Monitoring surging glaciers of the Pamirs, central Asia, from space

Abstract

The evolution of surging glaciers of the Pamirs, central Asia, has been studied using repeat remote-sensing surveys in the Institute of Geography, Russian Academy of Sciences, since the early 1970s. We use images obtained from national Resurs-F satellites (1972–91), as well as Landsat 7 and Terra (1999–2006), to provide a basis for monitoring of surging glaciers, aimed at developing their inventory, studying the causes and mechanisms of surges and examining the timing and extent of glacial catastrophes. The inventory from the early 1990s allows identification of 215 glaciers with a dynamically unstable regime. We discovered 51 surging glaciers. Up until 2006, 10 more surges had occurred. We use stereoscopic deciphering and photogrammetric processing of consecutive satellite images to study the morphology and ice-velocity changes of several compound surging glaciers. We analyze the results of monitoring of Bivachny and Oktyabr’sky glaciers from 1972 to 1991 and Sugran glacier from 1972 to 2006. Two surges of Sugran glacier occurred during this time: an internal surge in 1976–80, and a surge with glacier tongue advance as far as 4.5 km in 2000–05. The role of damming in compound glacier systems is examined. Satellite-based monitoring is now the only method for obtaining initial information about the state and fluctuations of such glaciers.

Glacier characteristics and changes in the Sary-Jaz River Basin (Central Tien Shan, Kyrgyzstan) – 1990–2010

“…This may be a result of the location, which is closer to Issyk-Kul Basin, where moist air masses originating from the large lake penetrate through the Terskey Alatau Range (Dikikh et al 1991). The advancing and surging of glaciers has been described for the Karakorum (Copland et al 2011) and the Pamir (Kotlyakov et al 2008), as well as some Tien Shan ranges (Dolgushin and Osipova 1975, Narama et al 2010, Pieczonka et al 2013; and is now reported for the first time for the 'SJRB'. Surprisingly, the largest glacier, No.…”

A Glacier Surge of Bivachny Glacier, Pamir Mountains, Observed by a Time Series of High-Resolution Digital Elevation Models and Glacier Velocities

“…From comparison of the sparsely available satellite imagery from 1991 and 2003, Kotlyakov et al [5] suspected that a surge happened in the early 1990s. Our analysis of Landsat images from this period that have become available since then reveals that this surge took place in 1996/1997.…”

“…Bivachny Glacier is known to have surged thrice in the 20th century, in 1958,[1976][1977][1978] and "soon after" 1991 [5]. The most evident sign of a surge at Bivachny is the displacement of the looped moraine of the MGU Glacier tributary (Figure 1; see Figure 2 for the most recent surge).…”

“…Based on optical space images, Kotlyakov et al [5] identified 55 glaciers that surged between 1973 and 2006, and 215 glaciers that showed signs of recent instability. The best studied surging glacier in the region so far is the Medvezhiy Glacier, which was intensively studied regarding both velocity and elevation changes during a complete surge cycle from 1973 to 1989 [9] with possible hydrological forcing of the surges discussed in [27].…”

“…Surge-type glaciers are concentrated in some glaciated regions of the world, like the Alaskan-Canadian Arctic (e.g., [1,2]), Svalbard [3] and Pamir-Karakoram [4,5], whereas they are currently absent from other regions like Antarctica or the Alps [6]. There exist some well-studied glacier surges, for example at Variegated Glacier, Alaska [7,8]; Medvezhiy Glacier, Pamir [9] and in Svalbard (e.g., [10,11]).…”