Subsurface deposits detection and shoreline feature interpretation of a vanished Lop Nur lake using multi-source SAR data

Abstract

Lop Nur, located at the east end of Tarim Basin, northwest China, is a huge vanished lake dried up before the 1970s. With the advantage of penetration capability and sensitivity to moist saline materials, synthetic aperture radar revealed the subsurface lacustrine deposits, delineated the partially buried shorelines and depicted a complete picture of Lop Nur Lake that leads to three important scientific findings in this study. Based on scattering mechanism interpretation of polarimetric and multiple frequency SAR data, field investigation and sample analysis, it is found that the total area of the vanished Lop Nur Lake is more than 10,300 km 2 , much larger than earlier reports. The relatively younger West Lake is superposed on the top of the lacustrine deposits of East Lake which makes the well known “Ear” feature of Lop Nur, so the west part of the shoreline is buried and not visible on optical remote sensing images. Therefore the Lop Nur Lake actually has nearly circular, closed shorelines. The drying-up process of East Lop Nur Lake went through six phases according to the shorelines interpreted from multiple SAR data. The shrinking phases of Lop Nur Lake indicate the climate changes between dry and wet environment conditions.