Ice-Gouging Topography of the Exposed Aral Sea Bed

Remote Sensing

Stanislav Ogorodov¹  Aleksey Vergun¹  Vasiliy Arkhipov¹  Alisa Baranskaya¹  Stepan Maznev¹  Peter Bukharitsin² 

[1] Laboratory of Geoecology of the North, Faculty of Geography, Lomonosov Moscow State University, GSP-1 1, Leninskie Gory, Moscow 119991, Russia;Water Problems Institute, Russian Academy of Sciences, Tatischeva street 16, Astrakhan 414056, Russia;

关键词: Aral Sea;    ice gouging;    bottom topography;    ice scours;    remote sensing;   

DOI  :  10.3390/rs11020113

来源: DOAJ

【 摘 要 】

Ice gouging, or scouring, i.e., ice impact on the seabed, is a well-studied phenomenon in high-latitude seas. In the mid-latitudes, it remains one of the major geomorphic processes in freezing seas and large lakes. Research efforts concerning its patterns, drivers and intensity are scarce, and include aerial and geophysical studies of ice scours in the Northern Caspian Sea. This study aims to explain the origin of the recently discovered linear landforms on the exposed former Aral Sea bottom using remotely sensed data. We suggest that they are relict ice gouges, analogous to the modern ice scours of the Northern Caspian, Kara and other seas and lakes, previously studied by side scan sonar (SSS) surveys. Their average dimensions, from 3 to 90 m in width and from hundreds to thousands of meters in length, and spatial distribution were derived from satellite imagery interpretation and structure from motion-processing of UAV (unmanned aerial vehicle) images. Ice scouring features are virtually omnipresent at certain seabed sections, evidencing high ice gouging intensity in mid-latitude climates. Their greatest density is observed in the central part of the former East Aral Sea. The majority of contemporary ice gouges appeared during the rapid Aral Sea level fall between 1980 and the mid-1990s. Since then, the lake has almost completely drained, providing a unique opportunity for direct studies of exposed ice gouges using both in situ and remote-sensing techniques. These data could add to our current understanding of the scales and drivers of ice impact on the bottom of shallow seas and lakes.

【 授权许可】

Unknown