The bathymetric survey (survey of the lake’s depth) appears to have been a resounding success. With Jonathan as the muscles (paddler) and Greta as the brains (running the sonar system) things went quite well surveying the outlet lakes. The outlet lakes refer to the water that is on the terminal moraine and mark the transition from Imja Lake, the large body of water, to Imja Khola, the stream/river that the lake discharges to. Satellite imagery appears to suggest that these outlet lakes have been growing over the years, so we wanted to quantify any changes over the years. It was also a nice little test run having them stay relatively close to shore to make sure they knew how to operate the system and were comfortable navigating the kayak (but shhh don’t tell them that one!). Tomorrow, they’ll move up to the big leagues and perform a bathymetric survey on all of Imja Lake and hopefully obtain some depth measurements in the deeper sections of the lake. Only kidding, both today’s results and tomorrow’s will both be equally important.
Alina and I went to work with installing a pressure transducer to measure any changes in the lake level in addition to working on the dGPS data. Here we had a bit of a hiccup once again as the elevations associated with the dGPS appear to be consistently 40 m lower than those shown by our handheld GPS. This was a little concerning and when we measured the elevation of the outlet, it was confirmed that the elevations appear to be on the low end… The good news is that relatively speaking, the dGPS appears to give us centimetric accuracy. The bad news is that it would be wonderful if that were absolute. The next couple days we’ll work on trying to figure out the reason for this underestimation as it currently is quite mind-boggling. All in all, it was a good day of work with surprisingly nice weather.