a nice year. In general, Black Rapids Glacier continues to thin rapidly.




Tuesday, May 16, 2017

Glacier caves

I've been slacking with this blog. Here is a picture from a visit to Juneau during spring break. We got an opportunity to visit the glacier caves at Mendenhall Glacier. Amazing!


Wednesday, February 15, 2017

Drilling through the Nansen Ice Shelf

We just returned from the Nansen Ice Shelf, where we drilled two holes through 400 m of ice. We installed ocean instruments into the ocean cavity below the ice. A relatively new technique allows us to measure a continuous profile of ice and water temperatures with a fibre optics cable. All instruments are now read by an AMIGOS II station and data relayed to NSIDC in Boulder CO by Iridium modem. The station was built by Ronald Ross of Polar 66 and Ted Scambos of the University of Colorado, and Dale Pomraning and I were responsible for the hot water drilling.

A view down the Nansen Ice Shelf. The two islands in the shelf are Inexpressible Island in the distance and Vegetation Island. Inexpressible Island was the location where Scott's Northern Party spent a miserable and very windy winter dug into a snow cave. The reason for the name is that the actual names given by the surviving party where not fit to print.


Vegetation Island, named for the lichen that apparently grows there
Our camp cook tent

Master driller Dale

The hot water drill system with drill hose in the foreground, water basins, pump and heaters
Jin Suk, our Korean helper, finds hot water drilling very exciting!

The Eisenhower Range. Note the drifting snow plumes over the mountains.

Camp with impressive snow drifts in the background.
 This area is famous for extreme wind. We were lucky at our camp, but were surrounded by wind with some incredible amounts of snow drifts.


The valley in the center is filled by snow drifts that must be well over 100 m high.


One day a penguin decided to visit our camp and he stuck around for about 24 hours. The penguin was molding; during that time they cannot go in the water. Why they wander so far onto the iceshelf is anybody's guess.




During one night of drilling we were treated to a full moon rising in the midnight sun. 





The completed AMIGOS II station.

While we were drilling, other science activities occurred in this area. This is a helicopter with three booms that house radar antennas doing ice thickness surveys.

The Jang Bogo station on our return trip with the Campbell Ice Tongue and Mt. Melbourne in the background.

Wednesday, February 1, 2017

Jang Bogo Station

It's time again for a trip to the far south. This time our goal is to drill through the Nansen Iceshelf, which is a bit north of McMurdo. Together with Dale Pomraning and Ted Scambos and Ron Ross from Boulder we will install an AMIGOS station, which is a glorified weather station that also measures ocean properties below the ice. This program is in collaboration with the Korean Polar Research Institute (KOPRI). At the moment we are at the Korean station Jang Bogo. It is a brand new station, only completed in 2014. We arrived here a few days ago on the Korean icebreaker Araon after a relatively uneventful journey (that's a good thing!). In the last few days we have prepared all of our gear, which was shipped here ahead of time. Now we're ready to go drilling!

The Araon in port at Lyttleton, New Zealand

The Araon near Jang Bogo Station
Jang Bogo Station

The welcoming committee at Jang Bogo

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.