The last week of August we returned to Black Rapids for the last time this season. The purpose of this trip was to winterize the 3 continuous gps stations and disconnect their solar panels. Soon there will be almost no Sun in this part of the world, so they won’t do much good anyway. We also removed the 4 seasonal gps stations, removed the batteries from three time-lapse cameras, and measured the locations of a few mass-balance stakes so that we can estimate the velocities further upstream on the glacier where there are no gps stations.
Since it is nearing winter on the glacier, we had to travel by helicopter so that we could land in a variety of different conditions. This was my first time in a helicopter and I’ll say that it was quite fun. Not only fun, but really efficient. We could land almost on top of every site we needed to visit. I would probably use them all the time if they weren’t so expensive.
Here are a few pictures:
Alright, we’re almost to the interesting part . . . but first look at what we awoke to on the second day:
Snow! Lot’s of snow on August 28th and not even at a very high elevation. The weather wasn’t looking much better, but once again, at about noon we gave it another shot.
We once again fly over the nasty looking lower part of the Black Rapids. The cloud ceiling was still too low to make it all the way up, but it looked better than the day before. So instead of turning back, our pilot set the helicopter down in a nice spot where we could just wait and see what happened. Here is some of that awesome terrain on the way up:
We had a phenomenal view of the landslides from the helicopter. These were enormous rock avalanches that occurred in 2002 after a 7.9 magnitude earthquake on the Denali fault (runs on the south side of the glacier). The debris crossed the entire mile-width of the glacier. This debris insulates the ice underneath, protecting it from melt.
After a short wait we finally found science!
The winterization of the Loket station went smoothly and the weather kept getting better and better.
On to the base station!
Our base station is on bedrock, so that it is stationary in relation to the GPS on the moving ice. It’s also trickier to find a good place to land the helicopter. When we installed it in the spring we just skied up the hill. Luckily, our awesome pilot made it so we didn’t have to walk far on loose talus slopes.
Another successful winterization.
What a great little pond!
And what a great view across the Loket tributary!
Now we have a hop, skip, and a jump to pick up the batteries and memory cards from our three time-lapse cameras. Much scenery along the way:
Our time-lapse cameras monitor lakes that fill every spring and drain every summer. When they drain, the increased water pressure at the bottom of the glacier lifts the mass of ice a bit allowing it to move faster. We want to see how much each drainage effects the motion of the glacier.
Then on to the other two cameras:
Now it’s 4:30 in the afternoon and we need to remove four of the summer-only GPS stations. This ends up going a lot faster and easier than we had hoped. All we needed to do was measure the antenna heights and pull out the stations. But, weight was becoming an issue, so in the end we split up. I flew with the pilot to pick up the last of the gear at the main station on Black Rapids while Martin walked down to remove the last two GPS stations on the lower end of the Loket tributary and main branch.
The flight out was filled with stunning afternoon light.
By the end of the day we had completed all of our primary objectives. With one more day of flying we were able to make a few additional measurements high up on the glacier that will help us determine the velocity of the glacier in the upper region as well. This didn’t require heavy equipment, just a GPS to sit and grab our location at some stake sites, so it was a pretty quick trip in the morning. Pretty day.
And that is the end of our first successful field season for this project!