Abstract
Abstract. A total of 84 seismic profiles, mainly from the western and eastern deltas of Lake Issyk-Kul, were used to identify lake-level changes. Seven stratigraphic sequences were reconstructed, each containing a series of delta lobes that were formed during former lake-level stillstands or during slow lake-level increase or decrease. The lake level has experienced at least four cycles of stepwise rise and fall of 400 m or more. These fluctuations were mainly caused by past changes in the atmospheric circulation pattern. During periods of low lake levels, the Siberian High was likely to be strong, bringing dry air masses from the Mongolian steppe blocking the midlatitude Westerlies. During periods of high lake levels, the Siberian High must have been weaker or displaced, and the midlatitude Westerlies could bring moister air masses from the Mediterranean and North Atlantic regions.
Highlights
In the marine environment, global eustatic sea-level curves are traditionally used to reconstruct the amount of water stored on continents and in the oceans (e.g., Haq et al, 1987; Fleming et al, 1998; Lambeck et al, 2014; Dutton et al, 2015)
The seismic profiles of Lake Issyk-Kul are characterized by a variety of acoustic facies
Amplitudes are generally lower in the deeper sequences, which is rather the result of limited acoustic penetration than a real signal
Summary
Global eustatic sea-level curves are traditionally used to reconstruct the amount of water stored on continents and in the oceans (e.g., Haq et al, 1987; Fleming et al, 1998; Lambeck et al, 2014; Dutton et al, 2015). Sea-level curves can be used to reconstruct glacial/interglacial cycles on a global scale. Lake-level curves, in contrast, often store a more local signal that might or might not be controlled by glacial/interglacial cycles. Many lakes with large water bodies and volumes of sediment infill are fed by extensive catchments, and provide a powerful tool for understanding paleoenvironmental and paleoclimate change on local and on regional scale. During the past 600 ka, i.e., since its formation, its water
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have