Microplastics in a Remote Lake Basin of the Tibetan Plateau: Impacts of Atmospheric Transport and Glacial Melting

2021 ◽  
Author(s):  
Huike Dong ◽  
Lanxiang Wang ◽  
Xiaoping Wang ◽  
Li Xu ◽  
Mengke Chen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Atmospheric Transport ◽  
Lake Basin ◽  
The Tibetan Plateau ◽  
Glacial Melting ◽  
Remote Lake

Origin and formation model of Eocene dolomite in the upper Niubao Formation of Lunpola Basin, Tibetan Plateau

2021 ◽  
pp. 1-50
Author(s):  
Xiaoquan Chen ◽  
Fengcun Xing ◽  
Shu Jiang ◽  
Yongchao Lu ◽  
Zhongrong Liu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Hot Springs ◽  
Northern China ◽  
Hydrothermal Fluids ◽  
Lake Basin ◽  
The Tibetan Plateau ◽  
Climate Conditions ◽  
Hot Climate ◽  
Strong Evaporation ◽  
Semi Arid

Using fresh cores samples, we determined the origin and formation process of Eocene lacustrine dolomites in the Tibetan Plateau through petrological, mineralogical, and geochemical analyses. Dolomitic rocks were collected from the upper member of Eocene Niubao Formation in the Lunpola Basin, and consist of dolomitic mudstone, argillaceous dolomite, dolomite-bearing mudstone and mud-bearing dolomite. These dolomites are dominated by aphanotopic and micro-crystalline dolomites, with minor amounts of euhedral or subhedral powder- and fine-crystalline dolomites. Carbon and oxygen stable isotopes, combined with ubiquitous gypsum in study area, indicates a semi-saline continental lake under strong evaporative conditions. The revealed relatively high temperature of dolomitization(33.8°C–119.1°C), combined with hydrothermal minerals such as cerous phosphate and barite, reflect the participation of dolomite from hot fluids. Moreover, the inferred dolomitization temperatures decrease gradually toward the centre of the lake basin, suggesting the resurgence of hydrothermal fluids along a fault zone on the lake margin. This proves that frequent thermal events occurred at the boundary fault of the Lunpola Basin margin during early Himalayan orogenesis. In addition, Jurassic carbonates interacting with hydrothermal fluids, as well as strong evaporation conditions, likely provided favourable conditions for the formation of primary lime sediments. A rich source of Mg2+ brought by volcanic ash, hydrothermal fluids, and the Jurassic carbonates then created conditions for dolomitization during the depositional period. Strong evaporation under a relatively hot climate enhanced penecontemporaneous dolomitization, thus forming dolomite. Tibetan Plateau was under arid to semi-arid climate conditions, and there was a widespread distribution of dolostones in western, central, and northern China during the Eocene period. The hydrothermal dolomites of the upper Niubao Formation testify for active hot springs, while lacustrine dolomite imply arid or semi-arid climates during the Eocene, in the early stages of Himalayan orogenesis.

Recent seismic events preserved in lacustrine sediments from the SE Tibetan Plateau

2020 ◽  
Author(s):  
Yongbo Wang ◽  
Xuezhi Ma ◽  
Zhenyu Ni
Keyword(s):  
Grain Size ◽  
Tibetan Plateau ◽  
Sediment Cores ◽  
Lacustrine Sediments ◽  
Size Composition ◽  
Recurrence Time ◽  
Seismic Events ◽  
Lake Basin ◽  
The Tibetan Plateau ◽  
Fine Clay

<p>Large earthquakes are regarded as important contributors to long-term erosion rates and considerable hazard to infrastructure and society, which were difficult to track because of the long recurrence time exceeding the time span of historical records. Geological records, especially the continuously accumulated lacustrine sediments, hold the potential to capture signals of prehistoric seismic events, which has been barely reported from the Tibetan Plateau. Here we present lacustrine sediment records recovered from Basom Tso in Southeastern Tibetan Plateau, in which two seismic events were preserved. Sediment lithology, grain size composition, magnetic susceptibility and XRF scanning induced element compositions showed dramatic variations in two turbidite-like sediment segments. Particularly, the grain size showed an abrupt increase at the bottom of the Turbidites which was followed by a fining-up pattern and covered by a fine clay cap, expressing similar sedimentary processes caused by the seiche effect triggered by seismic events. Consistent patterns were recorded in the element contents as well, i.e. obvious bias in the counts of Fe, Zr, Ti, Ca. In addition, scuh pattern were preserved in sediment cores from different part of the lake basin, indicating a basin wide event layer. Finally, according to the dating results from <sup>137</sup>Cs and <sup>14</sup>C, the two Turbidites were formed around 1950 A.D. and during the late18<sup>th</sup>/early 19<sup>th</sup> century respectively. Such information was further confirmed by historical earthquake records that Chayu Earthquake (M=8.6, 1950 A.D.) and Nyingchi Earthquake (M=6.75, 1845 A.D.) have possibly responsible for the slump of underwater sediments and the formation of these two turbidites.</p>

Long-Term Changes of Lake Level and Water Budget in the Nam Co Lake Basin, Central Tibetan Plateau

2014 ◽  
Vol 15 (3) ◽  
pp. 1312-1322 ◽  
Author(s):  
Yanhong Wu ◽  
Hongxing Zheng ◽  
Bing Zhang ◽  
Dongmei Chen ◽  
Liping Lei
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Water Budget ◽  
Lake Level ◽  
Lake Basin ◽  
The Tibetan Plateau ◽  
Nam Co ◽  
Long Term Changes ◽  
Nam Co Lake

Abstract Long-term changes in the water budget of lakes in the Tibetan Plateau due to climate change are of great interest not only for the importance of water management, but also for the critical challenge due to the lack of observations. In this paper, the water budget of Nam Co Lake during 1980–2010 is simulated using a dynamical monthly water balance model. The simulated lake level is in good agreement with field investigations and the remotely sensed lake level. The long-term hydrological simulation shows that from 1980 to 2010, lake level rose from 4718.34 to 4724.93 m, accompanied by an increase of lake water storage volume from 77.33 × 109 to 83.66 × 109 m3. For the net lake level rise (5.93 m) during the period 1980–2010, the proportional contributions of rainfall–runoff, glacier melt, precipitation on the lake, lake percolation, and evaporation are 104.7%, 56.6%, 41.7%, −22.2%, and −80.9%, respectively. A positive but diminishing annual water surplus is found in Nam Co Lake, implying a continuous but slowing rise in lake level as a hydrological consequence of climate change.

scholarly journals High-resolution modelling of interactions between soil moisture and convection development in mountain enclosed Tibetan basin

2015 ◽  
Vol 12 (5) ◽  
pp. 4631-4675
Author(s):  
T. Gerken ◽  
W. Babel ◽  
M. Herzog ◽  
K. Fuchs ◽  
F. Sun ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Energy Balance ◽  
Tibetan Plateau ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Local Development ◽  
Lake Basin ◽  
Strong Impact ◽  
The Tibetan Plateau ◽  
Moist Convection

Abstract. The Tibetan Plateau plays a significant role in the atmospheric circulation and the Asian monsoon system. Turbulent surface fluxes and the evolution of boundary layer clouds to deep and moist convection provide a feedback system that modifies the Plateau's surface energy balance on scales that are currently unresolved in mesoscale models. This work analyses the land surface's role and specifically the influence of soil moisture on the triggering of convection at a cross-section of the Nam Co Lake basin, 150 km north of Lhasa using a cloud resolving atmospheric model with a fully coupled surface. The modelled turbulent fluxes and development of convection compare reasonably well with the observed weather. The simulations span Bowen-ratios of 0.5 to 2.5. It is found that convection development is strongest at intermediate soil moistures. Dry cases with soils close to the permanent wilting point are moisture limited in the convection development, while convection in wet soil moisture cases is limited by cloud cover reducing incoming solar radiation and sensible heat fluxes. This has a strong impact on the surface energy balance. This study also shows that local development of convection is an important mechanism for the upward transport of water vapour that originates from the lake basin that can then be transported to dryer regions of the plateau. Both processes demonstrate the importance of soil moisture and surface–atmosphere interactions on the energy and hydrological cycles of the Tibetan Plateau.

scholarly journals Turbulent flux modelling with a simple 2-layer soil model and extrapolated surface temperature applied at Nam Co Lake basin on the Tibetan Plateau

2012 ◽  
Vol 16 (4) ◽  
pp. 1095-1110 ◽  
Author(s):  
T. Gerken ◽  
W. Babel ◽  
A. Hoffmann ◽  
T. Biermann ◽  
M. Herzog ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Surface Temperature ◽  
Temperature Profile ◽  
Circulation Model ◽  
Surface Model ◽  
Lake Basin ◽  
Base Temperature ◽  
The Tibetan Plateau ◽  
Nam Co ◽  
Nam Co Lake

Abstract. This paper introduces a surface model with two soil-layers for use in a high-resolution circulation model that has been modified with an extrapolated surface temperature, to be used for the calculation of turbulent fluxes. A quadratic temperature profile based on the layer mean and base temperature is assumed in each layer and extended to the surface. The model is tested at two sites on the Tibetan Plateau near Nam Co Lake during four days during the 2009 Monsoon season. In comparison to a two-layer model without explicit surface temperature estimate, there is a greatly reduced delay in diurnal flux cycles and the modelled surface temperature is much closer to observations. Comparison with a SVAT model and eddy covariance measurements shows an overall reasonable model performance based on RMSD and cross correlation comparisons between the modified and original model. A potential limitation of the model is the need for careful initialisation of the initial soil temperature profile, that requires field measurements. We show that the modified model is capable of reproducing fluxes of similar magnitudes and dynamics when compared to more complex methods chosen as a reference.

scholarly journals Accelerated lake expansion on the Tibetan Plateau in the 2000s: Induced by glacial melting or other processes?

2014 ◽  
Vol 50 (4) ◽  
pp. 3170-3186 ◽  
Author(s):  
Chunqiao Song ◽  
Bo Huang ◽  
Keith Richards ◽  
Linghong Ke ◽  
Vu Hien Phan
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Glacial Melting

scholarly journals Precipitation Dominates Long-Term Water Storage Changes in Nam Co Lake (Tibetan Plateau) Accompanied by Intensified Cryosphere Melts Revealed by a Basin-Wide Hydrological Modelling

2020 ◽  
Vol 12 (12) ◽  
pp. 1926
Author(s):  
Xiaoyang Zhong ◽  
Lei Wang ◽  
Jing Zhou ◽  
Xiuping Li ◽  
Jia Qi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Water Storage ◽  
Hydrological Processes ◽  
Lake Basin ◽  
Water Runoff ◽  
The Tibetan Plateau ◽  
Nam Co ◽  
Glacier Melting ◽  
Nam Co Lake

Lakes on the Tibetan Plateau (TP) have changed dramatically as a result of climate change during recent decades. Studying the changes in long-term lake water storage (LWS) is of great importance for regional water security and ecosystems. Nam Co Lake is the second largest lake in the central TP. To investigate the long-term changes in LWS, a distributed cryosphere-hydrology model (WEB-DHM) driven by multi-source data was evaluated and then applied to simulate hydrological processes across the whole Nam Co Lake basin from 1980 to 2016. Firstly, a comparison of runoff (lake inflow), land surface temperature, and snow depth between the model simulations and observations or remote sensing products showed that WEB-DHM could accurately simulate hydrological processes in the basin. Meanwhile, the simulated daily LWS was in good agreement with satellite-derived data during 2000–2016. Secondly, long-term simulations showed that LWS increased by 9.26 km3 during 1980–2016, reaching a maximum in 2010 that was 10.25 km3 greater than that in 1980. During this period, LWS firstly decreased (1980–1987), then increased (1988–2008), and decreased again (2009–2016). Thirdly, the contributions of precipitation runoff, melt-water runoff, lake surface precipitation, and lake evaporation to Nam Co LWS were 71%, 33%, 24%, and -28%, respectively. Snow and glacier melting have significantly intensified during recent decades (2.96 m3 s−1/decade on average), contributing a mean proportion of 22% of lake inflows. These findings are consistent with the significant increasing trends of annual precipitation and temperature in the lake basin (25 mm/decade and 0.4 K/decade, respectively). We conclude that long-term variations in Nam Co LWS during 1980–2016 were largely controlled by precipitation; however, the contribution of precipitation runoff to total lake inflow has decreased while the contribution from warming-induced snow and glacier melting has significantly increased.

scholarly journals High-resolution modelling of interactions between soil moisture and convective development in a mountain enclosed Tibetan Basin

2015 ◽  
Vol 19 (9) ◽  
pp. 4023-4040 ◽  
Author(s):  
T. Gerken ◽  
W. Babel ◽  
M. Herzog ◽  
K. Fuchs ◽  
F. Sun ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Energy Balance ◽  
Tibetan Plateau ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Local Development ◽  
Lake Basin ◽  
Strong Impact ◽  
The Tibetan Plateau ◽  
Moist Convection

Abstract. The Tibetan Plateau plays a significant role in atmospheric circulation and the Asian monsoon system. Turbulent surface fluxes and the evolution of boundary-layer clouds to deep and moist convection provide a feedback system that modifies the plateau's surface energy balance on scales that are currently unresolved in mesoscale models. This work analyses the land surface's role and specifically the influence of soil moisture on the triggering of convection at a cross section of the Nam Co Lake basin, 150 km north of Lhasa using a cloud-resolving atmospheric model with a fully coupled surface. The modelled turbulent fluxes and development of convection compare reasonably well with the observed weather. The simulations span Bowen ratios of 0.5 to 2.5. It is found that convective development is the strongest at intermediate soil moisture. Dry cases with soils close to the permanent wilting point are moisture limited in convective development, while convection in wet soil moisture cases is limited by cloud cover reducing incoming solar radiation and sensible heat fluxes, which has a strong impact on the surface energy balance. This study also shows that local development of convection is an important mechanism for the upward transport of water vapour, which originates from the lake basin that can then be transported to dryer regions of the plateau. Both processes demonstrate the importance of soil moisture and surface–atmosphere interactions on the energy and hydrological cycles of the Tibetan Plateau.

scholarly journals The Implication of Heat and Water Balance Changes in a Lake Basin on the Tibetan Plateau

2009 ◽  
Vol 3 ◽  
pp. 1-5 ◽  
Author(s):  
Jianqing Xu ◽  
Shumei Yu ◽  
Jingshi Liu ◽  
Shigenori Haginoya ◽  
Yasushi Ishigooka ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Water Balance ◽  
Lake Basin ◽  
The Tibetan Plateau
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