Ice-Gouging Topography of the Exposed Aral Sea Bed

Abstract

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.

Mapping the relief and other objects of the Aral Sea (as it dries out) using satellite images

“…On the saline soil of the seabed, show on the map the vegetation that is planted for cleaner air, which is necessary for the inhabitants of the Aral Sea region. Along with this, on the previously drained seabed, it was found that next to and close to these plantings, self-overgrowth covered another 200 thousand hectares [4]. Nature itself is trying to recover on the dried bottom.…”

“…A large soda plant was built in the Kungrad area. On the dried bottom, many drilling units operate to drill wells for natural gas production [4]. All these developments and new industrial plants must be shown with symbols on maps.…”

“…Neighboring states: in the east -Kyrgyzstan; in the northeast, north and northwest -Kazakhstan; in the southwest and south -Turkmenistan; in the south -Afghanistan and in the southeast -Tajikistan [1,2]. This work will discuss the topic of showing the relief of the dried bottom of the Aral Sea with contours, as well as soils and types of sand, and vegetation on maps [3,4]. Before the bottom was hidden by water, the bottom relief was depicted with isobaths; now it became necessary to show the bottom with horizontal lines, as well as soils, sands and vegetation that was planted on the dried bottom (Fig.…”

Ice Features Of The Northern Caspian Under Sea Level Fluctuations And Ice Coverage Variations

“…Bukharitsin (1984) showed that the sea level decrease in 1974-1980 led to the displacement of the zone most intense ridging to the deeper zone and southward from the coast. In similar conditions of sea level drop at the Aral Sea Maznev et al (2019) showed the offset of ice features and the most intensive ice gouging area away from the initial coastline. The present study shows that sea level rise by 1 m leads to changes in stamukhi locations.…”

RPFNet: Recurrent Pyramid Frequency Feature Fusion Network for Instance Segmentation in Side-Scan Sonar Images

“…A S an important acoustic sensor device for ocean exploration, side-scan sonar (SSS) is widely used in seabed topography surveying [1], shipwreck salvage [2], underwater archaeology [3], etc. For SSS image processing, many Corresponding author:wangzhen4013@163.com Zhen Wang and Shanwen Zhang are with the School of Information Engineering, Xijing University, Xi'an 710123, China (e-mail: wangzhen4013@163.com, wjdw716@163.com) Buhong Wang is with the School of Information and Navigation, Air Force Engineering University, Xian 710082, China (e-mail: wbhgroup@163.com) Chuanlei Zhang is with the School of Artificial Intelligence, Tianjin University of Science and Technology, Tianjin, China, 300457 (email:97313114@tust.edu.cn) [16].…”