Tipping points in lake systems of the arid zone of Central Asia – Q-TiP

 

Influence of tipping points on landscape systems

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Veit Christian Nottebaum

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+49 241 80 96049

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  Western end of Orog Nuur, sand sheets in the east, and lake sediments V. Nottebaum Upper left: the western end of Orog Nuur, taken from tectonically uplifted alluvial fan surfaces; lower left: partly stabilized sand sheets east of Orog Nuur; right: lake sediments about 60m above the present lake level.

The Q-TiP project is funded by the German Minsitry of Education and Research, BMBF, for the period of October, 2016 to September, 2019. The appearance and desiccation of large central Asian lake systems is investigated within three sub-projects. In South Mongolia’s Gobi Desert, the sub-project “Influence of Tipping Points on the Landscape Systems” driven by our group and the working group for Neotectonics and Natural Hazards at the RWTH Aachen University, investigates the catchment of the Orog Nuur, which exhibits traces of strong neotectonic activity. In 1957, the region experienced a magnitude 8 earthquake with its epicenter only a few tens of km west of Orog Nuur. Sediment cascades and their archives are observed regarding the influence of tipping points. These thresholds may be climatically or tectonically controlled and their crossing may significantly influence the hydrological system of the lake and the landscape. The landscape around the lake is in a special focus: The interaction of fluvial, lacustrine and aeolian archives is investigated by sedimentological and geochronological means, thus delivering information about the landscape evolution during the last glacial cycle.

  Beach ridges at Orog Nuur, expedition camp, and aeolian cover layer V. Nottebaum Upper left: beach ridge 23m above the lake level on the northern lake shore; lower left: expedition camp on the 16m beach ridge on the southern shore, with the Ikh Bogd mountain range in the background; right: sandy-silty aeolian cover layer.

Reconstruction of the paleoenvironment

The work reconstructs the landscape history from the last Glacial to the late Holocene, while also tectonic influence is considered together with the colleagues from the group for neotectonics. From the local example at Orog Nuur general conclusions about the influence of tipping points on geomorphological processes in central Asian lake systems during the last glacial cycle will be derived.

Field work

In summer 2017, we went for four weeks on a field trip to Orog Nuur. At over 60 locations, surface and sediment sections were investigated and sampled. More than 30 OSL samples were taken for geochronological data of sediment deposition. In the main focus were beach ridges and associated fluvial, aeolian and lacustrine sediments.

 
Duration 10/2016 - 09/2019
Funding BMBF
Project partners Jorien van der Wal Neotectonics and Natural Hazards, RWTH Aachen
Prof. Dr. Klaus Reicherter Neotectonics and Natural Hazards, RWTH Aachen