scholarly journals Kinematics of Active Deformation Across the Western Kunlun Mountain Range (Xinjiang, China) and Potential Seismic Hazards Within the Southern Tarim Basin

2017 ◽  
Vol 122 (12) ◽  
pp. 10,398-10,426 ◽  
Author(s):  
Christelle Guilbaud ◽  
Martine Simoes ◽  
Laurie Barrier ◽  
Amandine Laborde ◽  
Jérôme Van der Woerd ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Seismic Hazards ◽  
Mountain Range ◽  
Active Deformation ◽  
Kunlun Mountain ◽  
Western Kunlun

Assessing the seismic hazards associated with one of the largest active thrust sheets: the case of the slowly deforming Western Kunlun mountain range (Xinjiang, China).

2020 ◽  
Author(s):  
Martine Simoes ◽  
Christelle Guilbaud ◽  
Jerome van der Woerd ◽  
Laurie Barrier ◽  
Roxane Tissandier ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Active Faults ◽  
Seismic Hazards ◽  
Spatial Gradient ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Thrust Sheet ◽  
Fluvial Terraces ◽  
Western Kunlun ◽  
Mountain Front

<p><span lang="EN-US">The Western Kunlun Range (WKR) is a slowly converging orogen located along the northwestern edge of the Tibetan Plateau, facing the Tarim Basin. The recent Mw 6.4 2015 Pishan earthquake along the mountain front recalls that this region remains seismically active, despite little or moderate historical seismicity. Its low deformation rates can be hardly retrieved from current geodetic data, placing limited constraints on the potential interseismic loading of the region. This is particularly critical as recent structural investigations report the existence of an extremely wide (~150-180 km) frontal thrust sheet, whose dimensions would imply the possibility of major M ≥ 8 earthquakes in the case that it is locked and slips during one single seismic event.</span></p> <p><span lang="EN-US">To place further constraints on the seismic hazards of this region, we have conducted morphological and structural analyses of active faults to unravel the geomorphic record of active deformation cumulated other multiple seismic events at specific sites. To do so, field observations, seismic profiles and high-resolution Pléiades images and DEMs were combined together with the dating of fluvial terraces. We find that shortening rates have been of 0.5-2.5 mm/yr, with most probable values of ~2 mm/yr over the last ~300-500 kyr. Our detailed morphological investigations further indicate that this shortening is variably partitioned on one or several blind ramps along the mountain front, and from there is transmitted forward all the way to the deformation front, ~150-180 km further north. As such, this extremely wide single frontal thrust sheet stands most probably as the largest active thrust sheet in the world!</span></p> <p><span lang="EN-US">Finally, previously published GPS velocity fields highlight a 2-3 mm/yr gradient in horizontal velocities across the WKR and southern Tarim basin when combined and expressed in a stable Tarim reference. Such gradient, unseen from previous analyses, is consistent with our morphological results on shortening rates. Most importantly, this spatial gradient in velocities may suggest that the frontal thrust sheet is presently partly locked, questioning the possibility of mega-earthquakes in the region.</span></p>

Investigating lateral variations in the kinematics of active deformation along the Western Kunlun mountain front (Xinjiang, China): structural and morphological analysis of the Hotan anticline

2020 ◽  
Author(s):  
Christelle Guilbaud ◽  
Martine Simoes ◽  
Laurie Barrier ◽  
Jérôme Van der Woerd ◽  
Guillaume Baby ◽  
...  
Keyword(s):  
Morphological Analysis ◽  
Mountain Range ◽  
Thrust Sheet ◽  
Active Deformation ◽  
Fluvial Terraces ◽  
Structural Style ◽  
Western Kunlun ◽  
Mountain Front ◽  
Surface Geology ◽  
Lateral Variations

<p>The Western Kunlun Range is a mountain range located at the northwestern boundary of the Tibetan Plateau, facing the Tarim Basin. Our previous combined structural and morphological investigations of the mountain front, nearby the city of Pishan where a Mw 6.4 earthquake occurred in 2015, revealed the existence of a duplex uplifting Cenozoic strata, in which only the most frontal blind ramp is presently active and slips at a probable rate of 2 to 2.5 mm/yr. Located ~100 km further east along the mountain front, the Hotan anticline seems to present a different structure from surface geology, as older strata from Mesozoic and Paleozoic outcrop. Additionally, some authors proposed that the deformation would be here accommodated by a large blind basement thrust sheet, in clear contrast with the duplexes documented further west.</p><p>To further document potential lateral variations in the structural style and how they may affect the kinematics of active deformation along the mountain front of the Western Kunlun, we carry out a structural and morphological analysis of the Hotan anticline. We build structural cross-sections based on seismic reflection profiles, and calculate the incremental uplift recorded by dated fluvial terraces to quantify shortening rates over the last ~300 kyr. Our analysis reveals that a duplex structure, located below the basement thrust sheet, presently accommodates active deformation at a rate of 0.5 to 2.5 mm/yr, with a preferred rate of ~1.6 to 2.3 mm/yr. In more detail, uplifted terraces reveal that all ramps of the duplex are active in the case of the Hotan anticline, while only the most frontal ramp is documented as active in the case of the Pishan anticline further west. These results indicate that the style and rate of active shortening are rather homogeneous all along the mountain front, in contrast with the first impression provided by surface geology. Moreover, the discrepancy between surface geology and active morphology reveals progressive structural changes over geological times, from a blind basement ramp to duplexes. However, in the details, active deformation still remains segmented as its partitioning on the various ramps of the duplexes is variable along strike.</p>

Quantitative Estimates of Holocene Glacier Mass Fluctuations on the Western Tibetan Plateau

2020 ◽  
Author(s):  
Juzhi Hou
Keyword(s):  
Tibetan Plateau ◽  
Mass Gain ◽  
The Tibetan Plateau ◽  
Alpine Glacier ◽  
Kunlun Mountain ◽  
Western Kunlun ◽  
Long Time ◽  
Western Tibetan Plateau ◽  
The Difference

<p><strong><span>Knowledge of the alpine glacier mass fluctuations is a fundamental prerequisite for understanding glacier dynamics, projecting future glacier change, and assessing the availability of freshwater resources. The glaciers on the Tibetan Plateau (TP) are sources of water for most of the major Asian rivers and their fate remains unclear due to accurate estimates of glacier mass fluctuations are lacking over long time scales. Here, we used d</span><sup><span>18</span></sup><span>O record at a proglacial open lake as proxy to estimate the Holocene glacier mass fluctuations in the Western Kunlun Mountain (WKM) quantitatively and continuously. Relative to past decades, maximum WKM glacier mass loss (-28.62±25.76 Gt) occurred at 9.5-8.5 ka BP, and maximum glacier mass gain (24.53±25.02 Gt) occurred at 1.3~0.5 ka BP, the difference in WKM glacier mass between the two periods account for ~20% of the total glaciers. Long-term changes in glacier mass suggests the TP glaciers likely face severe threats at the current rates of global warming. </span></strong></p>

scholarly journals Investigating the Recent Surge in the Monomah Glacier, Central Kunlun Mountain Range with Multiple Sources of Remote Sensing Data

2020 ◽  
Vol 12 (6) ◽  
pp. 966 ◽  
Author(s):  
Lei Guo ◽  
Jia Li ◽  
Lixin Wu ◽  
Zhiwei Li ◽  
Yanyang Liu ◽  
...  
Keyword(s):  
Remote Sensing Data ◽  
Mountain Range ◽  
Multiple Sources ◽  
Landsat Images ◽  
Kunlun Mountain ◽  
Slow Expansion ◽  
Length Changes ◽  
Pressure Melting ◽  
Mass Accumulation ◽  
Alos Prism

Several glaciers in the Bukatage Massif are surge-type. However, previous studies in this region focused on glacier area and length changes, and more information is needed to support the deep analysis of glacier surge. We determined changes in glacier thickness, motion, and surface features in this region based on TanDEM-X, ALOS/PRISM, Sentinel-1A, and Landsat images. Our results indicated that the recent surge of the Monomah Glacier, the largest glacier in the Bukatage Massif, started in early 2009 and ceased in late 2016. From 2009 to 2016, its area and length respectively increased by 6.27 km2 and 1.45 km, and its ice tongue experienced three periods of changes: side broadening (2009–2010), rapid advancing (2010–2013), and slow expansion (2013–2016). During 2000–2012, its accumulation zone was thinned by 50 m, while its ice tongue was thickened by 90 m. During 2015–2017, its flow velocity reduced from 1.2 to 0.25 m/d, and the summer velocities were much higher than winter velocities. We conclude that the recent Monomah Glacier surge is thermal-controlled. The subglacial temperature rose to the pressure-melting point because of substantial mass accumulation, and then the increased basal meltwater caused the surge.

Cenozoic basin-filling evolution of the SW Tarim Basin and its implications for the uplift of western Kunlun: Insights from (seismo)stratigraphy

2021 ◽  
Vol 562 ◽  
pp. 110149
Author(s):  
Chunyang Li ◽  
Hanlin Chen ◽  
Fengqi Zhang ◽  
Xiubin Lin ◽  
Xiaogan Cheng ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Western Kunlun

The 2015Mw 6.4 Pishan Earthquake: Seismic Hazards of an Active Blind Wedge Thrust System at the Western Kunlun Range Front, Northwest Tibetan Plateau

2016 ◽  
Vol 87 (3) ◽  
pp. 601-608 ◽  
Author(s):  
Tao Li ◽  
Jie Chen ◽  
Lihua Fang ◽  
Zhuxin Chen ◽  
Jessica A. Thompson ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Seismic Hazards ◽  
Western Kunlun ◽  
Thrust System

scholarly journals Slight glacier reduction over the northwestern Tibetan Plateau despite significant recent warming

2016 ◽  
Author(s):  
Yetang Wang ◽  
Shugui Hou ◽  
Wenling An ◽  
Hongxi Pang ◽  
Yaping Liu
Keyword(s):  
Tibetan Plateau ◽  
21St Century ◽  
The Tibetan Plateau ◽  
Early 21St Century ◽  
Mountain Glaciers ◽  
Recent Warming ◽  
Kunlun Mountain ◽  
Western Kunlun ◽  
Significant Area ◽  
The Early 21St Century

Abstract. "Pamir–Karakoram–Western-Kunlun-Mountain (northwestern Tibetan Plateau) Glacier Anomaly" has been a topic of debate due to the balanced, or even slightly positive glacier mass budgets in the early 21st century. Here we focus on the evolution of glaciers on the western Kunlun Mountain and its comparison with those from other regions of the Tibetan Plateau. The possible driver for the glacier evolution is also discussed. Western Kunlun Mountain glaciers reduce in area by 0.12 % yr−1 from 1970s to 2007–2011. However, there is no significant area change after 1999. Averaged glacier thickness loss is 0.08 ± 0.09 m yr−1 from 1970s to 2000, which is in accordance with elevation change during the period 2003–2008 estimated by the ICESat laser altimetry measurements. These further confirm the anomaly of glaciers in this region. Slight glacier reduction over the northwestern Tibetan Plateau may result from more accumulation from increased precipitation in winter which to great extent protects it from mass reductions under climate warming during 1961–2000. Warming slowdown since 2000 happening at this region may further mitigate glacier mass reduction, especially for the early 21st century.

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