scholarly journals GNSS Imaging of Strain Rate Changes and Vertical Crustal Motions over the Tibetan Plateau

2021 ◽  
Vol 13 (23) ◽  
pp. 4937
Author(s):  
Yunfei Xiang ◽  
Hao Wang ◽  
Yuanyuan Chen ◽  
Yin Xing
Keyword(s):  
Tibetan Plateau ◽  
Strain Rate ◽  
Tarim Basin ◽  
Three Dimensional ◽  
Indian Plate ◽  
The Tibetan Plateau ◽  
Eurasian Plate ◽  
Himalayan Belt ◽  
Low Altitude ◽  
Main Factor

In this paper, we perform a comprehensive analysis of contemporary three-dimensional crustal deformations over the Tibetan Plateau. Considering that the coverage of continuous GNSS sites in the Tibetan Plateau is sparse, a newly designed method that mainly contains Spatial Structure Function (SSF) construction and Median Spatial Filtering (MSF) is adopted to conduct GNSS imaging of point-wise velocities, which can well reveal the spatial pattern of vertical crustal motions. The result illustrates that the Himalayan belt bordering Nepal appears significant uplift at the rates of ~3.5 mm/yr, while the low-altitude regions of Nepal and Bhutan near the Tibetan Plateau are undergoing subsidence. The result suggests that the subduction of the Indian plate is the driving force of the uplift and subsidence in the Himalayan belt and its adjacent regions. Similarly, the thrusting of the Tarim Basin is the main factor of the slight uplift and subsidence in the Tianshan Mountains and Tarim Basin, respectively. In addition, we estimate the strain rate changes over the Tibetan Plateau using high-resolution GNSS horizontal velocities. The result indicates that the Himalayan belt and southeastern Tibetan Plateau have accumulated a large amount of strain rate due to the Indian-Eurasian plate collision and blockage of the South China block, respectively.

scholarly journals Spatio-Temporal Variation Characteristics of Snow Depth and Snow Cover Days over the Tibetan Plateau

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 307
Author(s):  
Chi Zhang ◽  
Naixia Mou ◽  
Jiqiang Niu ◽  
Lingxian Zhang ◽  
Feng Liu
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Snow Depth ◽  
Feedback Effect ◽  
Effect Of Temperature ◽  
The Tibetan Plateau ◽  
Reanalysis Dataset ◽  
Spatio Temporal ◽  
The Impact ◽  
Main Factor

Changes in snow cover over the Tibetan Plateau (TP) have a significant impact on agriculture, hydrology, and ecological environment of surrounding areas. This study investigates the spatio-temporal pattern of snow depth (SD) and snow cover days (SCD), as well as the impact of temperature and precipitation on snow cover over TP from 1979 to 2018 by using the ERA5 reanalysis dataset, and uses the Mann–Kendall test for significance. The results indicate that (1) the average annual SD and SCD in the southern and western edge areas of TP are relatively high, reaching 10 cm and 120 d or more, respectively. (2) In the past 40 years, SD (s = 0.04 cm decade−1, p = 0.81) and SCD (s = −2.3 d decade−1, p = 0.10) over TP did not change significantly. (3) The positive feedback effect of precipitation is the main factor affecting SD, while the negative feedback effect of temperature is the main factor affecting SCD. This study improves the understanding of snow cover change and is conducive to the further study of climate change on TP.

scholarly journals Ancient mitogenomes show plateau populations from last 5200 years partially contributed to present-day Tibetans

2020 ◽  
Vol 287 (1923) ◽  
pp. 20192968 ◽  
Author(s):  
Manyu Ding ◽  
Tianyi Wang ◽  
Albert Min-Shan Ko ◽  
Honghai Chen ◽  
Hui Wang ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Deep Learning ◽  
Tibetan Plateau ◽  
High Altitude ◽  
Simulation Models ◽  
The Tibetan Plateau ◽  
Limited Evidence ◽  
Complete Continuity ◽  
Genetic Origins ◽  
Low Altitude

The clarification of the genetic origins of present-day Tibetans requires an understanding of their past relationships with the ancient populations of the Tibetan Plateau. Here we successfully sequenced 67 complete mitochondrial DNA genomes of 5200 to 300-year-old humans from the plateau. Apart from identifying two ancient plateau lineages (haplogroups D4j1b and M9a1a1c1b1a) that suggest some ancestors of Tibetans came from low-altitude areas 4750 to 2775 years ago and that some were involved in an expansion of people moving between high-altitude areas 2125 to 1100 years ago, we found limited evidence of recent matrilineal continuity on the plateau. Furthermore, deep learning of the ancient data incorporated into simulation models with an accuracy of 97% supports that present-day Tibetan matrilineal ancestry received partial contribution rather than complete continuity from the plateau populations of the last 5200 years.

Spring Dust Mass Flux over the Tibetan Plateau during 2007–19 and Connections with North Atlantic SST Variability

2020 ◽  
Vol 33 (22) ◽  
pp. 9691-9703
Author(s):  
Chao Xu ◽  
Yaoming Ma ◽  
Jiehua Ma ◽  
Chao You ◽  
Huijun Wang
Keyword(s):  
Tibetan Plateau ◽  
North Atlantic ◽  
Tarim Basin ◽  
Mass Flux ◽  
The Tibetan Plateau ◽  
Indian Peninsula ◽  
The North ◽  
Dust Mass ◽  
The North Atlantic ◽  
Spring Dust

AbstractDust is the major aerosol type over the Tibetan Plateau (TP), and the TP plays an important role in forming the spring dust belt across the Northern Hemisphere in the upper troposphere. Estimated spring dust mass flux (DMF) showed a significant declining trend over the TP during 2007–19. The total spring DMF across the TP (TDMFTP) was mainly affected by DMFs over the Tarim Basin, while the spring DMF across the TP in the midtroposphere was also connected with DMFs over the northwest Indian Peninsula and central Asia. Interannual variability of spring TDMFTP was strongly correlated with the North Atlantic winter sea surface temperature (SST) tripole. A cold preceding winter induced by the North Atlantic winter SST tripole over midlatitude Eurasia promotes dust activities in the subsequent spring. The North Atlantic winter SST tripole anomalies persist into the subsequent spring and induce a corresponding atmosphere response. Enhanced atmospheric baroclinicity develops over northwest China and the northern Indian Peninsula during spring, which is attributed to surface thermal forcing induced by the positive winter SST tripole phase. A strong positive North Atlantic winter SST tripole anomaly strengthens the upper-level westerly jets, enhancing airflow toward the TP midtroposphere; together, these circulation patterns cause anomalous cyclonic conditions in the lower troposphere, especially over the Tarim Basin, via the eastward propagation of a Rossby wave train. These atmospheric circulation conditions are likely to increase the frequency of dust occurrence and promote the transport of dust onto the TP.

Adjoint Tomography of the Lithospheric Structure beneath Northeastern Tibet

2020 ◽  
Vol 91 (6) ◽  
pp. 3304-3312
Author(s):  
Xingpeng Dong ◽  
Dinghui Yang ◽  
Hejun Zhu
Keyword(s):  
Tibetan Plateau ◽  
Indian Plate ◽  
Tectonic Deformation ◽  
Lithospheric Structure ◽  
The Tibetan Plateau ◽  
S Wave ◽  
Low Velocity ◽  
Northeastern Tibet ◽  
Adjoint Tomography ◽  
Indian Lithosphere

Abstract Northeastern Tibet is still in the primary stage of tectonic deformation and is the key area for studying the lateral expansion of the Tibetan plateau. In particular, the existence of lower crustal flow, southward subduction of the Asian lithosphere, and northward subduction of the Indian lithosphere beneath northeastern Tibet remains controversial. To provide insights into these issues, a high-resolution 3D radially anisotropic model of the lithospheric structure of northeastern Tibet is developed based on adjoint tomography. The Tibetan plateau is characterized as a low S-wave velocity lithosphere, in contrast with the relatively high S-wave velocities of the stable Asian blocks. Our tomographic result indicates that the low-velocity zone (LVZ) within the deep crust extends northeastward from Songpan–Ganzi to Qilian, which is interpreted as a channel flow within the crust. The upper mantle of Alxa and Qinling–Qilian are dominated by a rather homogeneous LVZ, which is inconsistent with the hypothesis that the Asian lithospheric mantle is being subducted southward beneath northeastern Tibet. Furthermore, high-velocity regions are observed in the southern Songpan–Ganzi region at depths ranging from 100 to 200 km, indicating that the northward-subducting Indian plate has probably reached the Xianshuihe fault.

scholarly journals Land use and land cover change detection and spatial distribution on the Tibetan Plateau

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuang Hao ◽  
Fengshun Zhu ◽  
Yuhuan Cui
Keyword(s):  
Land Use ◽  
Tibetan Plateau ◽  
Land Cover ◽  
Change Detection ◽  
Dynamic Change ◽  
Coniferous Forest ◽  
Three Dimensional ◽  
Detection Methods ◽  
Land Cover Changes ◽  
The Tibetan Plateau

AbstractRegarded as the third pole of the Earth, the Tibetan Plateau (TP) is a region with complex terrain. Vegetation is widely distributed in the southeastern part of the plateau. However, the land use and land cover changes (LULCC) on the TP have not been sufficiently studied. In this study, we propose a method of studying the dynamic changes in the land cover on the TP. Landsat OLI images (2013 and 2015) were selected to extract the LULCC information of Nyingchi County, the DEM was used to extract objects’ land curved surface area and analyze their three-dimensional dynamic change information, which realized a four-dimensional monitoring of the forestry information on time and spatial level. The results showed that the forest area in 2015 decreased by 7.25%, of which the coniferous forest areas decreased by 25.14%, broad-leaved forest areas increased by 12.65%, and shrubbery areas increased by 14.62%. Compared with traditional LULCC detection methods, the change detection is no longer focused on the two-dimensional space, which helps determine the three-dimensional land use and land cover changes and their distribution. Thus, dynamic spatial changes can be observed. This study provides scientific support for the vegetation restoration and natural resource management on the TP.

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