B01 and B02 Ceased Transmissions August 30, 2011 Over the last two weeks, B01 and B02 have apparently stopped transmitting data. B01's last data package uploaded to our server came in August 21; B02's last was August 27. It seems likely now that no more transmissions will follow from either site. In the case of B01, the reason that data transmissions have stopped is likely that the instrumentation fell into the crevasse so near it. This is an unavoidable hazard of glacier research! In the case of B02, it isn't yet clear what went wrong. The problem isn't related to battery voltage. It may be that B02 has fallen into a newly-opened crevasse.

Latest from Bering Glacier Field Trip July 31, 2011 MTRI scientists and engineers recently returned from the July excursion to the Bering Glacier. A major objective of the trip was to service the Glacier Ablation Sensor System (GASS), which monitors melt on the Bering at 6 different sites (B01, B02, B03, B04, B06, and T01). After several weeks of melt, these instruments were hanging 4 to 5 meters in the air! At that height, ablation measurements are less accurate. Our field team lowered the instruments on the poles after measuring the height of the instruments. Check out recent photos B01 (near the terminus) and B02 (up glacier, near the Grindle Hills). Sites B06, B04, and T01, which do not transmit data in real time, were successfully serviced and their data downloaded. Unfortunately, site B03 could not be serviced nor its data recovered because it was in the middle of a meltwater pond (photo). BLM employees might have been able to recover this instrument after we left, provided the pond drained. Site B01 was able to be serviced but due to its proximity to a crevasse it will likely not be accessible again; it is likely not recoverable. Fortunately, B01 will continue to transmit its data in real-time until something happens to prevent it from doing so! Site B02 was outfitted with a horizontal-axis wind power generator which we hope will keep it running through (most of) the winter, when solar power is not as reliable. After some updates to the website, real-time data from B01 and B02, still being transmitted, are available once again. Look for data from the non-transmitting sites B04, B06 and T01 to be available for download soon.

MTRI Scientists Revisit the Bering Glacier July 22, 2011 MTRI scientists are currently at the Bering Glacier making annual observations. Most importantly, the GASS units are being serviced. Throughout the summer, the top surface of the glacier recedes from the GASS sensors as it melts. By mid-July, the GASS units are so far from the surface that ablation measurements are less accurate. Consequently, you will see some errors in the real-time presentation of data from B01 and B02. Please excuse the mess! Updates are planned in the near future. When we return from the field, website content will be updated to accomodate the changes. Also, the data thus far from the non-reporting stations B03, B04, B06, and T01 will also be made available (these stations do not report in real-time).

The Bering Glacier is Surging June 13, 2011 The following was prepared by Dr. Edward Josberger, Glacier-Climate Scientist (Retired) and Senior Scientist, MTRI. What is a surging glacier? Surging glaciers are glaciers that exhibit surge behavior; that is, long periods of typical, low glacier flow speeds are replaced by short periods of rapid flow. The variable interval between surges can be ten to one hundred years and ice speeds can be 10 to 100 times normal. A surge can, rapidly transport large amounts of ice out of the accumulation zone into the ablation zone of the glacier, and the terminus of a surging glacier can advance many kilometers over the course of the surge. For Bering Glacier, surges occur every 10 to 20 years, greatly fracturing the glacier surface. Ice speeds can reach 100 m/day at the terminus but are about 10 m/day up glacier and Vitus Lake, a large pro-glacial lake at the terminus, can be virtually overrun. What causes a surge? The causes of surging behavior are poorly known. Studies indicate they are related to the supply of water to the glacier bed, “lubricating” the glacier bed, the drainage system at the bed and the accumulation of mass by the glacier. For Bering Glacier, the surge of 1995-96 ended with a large outburst flood, which indicates the importance of sub-glacial hydrologic processes for controlling surges. What are the impacts of surges? Glacier surges play an important role in the long-term mass balance of a glacier by transporting large amounts of ice down glacier into the ablation zone. The advancing terminus can temporarily dam tributary streams and overrun proglacial features, including lakes, as is the case with Bering Glacier and Vitus Lake. Bering Glacier is also a tidewater glacier, calving icebergs into Vitus Lake, the combination of surging and calving has a great impact on the mass balance of the glacier. Any relationship between climate change and surges? While the occurrence of individual surges is not directly related to climate change, climate change may alter the frequency and magnitude of surging or even cause glaciers to cease being of the surge type.