Seismic investigation of Lake Issyk-Kul sediments - paleoclimatic and tectonic evolution of the lake and its basin

• Applicant: Privatdozentin Dr. Andrea Catalina Gebhardt
• Subject Area: Palaeontology
• Term: from 2011 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 194345370

• Final Report Year: 2015

Final Report Abstract

The goal of the project ISSYKKUL-SEIS was to establish a paleoclimate record of the Lake Issyk-Kul region using all existing sparker seismic profiles. A thorough interpretation of the data set was carried out and revealed large stacked‐delta complexes on both the eastern and western end of the lake (Lake dimensions: Length 180 km, 60 km; stacked-delta complex width up to 60 km). The stacked-delta complexes contain at least 7 stratigraphic sequences; the seismic signal did not penetrate to the acoustic bedrock. Each sequence contains a succession of sediments that were deposited either during rising or falling sea level, marked by a series of distinct deltas. A lake‐level curve could be established using the depth of the delta edges. This curve shows 4 phases of lake‐level increase interrupted by a total of 4 phases of lake‐level decreases. This record, however, does not include terraces that are currently subaerially exposed, because they are not mapped in the seismic images. One of the subaerially exposed lake terraces at ca. 20 to 40 m above the current lake level was dated to 26 to 10.5 ka by Bowman et al. (2004), suggesting wetter conditions during MIS 2 than today.

Publications

• 2011. Seismic reflection data from Lake Issyk-Kul, Kyrgyzstan. Proceedings IODP/ICDP Kolloquium Münster, 14. - 16.03.2011, pp. 66-67.
  Gebhardt, A.C., De Batist, M., Naudts, L., De Mol, L.
  
• 2012. Lake Issyk-Kul, Kyrgyzstan: Seismic investigation of the lacustrine sediments. Proceedings ICDP/IODP-Kolloquium, 7-­9 March, 2012. Kiel, pp. 54.
  Gebhardt,A.C., De Batist, M., Naudts, L., De Mol, L.
  
• 2012. Seismic investigation of Lake Issyk-Kul, Kyrgyzstan. Geophysical Research Abstracts, Vol. 14. 2012, 9th EGU General Assembly, 22-27 April, Vienna.
  Gebhardt, A.C., Naudts, L., De Mol, L., De Batist, M.
  
• 2013. Seismic Data Reveal Lake--‐Level Changes in Lake Issyk-Kul, Kyrgyzstan. American Geophysical Union, Fall Meeting 2013, 9-13 December, San Francisco, abstract #PP53A-1989.
  Gebhardt, A. C., Spiess, V., Keil, H., Sauermilch, I., Oberhänsli, H., Abdrakhmatov, K., De Batist, M., Naudts, L., De Mol, L.
  
• 2014. An Airgun Seismic Survey for Preparation/Support of ICDP Drilling at Lake Issyk-Kul, Kyrgyztan - Opportunities for Tectonic and Sedimentary Process Studies. Proceedings ICDP/IODP- Kolloquium, 17-19 March, 2014, Erlangen, pp. 128-129.
  Spiess, V., Keil, H., Sauermilch, I., Said, A., Abdrakhmatov, K., Gebhardt, A.C., Oberhänsli, H.