Lake E News of the Day April 5
Privet! The downhole logging started early Saturday morning was completed today by about 1 PM after a nearly 30 hr marathon effort by ICDP OSG representatives Martin Topfler and Jochem Kuck, assisted by Catalina Gebhardt. Molodezts! Logging was done methodically in 50-meter sections starting with the lowest materials from -100 to -150 meters. The same measurements were then repeated over the -50 to -100 m depth section and the 0 to -50 m depth section. Just some quick highlights -- the acoustic camera showed that the borehole is ideally round along its length without any cavitation into the sand and gravel. Some small faults were detected. The magnetic susceptibility measurements are of good quality to about -50 m depth but below that they are compromised, shall we say, by interference caused by the proximity of one of the lost drill pipes in either core site 1a or 1b. The temperature probe recorded temperatures of 4 deg C at the lake floor, as expected, with the warmest temperatures of about +9 deg. C (48 deg. F) at -150 m in the bottom of the borehole. We believe this suggests a normal geothermal gradient into the talik and beyond beneath the lake.
Convoy update: Today we learned that the one truck broken down 80 km from camp has been repaired. The expectation now is that the entire convoy (with all of our remaining casing, mud, and the Kawasaki mule) will reach the camp sometime tomorrow with the assistance of one of the bulldozers to help pull the trucks over the mountains and into the low pass leading to the crater and the camp.
Upon completion of the down hole logging, the dayshift resumed rotary drilling with the Alien sometime mid-afternoon. The going was tough again, however, with poor recovery of 30 to 60%, but mostly on the low side. A full thermo-box of cores was taken at depths from 149 to 162 m with lithologies dominated by very stiff clay diamicts.
Volker checked free board around the drill pad and measured values around 10 cm with an ice thickness of 2.1m; in one place the ice was up to 2.21. He now has 3 sets of snow fences up around the rig that are successfully catching wind drifted snow.
Today the weather was clear for the most part but the wind has picked up from the north. Now all of the national flags on the pole outside the science lab are straight out. We continue to have lows to -30 C and day temps in the range of -20C or so.
Cheers from the Lake....Julie BG
