Surges of the Pamir Glaciers in the First 20 Years of the 21st Century
- PDF / 811,754 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 14 Downloads / 216 Views
RAPHY
Surges of the Pamir Glaciers in the First 20 Years of the 21st Century Academician V. M. Kotlyakova,*, L. V. Desinova, S. L. Desinova, and V. A. Rudakova Received August 27, 2020; revised August 31, 2020; accepted September 4, 2020
Abstract—The activation of surging glaciers in the Pamirs over the past 20 years has been studied. Glacier surges occurred in the basins of the Surkhob, Muksu, Sauksai, Seldara (including the Fedchenko Glacier system), Obihingou, and Vanch rivers. Pulsational processes were detected on 48 glaciers against the background of a general glacier retreat under the influence of global warming. Features of glacier activation, development of pulsational processes, and their completion are shown. There was no clear association of glacier surges with seismic events, with the exception of three cases when earthquakes caused rock collapses that could have caused glaciers to activate. Keywords: surging glacier, front of growing activity, active phase, river basin, surge, glacier tongue, monitoring, space image DOI: 10.1134/S1028334X20110082
The surging glaciers differ from the ordinary ones in that the slow motion of ice in the surging glaciers periodically changes to accelerated motion with time intervals close in duration (various for different glaciers). Glacier surges are not associated with earthquakes and climatic fluctuations. They are caused by dynamic processes in a glacier itself. Most of the glacier surges occur outside populated areas, deep in mountain valleys and do not pose risks to the local populations and infrastructure. However, in some cases, when lateral valleys and gorges are dammed, lakes may arise and break through an ice dam, thus creating catastrophic situations. Forty years ago, the first surging glaciers were revealed and studied precisely in the Pamirs. The basic patterns of their evolution were established, and their indicational characteristics were systematized [1]. By the beginning of the third decade of the 21st century, the time had come to utilize the data on the Pamir glaciers, which are unstable in terms of dynamic. About sixty indications of the pulsational changes of glaciers are known. Many of them may be indicated only by a field survey with the use of unmanned aerial vehicles or visual observations from a helicopter. However, some indications of glacier surges are manifested very clearly; they can be seen on space images with high and medium resolution. It must be admitted a Institute
of Geography, Russian Academy of Sciences, Moscow, 119017 Russia *e-mail: [email protected]
that this job requires highly professional skills and the experience of ground studies. The ground methods of data collection on the surging glaciers are restricted due to hard-to-reach mountains. In recent years, the situation became more complex as the stationary stations for observation and measurement in the Pamir high-mountain region were completely eliminated. In the 1970s and 1980s, the Pamirs served as a test site, where the scientific staff of the Institute of Geography,
Data Loading...
