October 27, 2011
Milam Glacier Retreat, India
Posted by Mauri Pelto
Milam Glacier flows south from the summit of Trisul in the Indian Himalaya. The glacier is fed by a number of tributaries flowing off the north ridge of Nanda Devi as well. A recent paper by Raj (2011) documents the retreat of this glacier from 1954-2006. In the October 16, 2011 satellite image below, the snowline is at 5100 meters (black arrows) and the terminus at 3600 meters (red arrow). The accumulation zone stretches from the icefall regions at 5000-5200 meters to near the summit of Trisul at 7000 meters. From 1954-1976 Milam Glacier retreated at 20 Meters/year, 440 m. From 1976 to 1990 retreat was still 20 meters/year, 290 m. From 1990-2006 the glacier retreated 40 meters/year, 600 meters. The image below is from the Raj (2011) paper. Raj et al (2014) note that the glacier has retreated 480 m from 2004-2011 an acceleration. They further note an increase in the number of ponds and their size on the glacier, with the growth of 47 notable ponds on the glacier surface (Note their Figure 3, below). The Milam Glacier feeds the Gori Ganga River where a 370 MW hydropower system is anticipated to be built, the system will be a run of the river hydro project. A closeup view from Google Earth imagery of the terminus indicates its stagnant nature and the location of the glacier outlet stream emerging from the under the glacier is a good marker of the terminus, note arrow in top image below. A comparison of 2004 (middle) and 2009 (bottom) indicate the stagnant debris covered nature of the glacier terminus area. A new lake has developed upglacier of the terminus at Point A after 2004. The lake beyond the terminus at Point C has expanded. The terminus where the stream issues from under the glacier is at Point B.
Fuigure 3 from the Raj et al (2014) in Journal of Geological Society of India. The glacier is fed by a number of tributaries that now barely reach and contribute little in the way of volume to the Milam Glacier. These are labelled in the base map from Raj (2011). A closeup example is the Pachmi Drachnu Glacier. The red arrow points out the lateral moraine that now is 100 meters above the current Milam and Pachmi Drachnu Glacier surface. The blue arrow indicates the meager ice supply reaching the Milam Glacier . The Milam Glacier is a summer accumulation type glacier receiving the bulk of its melt and accumulation during the summer monsoon season. This type of glacier is not sensitive to black carbon ablation enhancement as the lower section is debris covered and the upper section covered by frequent new summer snowfall. The retreat of this glacier is similar to that of neighboring glaciers such as the Parbati Glacier, Gangotri Glacier and Satopanth Glacier
As a college student and wanna-be mountaineer my team-mates and I had first hand experience of glacial retreat (now attributed to climate change) in 1983. We were on a small expedition to climb Ikualari peak, just north of the Ikualari glacier that is a tributary of the Milam. We had “beta” from Harsh Kapadia from his expedition some 20 years previous. Based on his description, we were expecting the terminus to be close to Milam village and a snow covered glacier with filled, invisible crevasses, and a snow plod till the confluence of the Ikualari glacier with the Milam. Instead, we found the terminus had retreated significantly from where we’d expected it to be, there was no snow on the glacier, a deep gap between the eastern hillside and the surface of the glacier which made it difficult to get on to the surface of the glacier until just before the Bullantari glacier. Once on the Milam, we encountered a debris laden surface, no snow, lots of surface streams and lakes and below the debris, what looked to us like black ice. We made attempts over the next few days to penetrate to the upper part of the glacier, above the icefall, but were blocked by massive open crevasses and seracs in an impenetrable maze. One of us attempted to climb up the Bullantari (?) and see if we could descend onto the Ikualari Glacier from the intervening shoulder. On our last day we hewed close to the eastern edge as far as we could (we had no ladders). I was attempting to cross a crevasse (wider than I could have long-jumped at sea level with spikes on a track!) on what looked like a narrow but solid crossing when a huge (double the diameter of a human head) boulder rolled off the cliff above, hit the opposite side of the crevasse, shook the crossing I saw on so ice fell off the top right where I was planning my next step, fell into the crevasse and crashed its way down. I turned back when my teammates pointed out that err, it was no longer a solid crossing, more of an arch that remained.
We never got more than a glance at Ikualari Peak, our objective.