Evidence for Holocene Activity on the Jiali Fault, an Active Block Boundary in the Southeastern Tibetan Plateau

2020 ◽  
Vol 91 (3) ◽  
pp. 1776-1780
Author(s):  
Hu Wang ◽  
Kaijin Li ◽  
Lichun Chen ◽  
Xingqiang Chen ◽  
An Li
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Southeastern Part ◽  
Block Boundary ◽  
The Holocene ◽  
Hazard Assessments ◽  
Holocene Activity ◽  
Large Earthquakes ◽  
Active Block

Abstract Most active block boundary faults within the Tibetan plateau have been thought of as Holocene active, and are able to produce large earthquakes. However, it is unknown whether the Jiali fault (JLF) has been seismically active in the Holocene, which currently hampers efforts to undertake meaningful seismic hazard assessments near the southeastern part of the Tibetan plateau. In this study, it is shown that the JLF has indeed ruptured during the Holocene, as evidenced from geological, paleoseismic, and radiocarbon dating investigations. Specifically, at least two surface-rupturing paleoseismic events were revealed with ages between 2160±30  yr B.P. and 2680±30  yr B.P., and prior to 2730±30  yr B.P., respectively. Combined with previous studies on the JLF, we suggest that the fault (1) can be considered an active block boundary fault and (2) accommodates crustal deformation related to the uplift of the Tibetan plateau since the late Cenozoic.

scholarly journals Late Cenozoic Denudation and Topographic Evolution History of the Lhasa River Drainage in Southern Tibetan Plateau: Insights From Inverse Thermal History Modeling

2021 ◽  
Vol 9 ◽  
Author(s):  
Dongxu Cai ◽  
Xianyan Wang ◽  
Guangwei Li ◽  
Wenbin Zhu ◽  
Huayu Lu
Keyword(s):  
Tibetan Plateau ◽  
Surface Erosion ◽  
The Tibetan Plateau ◽  
Monsoon Precipitation ◽  
Late Cenozoic ◽  
River Drainage ◽  
History Of ◽  
Southern Tibetan Plateau ◽  
Lhasa River ◽  
Topographic Evolution

The interaction of surface erosion (e.g., fluvial incision) and tectonic uplift shapes the landform in the Tibetan Plateau. The Lhasa River flows toward the southwest across the central Gangdese Mountains in the southern Tibetan Plateau, characterized by a low-relief and high-elevation landscape. However, the evolution of low-relief topography and the establishment of the Lhasa River remain highly under debate. Here, we collected thermochronological ages reported in the Lhasa River drainage, using a 3D thermokinematic model to invert both late Cenozoic denudation and relief history of the Lhasa River drainage. Our results show that the Lhasa River drainage underwent four-phase denudation history, including two-stage rapid denudation at ∼25–16 Ma (with a rate of ∼0.42 km/Ma) and ∼16–12 Ma (with a rate of ∼0.72 km/Ma). In the latest Oligocene–early Miocene, uplift of the Gangdese Mountains triggered the rapid denudation and the formation of the current main drainage of the Lhasa River. In the middle Miocene, the second stage of the rapid denudation and the high relief were associated with intense incision of the Lhasa River, which is probably due to the enhanced Asian summer monsoon precipitation. This later rapid episode was consistent with the records of regional main drainage systems. After ∼12 Ma, the denudation rate decreases rapidly, and the relief of topography in the central Gangdese region was gradually subdued. This indicates that the fluvial erosion resulting from Asian monsoon precipitation increase significantly impacts on the topographic evolution in the central Gangdese region.

Dynamics of evapotranspiration and variations in different land-cover regions over the Tibetan Plateau during 1961-2014

2021 ◽  
Author(s):  
Shan Lin ◽  
Genxu Wang ◽  
Zhaoyong Hu ◽  
Kewei Huang ◽  
Xiangyang Sun ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Land Cover ◽  
Northwestern Part ◽  
The Tibetan Plateau ◽  
Southeastern Part ◽  
Available Energy ◽  
Forest Region ◽  
Energy Factors ◽  
Term Change ◽  
Increasing Trend

AbstractIn this study, the spatiotemporal changes and driving factors of evapotranspiration (ET) over the Tibetan Plateau (TP) are assessed from 1961-2014, based on a revised generalized nonlinear complementary (nonlinear-CR) model. The average annual ET on the TP was 328 mm/year. The highest ET value (711 mm/year) was found in the forest region in the southeastern part of the TP, and the lowest value (151 mm/year) was found in the desert region in the northwestern part of the TP. In terms of the contribution of different sub-regions to the total amount of ET for the whole plateau, the meadow and steppe regions contributed the most to the total amount of ET of TP, accounting for 30% and 18.5%, respectively. The interannual ET presented a significant increasing trend with a value of 0.26 mm/year from 1961 to 2014, and a significant positive ET trend was found over 35% of the region, mainly in the southeastern part of the plateau. The increasing trend of ET in swamp areas was the largest, while that in the desert areas was the smallest. In terms of the seasonality, the ET over the plateau and different land-cover regions increased the most in summer, followed by spring, while the change in ET in winter was not obvious. The energy factors dominated the long-term change in the annual ET over the plateau. In addition, the available energy is the controlling factor for ET changes in humid areas such as forests and shrublands. Energy and water factors together dominate the ET changes in arid areas.

Initiation and Development of the Late Cenozoic Uplift of Daluo Mts, Northeastern Margin of the Tibetan Plateau

2022 ◽  
Author(s):  
Linlin KOU ◽  
Xiaopeng DONG ◽  
Zhenhong LI ◽  
Jiawei CUI ◽  
Zhaoying MA ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Late Cenozoic

scholarly journals Late Cenozoic evolution of the eastern margin of the Tibetan Plateau: Inferences from40Ar/39Ar and (U-Th)/He thermochronology

Tectonics ◽  
2002 ◽  
Vol 21 (1) ◽  
pp. 1-1-1-20 ◽  
Author(s):  
Eric Kirby ◽  
Peter W. Reiners ◽  
Michael A. Krol ◽  
Kelin X. Whipple ◽  
Kip V. Hodges ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Eastern Margin

scholarly journals Late Cenozoic continuous aridification in the western Qaidam Basin: evidence from sporopollen records

2013 ◽  
Vol 9 (2) ◽  
pp. 1485-1508 ◽  
Author(s):  
Y. F. Miao ◽  
X. M. Fang ◽  
F. L. Wu ◽  
M. T. Cai ◽  
C. H. Song ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Middle Miocene ◽  
Qaidam Basin ◽  
East Asian ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Plateau Uplift ◽  
Western Qaidam Basin ◽  
Global Cooling ◽  
Tibetan Plateau Uplift

Abstract. Cenozoic climate changes in inner Asia provide a basis for understanding linkages between global cooling, the Tibetan Plateau uplift, and possibly the development of the East Asian monsoon. Based on the compiled palynological results from the western Qaidam Basin, this study reconstructed an 18 Ma record of changing vegetation and paleoclimates since the middle Miocene. Thermophilic taxa percentages were highest between 18 and 14 Ma and decreased after 14 Ma, corresponding closely with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and the following global climatic cooling. After 3.6 Ma, the thermophilic taxa percentages further decreased, showing the inevitable relations with the ice-sheets enlargement in the North Hemisphere. During the same period of time, the increase in xerophytic taxa percentages and decrease in conifers percentages imply aridification in both the basin and surrounding mountains since 18 Ma. These results indicate that global cooling mainly controlled the climate change from a relative warm-wet stage to a cold-dry stage during the late Cenozoic at the western Qaidam Basin, and that the Tibetan Plateau uplift also contributed in contrast to the East Asian summer monsoon.

scholarly journals The Driving Forces Underlying Spatiotemporal Lake Extent Changes in the Inner Tibetan Plateau During the Holocene

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiangjun Liu ◽  
David Madsen ◽  
Xiaojian Zhang
Keyword(s):  
Tibetan Plateau ◽  
Lake Level ◽  
Climate Model ◽  
Driving Forces ◽  
Early Holocene ◽  
Water Vapor Transport ◽  
The Tibetan Plateau ◽  
Lake Levels ◽  
The Holocene ◽  
Spatial Differences

The Inner Tibetan Plateau (ITP), the central and western part of the Tibetan Plateau (TP), covers about one-fourth of the entire TP and contains more than 800 endorheic lakes larger than 1 km2. These lakes are important water reservoirs and sensitive to TP climate changes. They regulate regional water circulations, and further influence local ecosystems. Many lakes in ITP are surrounded by conspicuous paleoshorelines indicating much higher past lake levels. Previous studies found that lakes in the western ITP (west of ∼86°E) apparently expanded to higher levels than those to the east during the Holocene high lake level stage, however, there is no in-depth study on the reasons for the spatial differences of high lake levels within the ITP. In this study, we first identify Holocene lake level (or lake extent) changes over the ITP by combining published lake level variation data with our reconstruction of Dagze Co lake level variations. We then investigate spatial differences in the magnitude of lake expansions and explore the underlying forces driving these differences using the transient climate evolution of the last 21 ka (TraCE-21ka) and Kiel Climate Model (KCM) simulation results. We find that lakes in the ITP expanded to their highest levels during the early Holocene when the Indian summer monsoon (ISM) greatly intensified. After the mid-Holocene, lake levels fell as a result of the weakening of the ISM. The early Holocene northward shift of the westerly jet and a positive phase of the Atlantic multidecadal oscillation (AMO) resulted in the intensification of southwesterly winds on the southwest TP flank. Concurrently, westerly winds over the TP weakened, causing a differential increase in water vapor transport to the ITP with higher precipitation levels in the southwestern ITP and lower levels to the northeast. These wind-driven differential precipitation levels caused lakes in the southwestern ITP to expand to higher levels than those in the central, northern and northeastern ITP. During the early Holocene, expansion of lakes in the northwestern ITP was enhanced by an increase in glacier melt water besides the increased summer rainfall associated with the intensified ISM.

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