Towards ice thickness inversion: an evaluation of global DEMs by ICESat-2 in the glacierized Tibetan Plateau

Abstract. Accurate estimates of regional ice thickness, which are generally produced by ice-thickness inversion models, are crucial for assessments of available freshwater resources and sea level rise. Digital elevation model (DEM) derived surface topography of glaciers is a primary data source for such models. However, the scarce in-situ measurements of glacier surface elevation limit the evaluation of DEM uncertainty, and hence its influence on ice-thickness modelling over the glacierized area of the Tibetan Plateau (TP). Here, we examine the performance over the glacierized TP of six widely used and mainly global-scale DEMs: AW3D30 (30 m), SRTM-GL1 (30 m), NASADEM (30 m), TanDEM-X (90 m), SRTM v4.1 (90 m) and MERIT (90 m) by using ICESat-2 laser altimetry data while considering the effects of glacier dynamics, terrain, and DEM misregistration. The results reveal NASADEM as the best performer, with a small mean error (ME) of −1.0 and a root mean squared error (RMSE) of 12.6 m. A systematic vertical offset existed in AW3D30 (−35.3 ME and 34.9 m RMSE), although it had a similar relative accuracy to NASADEM (~ 13 m STD). TanDEM-X also performs well (−0.1 ME and 15.1 m RMSE), but suffers from serious errors and outliers on steep slopes. SRTM-based DEMs (SRTM-GL1, SRTM v4.1, and MERIT) (all ~ 36 m RMSE) had an inferior performance to NASADEM. However, their errors were reduced in the ablation zone when glacier variations were excluded. Errors in the six DEMs increased from the south-facing to the north-facing aspect and become larger with increasing slope. Misregistration of DEMs relative to ICESat-2 footprint in most glacier areas is small (less than one pixel). An intercomparison of four ice-thickness models: GlabTop2, Open Global Glacier Model (OGGM), Huss-Farinotti (HF), Ice Thickness Inversion Based on Velocity (ITIBOV), show that GlabTop2 is sensitive to the accuracy of both elevation and slope, while OGGM and HF are less sensitive to DEM quality, and ITIBOV is the most sensitive to slope accuracy. Considering the inconsistency of DEMs acquisition dates, NASADEM would be a best choice for ice-thickness estimates over the TP, followed by AW3D30, and TanDEM-X (if steep and high elevation terrain can be avoided). Our assessment figures out the performances of mainly global DEMs over the glacierized TP. This study not only avails the glacier thickness estimation with ice thickness inversion models, but also offered references for other cryosphere studies using DEM.

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Roof of the World: Tibet, Pamirs

Colliding Continents ◽

10.1093/oso/9780199653003.003.0016 ◽

2013 ◽

Author(s):

Mike Searle

Keyword(s):

Tibetan Plateau ◽

High Elevation ◽

Tien Shan ◽

Palm Tree ◽

The Tibetan Plateau ◽

Wet Season ◽

North West ◽

Mountain Ranges ◽

The North ◽

The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

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Size distribution of PM20 observed to the north of the Tibetan Plateau

Journal of Mountain Science ◽

10.1007/s11629-020-6086-3 ◽

2021 ◽

Vol 18 (2) ◽

pp. 367-376

Author(s):

Cheng-long Zhou ◽

Fan Yang ◽

Wen Huo ◽

Ali Mamtimin ◽

Xing-hua Yang

Keyword(s):

Tibetan Plateau ◽

Size Distribution ◽

The Tibetan Plateau ◽

The North

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Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau

Nature Communications ◽

10.1038/s41467-021-24415-y ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Maoliang Zhang ◽

Zhengfu Guo ◽

Sheng Xu ◽

Peter H. Barry ◽

Yuji Sano ◽

...

Keyword(s):

Tibetan Plateau ◽

Growth Dynamics ◽

High Elevation ◽

Fault System ◽

The Tibetan Plateau ◽

Southeastern Tibetan Plateau ◽

Surface Uplift ◽

Multi Stage ◽

Geodynamic Processes ◽

Underlying Mechanisms

AbstractThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.

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A new species of Cleistocybe (Agaricales, Basidiomycota) from the Tibetan Plateau, China

Phytotaxa ◽

10.11646/phytotaxa.336.3.7 ◽

2018 ◽

Vol 336 (3) ◽

pp. 286 ◽

Cited By ~ 2

Author(s):

HONG-MEI WU ◽

JIA-QI LUO ◽

KE WANG ◽

RUN-CHAO ZHANG ◽

YI LI ◽

...

Keyword(s):

New Species ◽

Tibetan Plateau ◽

Phylogenetic Analyses ◽

Morphological Observation ◽

Morphological Description ◽

The Tibetan Plateau ◽

Sequence Analyses ◽

The North ◽

Close Relationship ◽

A New Species

During field expeditions to the Tibetan Plateau, a collection of an undescribed species with several basidiomes was found. Morphological observation and DNA sequence analyses of the collection revealed a close relationship with Cleistocybe vernalis, the type species of the genus Cleistocybe. Therefore, a new species is proposed for the fungus with full morphological description accompanied by phylogenetic analyses. The discovery of the species extends the reported distribution of the genus from the north of America and Europe to Asia.

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“Tiny wiggles” in the Late Miocene red clay deposits in the north‐east of the Tibetan Plateau

Geophysical Research Letters ◽

10.1029/2021gl093962 ◽

2021 ◽

Author(s):

Rui Zhang ◽

Xiaohao Wei ◽

Vadim A. Kravchinsky ◽

Leping Yue ◽

Yan Zheng ◽

...

Keyword(s):

Tibetan Plateau ◽

Late Miocene ◽

The Tibetan Plateau ◽

Red Clay ◽

North East ◽

The North ◽

Clay Deposits

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Melting Ice Rivers

Dirty, Sacred Rivers ◽

10.1093/oso/9780199845019.003.0011 ◽

2012 ◽

Author(s):

Cheryl Colopy

Keyword(s):

Global Warming ◽

Tibetan Plateau ◽

The Netherlands ◽

Sea Level ◽

The Tibetan Plateau ◽

Mount Everest ◽

The Past ◽

The North ◽

The World ◽

The Government

From a remote outpost of global warming, a summons crackles over a two-way radio several times a week: . . . Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! . . . In a little brick building on the lip of a frigid gray lake fifteen thousand feet above sea level, Ram Bahadur Khadka tries to rouse someone at Nepal’s Department of Hydrology and Meteorology in the Babar Mahal district of Kathmandu far below. When he finally succeeds and a voice crackles back to him, he reads off a series of measurements: lake levels, amounts of precipitation. A father and a farmer, Ram Bahadur is up here at this frigid outpost because the world is getting warmer. He and two colleagues rotate duty; usually two of them live here at any given time, in unkempt bachelor quarters near the roof of the world. Mount Everest is three valleys to the east, only about twenty miles as the crow flies. The Tibetan plateau is just over the mountains to the north. The men stay for four months at a stretch before walking down several days to reach a road and board a bus to go home and visit their families. For the past six years each has received five thousand rupees per month from the government—about $70—for his labors. The cold, murky lake some fifty yards away from the post used to be solid ice. Called Tsho Rolpa, it’s at the bottom of the Trakarding Glacier on the border between Tibet and Nepal. The Trakarding has been receding since at least 1960, leaving the lake at its foot. It’s retreating about 200 feet each year. Tsho Rolpa was once just a pond atop the glacier. Now it’s half a kilometer wide and three and a half kilometers long; upward of a hundred million cubic meters of icy water are trapped behind a heap of rock the glacier deposited as it flowed down and then retreated. The Netherlands helped Nepal carve out a trench through that heap of rock to allow some of the lake’s water to drain into the Rolwaling River.

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First mid-ocean ridge-type ophiolite from the Meso-Tethys suture zone in the north-central Tibetan plateau

Geological Society of America Bulletin ◽

10.1130/b35500.1 ◽

2020 ◽

Vol 132 (9-10) ◽

pp. 2202-2220 ◽

Cited By ~ 5

Author(s):

Yue Tang ◽

Qing-Guo Zhai ◽

Sun-Lin Chung ◽

Pei-Yuan Hu ◽

Jun Wang ◽

...

Keyword(s):

Tibetan Plateau ◽

Ocean Basin ◽

Suture Zone ◽

The Tibetan Plateau ◽

Spreading Ridge ◽

North Central ◽

The North ◽

Central Tibetan Plateau ◽

Mid Ocean Ridge ◽

Ocean Ridge

Abstract The Meso-Tethys was a late Paleozoic to Mesozoic ocean basin between the Cimmerian continent and Gondwana. Part of its relicts is exposed in the Bangong–Nujiang suture zone, in the north-central Tibetan Plateau, that played a key role in the evolution of the Tibetan plateau before the India-Asia collision. A Penrose-type ophiolitic sequence was newly discovered in the Ren Co area in the middle of the Bangong–Nujiang suture zone, which comprises serpentinized peridotites, layered and isotropic gabbros, sheeted dikes, pillow and massive basalts, and red cherts. Zircon U-Pb dating of gabbros and plagiogranites yielded 206Pb/238U ages of 169–147 Ma, constraining the timing of formation of the Ren Co ophiolite. The mafic rocks (i.e., basalt, diabase, and gabbro) in the ophiolite have uniform geochemical compositions, coupled with normal mid-ocean ridge basalt-type trace element patterns. Moreover, the samples have positive whole-rock εNd(t) [+9.2 to +8.3], zircon εHf(t) [+17 to +13], and mantle-like δ18O (5.8–4.3‰) values. These features suggest that the Ren Co ophiolite is typical of mid-ocean ridge-type ophiolite that is identified for the first time in the Bangong–Nujiang suture zone. We argue that the Ren Co ophiolite is the relic of a fast-spreading ridge that occurred in the main oceanic basin of the Bangong–Nujiang segment of Meso-Tethys. Here the Meso-Tethyan orogeny involves a continuous history of oceanic subduction, accretion, and continental assembly from the Early Jurassic to Early Cretaceous.

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