Be exposure dating of river terraces at the southern mountain front of the Dzungarian Alatau (SE Kazakhstan) reveals rate of thrust faulting over the past ~ 400 ka     

Anja Cording  Ralf Hetzel  Martin Kober  Jonas Kley 《Quaternary Research》2014

The mountain belts of the Dzungarian Alatau (SE Kazakhstan) and the Tien Shan are part of the actively deforming India–Asia collision zone but how the strain is partitioned on individual faults remains poorly known. Here we use terrace mapping, topographic profiling, and ¹⁰Be exposure dating to constrain the slip rate of the 160-km-long Usek thrust fault, which defines the southern front of the Dzungarian Alatau. In the eastern part of the fault, where the Usek River has formed five terraces (T₁–T₅), the Usek thrust fault has vertically displaced terrace T₄ by 132 ± 10 m. At two sites on T₄, exposure dating of boulders, amalgamated quartz pebbles, and sand from a depth profile yielded ¹⁰Be ages of 366 ± 60 ka and 360 ^+ 77/_− 48 ka (both calculated for an erosion rate of 0.5 mm/ka). Combined with the vertical offset and a 45–70° dip of the Usek fault, these age constraints result in vertical and horizontal slip rates of ~ 0.4 and ~ 0.25 mm/a, respectively. These rates are below the current resolution of GPS measurements and highlight the importance of determining slip rates for individual faults by dating deformed landforms to resolve the pattern of strain distribution across intracontinental mountain belts.  相似文献   

Temperature assimilation into a coastal ocean-biogeochemical model: assessment of weakly and strongly coupled data assimilation     

Goodliff  Michael  Bruening  Thorger  Schwichtenberg  Fabian  Li  Xin  Lindenthal  Anja  Lorkowski  Ina  Nerger  Lars 《Ocean Dynamics》2019,69(10):1217-1237

Ocean Dynamics - Satellite data of both physical properties as well as ocean colour can be assimilated into coupled ocean-biogeochemical models with the aim to improve the model state. The physical...  相似文献   

Trends and variation in concentration of dissolved metals (Cd, Cu, Pb, and Zn) in the North Sea (1980-1989)     

Scholten  M. C. Th.; Kramer  K. J. M.; Laane  R. W. P. M. 《ICES Journal of Marine Science》1998,55(5):825-834

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Sediment accumulation rates in subpolar fjords – Impact of post-Little Ice Age glaciers retreat,Billefjorden, Svalbard     

Witold Szczuciński  Marek Zajączkowski  Jan Scholten 《Estuarine, Coastal and Shelf Science》2009

The Little Ice Age (∼1600–1900 AD) and 20th century sediment accumulation rates in Billefjorden, a subpolar fjord on Svalbard, were reconstructed by applying ²¹⁰Pb, ¹³⁷Cs and AMS ¹⁴C datings. The modern sediment accumulation rate decreases from more than 0.39 cm y⁻¹ at the fjord head to 0.08 cm y⁻¹ close to the fjord mouth. However, during the Little Ice Age the sediments accumulated at a much lower rate of 0.02 cm y⁻¹ in the central fjord basin. This difference is most likely related to the rapid retreat of glaciers during the 20th century, when most of them withdrew up to 2 km. The post-Little Ice Age increases in temperature and a negative glacier mass balance resulted in a larger meltwater discharge transferring substantial amounts of sediments released from the glaciers, as well as those eroded from previously stored unconsolidated glacial sediments. A comparison of data from the subpolar fjords of Svalbard suggests that the increase in the sediment accumulation rate is a common trend, and further increases might be expected if climate warming continues. The properties of the fjord sediments (grain size, IRD, coarse-fraction composition, clay mineralogy) from the Little Ice Age and the 20th century showed no distinct differences. The change in the accumulation rate may be the most evident sedimentary record of this climatic change.  相似文献