TY - JOUR A1 - Scherler, Dirk A1 - Bookhagen, Bodo A1 - Wulf, Hendrik A1 - Preusser, Frank A1 - Strecker, Manfred T1 - Increased late Pleistocene erosion rates during fluvial aggradation in the Garhwal Himalaya, northern India JF - Earth & planetary science letters N2 - The response of surface processes to climatic forcing is fundamental for understanding the impacts of climate change on landscape evolution. In the Himalaya, most large rivers feature prominent fill terraces that record an imbalance between sediment supply and transport capacity, presumably due to past fluctuations in monsoon precipitation and/or effects of glaciation at high elevation. Here, we present volume estimates, chronological constraints, and Be-10-derived paleo-erosion rates from a prominent valley fill in the Yamuna catchment, Garhwal Himalaya, to elucidate the coupled response of rivers and hillslopes to Pleistocene climate change. Although precise age control is complicated due to methodological problems, the new data support formation of the valley fill during the late Pleistocene and its incision during the Holocene. We interpret this timing to indicate that changes in discharge and river-transport capacity were major controls. Compared to the present day, late Pleistocene hillslope erosion rates were higher by a factor of similar to 2-4, but appear to have decreased during valley aggradation. The higher late Pleistocene erosion rates are largely unrelated to glacial erosion and could be explained by enhanced sediment production on steep hillslopes due to increased periglacial activity that declined as temperatures increased. Alternatively, erosion rates that decrease during valley aggradation are also consistent with reduced landsliding from threshold hillslopes as a result of rising base levels. In that case, the similarity of paleo-erosion rates near the end of the aggradation period with modern erosion rates might imply that channels and hillslopes are not yet fully coupled everywhere and that present-day hillslope erosion rates may underrepresent long-term incision rates. (C) 2015 Elsevier B.V. All rights reserved. KW - paleo-erosion rates KW - climate change KW - river terraces KW - landscape evolution KW - hillslopes KW - Himalaya Y1 - 2015 U6 - https://doi.org/10.1016/j.epsl.2015.06.034 SN - 0012-821X SN - 1385-013X VL - 428 SP - 255 EP - 266 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rosenwinkel, Swenja A1 - Landgraf, Angela A1 - Schwanghart, Wolfgang A1 - Volkmer, Friedrich A1 - Dzhumabaeva, Atyrgul A1 - Merchel, Silke A1 - Rugel, Georg A1 - Preusser, Frank A1 - Korup, Oliver T1 - Late Pleistocene outburst floods from Issyk Kul, Kyrgyzstan? JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group KW - outburst flood KW - lake-level changes KW - Issyk Kul KW - Kyrgyzstan KW - cosmogenic nuclides Y1 - 2017 U6 - https://doi.org/10.1002/esp.4109 SN - 0197-9337 SN - 1096-9837 VL - 42 SP - 1535 EP - 1548 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Patyniak, Magda A1 - Landgraf, Angela A1 - Dzhumabaeva, Atyrgul A1 - Abdrakhmatov, Kanatbek E. A1 - Rosenwinkel, Swenja A1 - Korup, Oliver A1 - Preusser, Frank A1 - Fohlmeister, Jens Bernd A1 - Arrowsmith, J. Ramon A1 - Strecker, Manfred T1 - Paleoseismic Record of Three Holocene Earthquakes Rupturing the Issyk-Ata Fault near Bishkek, North Kyrgyzstan JF - Bulletin of the Seismological Society of America N2 - The northern edge of the western central Tien Shan range is bounded by the Issyk-Ata fault situated south of Bishkek, the capital of Kyrgyzstan. Contraction in this thick-skinned orogen occurs with low-strain accumulation and long earthquake recurrence intervals. In the nineteenth to twentieth centuries, a sequence of large earthquakes with magnitudes between 6.9 and 8 affected the northern Tien Shan but left nearly the entire extent of the Issyk-Ata fault unruptured. Here, the only known historic earthquake ruptured in A.D. 1885 (M6.9) along the western end of the Issyk-Ata fault. Because earthquakes in low-strain regions often tend to cluster in time and may promote failure along nearby structures, the earthquake history of the northern Tien Shan represents an exceptional structural setting for studying fault behavior affected by an intraplate earthquake sequence. We present a paleoseismological study from one site (Belek) along the Issyk-Ata fault located east of the A.D. 1885 epicentral area. Our analysis combines a range of tools, including photogrammetry, differential Global Positioning System, 3D visualization, and age modeling with different dating methods (infrared stimulated luminescence, radiocarbon, U-series) to improve the reliability of an event chronology for the trench stratigraphy and fault geometry. We were able to distinguish three different surfacerupturing paleoearthquakes; these affected the area before 10.5 +/- 1.1 cal ka B.P., at similar to 5.6 +/- 1.0 cal ka B.P., and at similar to 630 +/- 100 cal B.P., respectively. Associated paleomagnitudes for the last two earthquakes range between M6.7 and 7.4, with a cumulative slip rate of 0.7 +/- 0.32 mm/yr. We did not find evidence for the A.D. 1885 event at Belek. Our study yielded two main overall results: first, it extends the regional historic and paleoseismic record; second, the documented rupture events along the Issyk-Ata fault suggest that this fault was not affected in its entirety; instead, these events indicate segmented rupture behavior. Y1 - 2017 U6 - https://doi.org/10.1785/0120170083 SN - 0037-1106 SN - 1943-3573 VL - 107 SP - 2721 EP - 2737 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Margold, Martin A1 - Jansen, John D. A1 - Gurinov, Artem L. A1 - Codilean, Alexandru T. A1 - Fink, David A1 - Preusser, Frank A1 - Reznichenko, Natalya V. A1 - Mifsud, Charles T1 - Extensive glaciation in Transbaikalia, Siberia, at the Last Glacial Maximum JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - Successively smaller glacial extents have been proposed for continental Eurasia during the stadials of the last glacial period leading up to the Last Glacial Maximum (LGM). At the same time the large mountainous region east of Lake Baikal, Transbaikalia, has remained unexplored in terms of glacial chronology despite clear geomorphological evidence of substantial past glaciations. We have applied cosmogenic Be-10 exposure dating and optically stimulated luminescence to establish the first quantitative glacial chronology for this region. Based on eighteen exposure ages from five moraine complexes, we propose that large mountain ice fields existed in the Kodar and Udokan mountains during Oxygen Isotope Stage 2, commensurate with the global LGM. These ice fields fed valley glaciers (>100 km in length) reaching down to the Chara Depression between the Kodar and Udokan mountains and to the valley of the Vitim River northwest of the Kodar Mountains. Two of the investigated moraines date to the Late Glacial, but indications of incomplete exposure among some of the sampled boulders obscure the specific details of the post-LGM glacial history. In addition to the LGM ice fields in the highest mountains of Transbaikalia, we report geomorphological evidence of a much more extensive, ice-cap type glaciation at a time that is yet to be firmly resolved. (C) 2015 Elsevier Ltd. All rights reserved. KW - Glaciation KW - Transbaikalia KW - Last Glacial Maximum KW - Cosmogenic Be-10 exposure dating KW - Optically stimulated luminescence Y1 - 2016 U6 - https://doi.org/10.1016/j.quascirev.2015.11.018 SN - 0277-3791 VL - 132 SP - 161 EP - 174 PB - Elsevier CY - Oxford ER -