Last science stop completed
Last evening, we finished packing our sleds at Site 7, and headed north towards the ice shelf at Fimbulisen. Site 7 was our last science stop, and we spent five days here on a variety of projects.
Location: Terningskarvet, 72º 15’ S, 2º 53’ E, 2400 metres a.s.l.
Weather: Clear, -24 C, wind 4 kts
Actually, the first major accomplishment was making it to Site 7; the second was that we arrived here in time to conduct a significant amount of science. When we left South Pole, we were already three days behind schedule. We planned for six days at Site 7, but were aware than any delays would cut into our program planned for this site. Over the next seven weeks, we saved time when possible, and gained a half-day here, and another half-day there. As we pulled into Site 7, we had saved enough time to be able to spend five full days here.
This allowed us enough time to accomplished nearly all of our goals here. The deep drilling crew recovered an 80 metre core for chemical analysis before giving the hole to Zoe for video logging, and finally to Ted and Andreas to install a thermistor string to measure the ice temperature. The deep drilling team then moved over and collected at 25m core for analysis of the physical properties (such as the grain size, density and permeability for the firn) before spending the last day taking the entire drill apart and packing it away for shipment back to the United States.
Zoe dug yet another 2m snow pit (well, 2.25m actually) and spent two days making a variety of measurements, before helping Tom collect the last of the hand-drilled firn cores. Tom and Anna also took advantage of the opportunity to complete a shallow radar survey around the drill site, to learn more about how the snow accumulation and surface topography vary locally. The radar crew also spent an afternoon backtracking about 25km to further investigate an interesting subglacial mountain. Everyone spent time packing boxes, and getting ready for the last stretch of driving down to meet the cargo ship at the ice shelf edge. Of course, the science never stops, and we will be collecting radar and GPS data as we make our way north.
The stop at Site 7 ended with the gale and technical delay we wrote about in yesterday’s blog, but today – after having driven through all of last night – we are back on schedule again. We have descended to 2400 metres above sea level, the gale has abated, and the temperature has risen to a balmy -24 C. All of the high plateau is in fact behind us, and best of all: we have mountains around us again – a feast for the eyes after more than two months of utter level whiteness!
Tom drilling a short core with the hand auger one of the balmier days at Site 7. Photo: Stein Tronstad/NPI