14 January 2013
CReSIS camp, Antarctica
A belated happy new year to you all! On New Year's Day we set out from CReSIS camp toward the Transantarctic Mountains. It was slow going with all of our camp gear and some of our science gear, and we arrived late in the evening to our chosen patch of ice.
From the cleanest, whitest slate we began constructing our town, equipped with a kitchen tent (yellow above), science tent (red and blue above), bathroom (read: hole with a tent overhead, orange above), mountain tents for sleeping, and a few pee flags. Most of our time at camp is spent in the kitchen tent, where we spend a lot of time melting drinking water from snow, eating and talking. The floor in the middle of the tent is compacting and melting at a greater rate than the rest, and chairs and
tables are starting to list toward the middle.
 |
| Just enough room for my sleeping bag and luggage. |
 |
| A bit of drifting around my mountain tent |
We have now been out in the field two weeks. We have visited the seismometers we left on the ice last year and collected the data. The data does show the slip events that we hope to study further and has some interesting patterns associated with different stages of these slip events. Grace is using this data to design a distribution of seismometers that will allow us to constrain the geometry of the sticky spot at the ice-bed interface. We are installing seismometers in these new locations. The sensor itself is buried several feet below the surface to get better coupling to the snow and to increase the odds that it will remain level through the year. After placing the sensor we test the reception on three
channels corresponding to three axes oriented vertically, north-south and east-west by jumping up and down. Neil, Grace and Doug are also using active seismics, creating a wave by hitting the ice with a mallet, targeting the regions with a lot of seismic noise. The reflection from the bed should give us information about the characteristics of the bed surface. This season the CReSIS team collected airborne radar data on the Whillans Ice Stream that will show internal ice layers and the ice-bed interface when it is processed.
We took a trip out to Subglacial Lake Mercer, another one of the lakes in this regional hydrologic system that has been active in the past decade. GPS stations have been collecting data there for the past two years. Matt, Slawek and I travelled there to service the stations, installing new turbines on one of them and removing another (see photo). The one we moved will help us calibrate the GPS measurements we will be taking at locations in a grid once this season and once next season to measure a year of movement over the sticky spots and at the grounding zone.
The traverse has arrived at CReSIS camp with our equipment, and they will be heading straight to the site of the first borehole we will drill this season. We traveled to CReSIS camp to meet the traverse and welcome Susan Schwartz and Dan Sampson from UC Santa Cruz and the drillers, who arrived
by plane. We are very excited to start this new phase of the project. We said good-bye to Doug Bloomquist, who has been a huge help in getting the seismometers installed and running. While we are here, Slawek collected distributed temperature measurements down the hole from the surface to
Subglacial Lake Whillans. The sensor string was lowered into the hole last season and is now completely frozen into the ice. Today we leave by skidoos with Susan and Dan for our camp, which will pack up and move closer to the drill site. This morning I awoke to a fog that wipes out
the horizon completely. I hope we get better visibility soon so that our newcomers can enjoy a view of the mountains on our journey. Here's to smooth travels! Off to loading sleds -
No comments:
Post a Comment