2 holes drilled

19 January 2014
Site 1B, Whillans Ice Stream, Antarctica

The traverse is off!

We did have flat light for our journey out to the first borehole location but the journey went fairly smoothly with a few adjustments to our sled loads.

A mid-journey break

The scientists on skidoos and the drillers on the traverse pulled up to the location which would be the site of our first borehole. It was marked by a seismic station, on the surface a box and solar panel, which looked miniscule by comparison with the large tractors and the wide ruts they made in the soft snow. The drillers got right to work and by lunchtime the next day the hole was finished. We found out the approximate thickness of the ice from the CReSIS team based on the raw data from this year's survey so that we could avoid entering the subglacial environment, not being equipped with clean access technology as we were last year.

Drill Site 1

Water hose rigged for drilling

The depth of this hole was 690 meters and took about 12 hours to drill. The drill uses hot water to melt the ice. At its maximum speed, it melts the hole at 1 meters per minute and exits the hole at a rate of 2 meters per minute, also pumping hot water to keep it open. The hole ends up 0.8 meters across.

Tiltmeter above seispod about to go down the hole.

My job for part of the deployment was to
ziptie the cables together as we put them
down the hole.

Then us scientists set up reels of cables to send our equipment down the hole. This equipment includes small seismic sensors, and distributed tilt meters. These all went down the hole simultaneously, taping the cables together as we went. All of our equipment was in by dinner and so far everything is running as it should. We are all happy with this success.

Bulldozer pushing snow into the hot water tank.

We repeated the process at the second hole, which is located a little more than a kilometer from the first hole. At this distance, we think that both sensors will be able to detect some of the same seismic events. Both of these boreholes lie within the zone of high seismic noise we detected over the course of last year, indicating sticky motion of the ice over its bed. This time, we sent down distributed temperature sensors in addition to the instruments used at the last hole. When we had deployed about 300 meters of cable some bit of the cable got caught on the wall of the hole. We tried raising and lowering the cable a few meters to get past but we soon found that the cable was frozen at that point, for it took a lot of force to turn the reel. We would have liked to get closer to the bed, but we still expect to get a better seismic signal of the stick-slip motion at half the ice thickness than at the surface.

Me with the GPS receiver.

Today Slawek and I took static GPS measurements in a line perpendicular to
the flow of the Whillans Ice Stream with subglacial Lake 7 at one end and stretching across the seismic array within which we have been drilling. We set flags in the locations of our measurements so we can return next year and see how far the ice has moved. We expect we might see the sticky spot slowing down ice flow.




Tomorrow we travel forty kilometers to the grounding zone, where we will drill two more holes. I'm excited to go to a new location for the last 11 days of the project.