Image of the Day
Success in the Field!
Mission accomplished for the WISSARD team, all shown here. Four holes drilled, and seismic, tilt, and temperature equipment deployed. They have packed up equipment and traversed back to the Subglacial Lake Whillans site, where they are packing and winterizing additional equipment. The whole team will fly to McMurdo in the next few days, followed by the 3-member traverse team, which will make the ~12 day trek. Image by Chad Carpenter, who used a timer and slid into place laying down in the front just in time. His antics made Graham, left, and Dan, right, laugh and even got Dennis to smile. Check out the TransAntarctic Mountains, behind. Beautiful. Job well done!
January 7th, 2013
WISSARD-Lite is how our project is being referred to this year. The 2013-2014 field season for the WISSARD project was downsized following the unfortunate timing of the government shutdown in October of 2013. As a result, drilling at the grounding zone embayment to continue biological, geological and chemical exploration where the outflow of Subglacial Lake Whillans meets the ocean has been postponed. We are very optimistic that WISSARD will return to Antarctica in 2014-15 to complete the original science objectives.
The WISSARD-Lite drill team is operating a smaller roving drill which will enable the geophysics team to travel to two sites within 50 and 100 kilometers from the 2012-2013 Lake Whillans site. At each site, two 15 cm diameter holes will be drilled, using the hot water roving drill, to a depth of 750 meters. Seismic, tilt and heat sensors will be deployed into the holes, and left in the ice to collect long term data. Because the ice stream will not be breached the team does not have to employ the clean access technologies used during the 2012-2013 season.
Eight WISSARD scientists have deployed to Antarctica this season from the University of California, Santa Cruz, and the Scripps Institution of Oceanography, along with five drillers from the ANDRILL Science Office at the University of Nebraska. The drillers have worked persistently in McMurdo since November preparing the roving drill (formerly called the Cal-Tech drill) for its traverse ride to the SLW area and the drilling operations. Four staff from ASC, the NSF-support contractor, are supporting science efforts through the coordination of logistics and the close to 1000 km traverse to move the supplies, and drilling and science equipment from the McMurdo Station to the study sites on the Whillans Ice Stream.
As of today, the WISSARD-Lite Traverse is almost there! Their position: S84 19.934' W169 08.026' with only 114 remaining miles. If all goes well, the traverse will rendezvous with the WISSARD Science Team within the next few days. They will set up the initial drill site shortly thereafter. We are excited to hear the positive news from the field.
In the meantime, the science team has been busy at the CReSIS camp unpacking gear and preparing for the arrival of the traverse. They have performed an active-source seismic reflection survey using a sledgehammer on a plate of steel as the source of seismic waves, thereby testing the seismic receivers frozen into the SLW borehole last season AND one surface seismic unit. These tests were very successful in determining the systems have been functioning as planned.
More detail on the science team and the work they are accomplishing this season is available on the Science Reports section of this webpage.
WISSARD Project Overview
Subglacial Aquatic Environments
Over the last several decades, by using ground penetrating radar and other remote sensing tools, scientists have discovered that under the massive Antarctic ice sheets there lies a vast hydrological system of liquid water. This water exists because geothermal heat flow from below, coupled with pressure, movement, and the insulating nature of the ice sheet above, is great enough to maintain some areas at the base of the ice sheet above the freezing point, even in the extreme cold of Antarctica. In topographic depressions there are hundreds of lakes, both large and small; some are isolated, but many are interconnected by water channels and large areas of saturated sediments, the water eventually running out into the Southern Ocean as the ice sheet becomes a floating ice shelf.
In order to explore one of these hydrological systems at the margin of the West Antarctic Ice Sheet, we have organized an interdisciplinary project to access the subglacial environment. The Whillans Ice Stream Subglacial Access Research Drilling project (WISSARD) is using a variety of tools and techniques to explore Subglacial Lake Whillans and the nearby grounding zone, on the southeastern edge of the Ross Sea. Radar and seismic equipment is used to profile the overlying ice sheet and the underlying water, sediments, and rock, while GPS stations accurately track ice movement.
Continued geophysical surveying is the focus of the 2013-2014 season. Two sites on the Whillans Ice Stream will be investigated. At each site a mobile, hot water drill will be used to create 15 cm holes, 750 meters in depth where borehole sesimic, tilt, and heat sensors will be deployed and left to collect long-term data. Surface seismic sensors will also be installed, to add to the network of GPS and active seismic stations monitored on the surface of the ice stream to help characterize the movement of ice and the conditions of the ice at the base of the ice stream.