Geodetic signatures of a Late Pleistocene Tibetan ice sheet

Kaufmann, Georg

doi:10.1016/j.jog.2004.08.005

Cited by 13 publications

(20 citation statements)

References 37 publications

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“…If the former is true then the effect of GIA on present-day uplift rates is negligible. For the latter, surface uplift rates of 1 -2 mm yr -1 are expected for the majority of the plateau (Wang 2001;Kaufmann 2005). Figure 7 shows current GIA models for the Tibetan Plateau.…”

Section: Pleistocene Deglaciationmentioning

confidence: 99%

“…Figure 7 shows current GIA models for the Tibetan Plateau. Figure 7 (upper left panel) shows the predicted GIA uplift using the KUHLE ice model (Kuhle 1998), and KL1 Earth model (Kaufmann 2005). Figure 7 (upper right panel) shows the predicted GIA uplift for ice model TIBET4, with Earth model KL1 (Kaufmann 2005).…”

Section: Pleistocene Deglaciationmentioning

confidence: 99%

“…Figure 7 (upper left panel) shows the predicted GIA uplift using the KUHLE ice model (Kuhle 1998), and KL1 Earth model (Kaufmann 2005). Figure 7 (upper right panel) shows the predicted GIA uplift for ice model TIBET4, with Earth model KL1 (Kaufmann 2005). Figure 7 (lower left panel) shows the predicted GIA uplift for ice model TIBET6, with Earth model KL1 (Kaufmann 2005).…”

Section: Pleistocene Deglaciationmentioning

confidence: 99%

“…The size and extent of the hypothesized Pleistocene ice-sheet is still being debated (Derbyshire et al 1991). Various glaciation scenarios have been recently discussed in the literature and their expected GIA signals have been modeled (Wang 2001;Kaufmann 2005).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

Erkan¹,

Shum²,

Wang³

et al. 2011

Terr. Atmos. Ocean. Sci.

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The Qinghai-Tibetan Plateau is the largest and the highest area in the world with distinct and competing surface and subsurface processes. The entire Plateau has been undergoing crustal deformation and accompanying isostatic uplift as a result of the Cenozoic collision of the Indian and Eurasian continents. Regional secular surface mass changes include the melting of mountain glaciers and ice caps, and permafrost layer degradation due to global warming. There is also a plausible effect of glacial isostatic adjustment due to the removal of a possible Pleistocene ice-sheet. In this article, we present an assessment of the sizes and extents of these competing interior and exterior dynamical processes, and their possible detections using contemporary space geodetic techniques. These techniques include, in addition to GPS, satellite radar altimetry over land, and temporal gravity field measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. These techniques are complementary: land satellite altimetry, similar to GPS, is sensitive only to surface uplift, whereas GRACE is sensitive to both surface uplift and mass changes inside the Earth. Each process may dominate the others in a particular region. Our analysis shows that GRACE data are more sensitive (than GPS or land altimetry) to hydrologic and meteorology signals, some of which are larger than the combined effect of geodynamic processes and permafrost degradation.

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Section: Pleistocene Deglaciationmentioning

confidence: 99%

Section: Pleistocene Deglaciationmentioning

confidence: 99%

Section: Pleistocene Deglaciationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

Erkan¹,

Shum²,

Wang³

et al. 2011

Terr. Atmos. Ocean. Sci.

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“…Therefore, we only consider the GIA effect caused by the LGM below. Wang (2001) and Kaufmann (2005) discussed GIA effects on vertical displacement and the gravity rate of change in the Tibetan area. Based on the ice model of Kuhle et al (1990), Wang (2001) computed the GIA effects for four viscosity models.…”

Section: Gia Effects Contributed In the Secular Gravity Changesmentioning

confidence: 99%

A Reinvestigation of Crustal Thickness in the Tibetan Plateau Using Absolute Gravity, GPS and GRACE Data

Sun¹,

Wang²,

Li³

et al. 2011

Terr. Atmos. Ocean. Sci.

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The geodetic evidence of the uplift and crustal thickness of the Tibetan Plateau has been presented for the first time (Sun et al. 2009) using gravity and GPS observations. In this paper, we reinvestigate this tectonic deformation in more detail using GRACE data and taking the GIA effect into account. We first summarize the previous gravity and GPS observations and a local gravity network in the Dali County. The comparison between the surface absolute gravity and space GRACE gravity measurements shows that they are harmonic, agree well. Finally, we assume that the residual gravity change reflects material transport accompanying vertical movements on the crustal bottom; the crustal thickening rate is inferred as 1.9 ± 1.4 cm yr -1 . As the crust thickens, the mass of a column of rock beneath the station decreases because mantle is displaced by crust, causing a reduction in gravity.

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Effects of Gaussian filter in processing GRACE data: Gravity rate of change at Lhasa, southern Tibet

Sun

Hasegawa

Zhang

et al. 2011

Sci. China Earth Sci.

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In this paper, the spatial gravity distribution over Tibetan Plateau and the gravity rate of change at Lhasa for different Gaussian filter radii are computed using GRACE data. Results show that the estimate of the gravity rate of change is spatialradius-dependent of the Gaussian filter. The GRACE-estimated gravity rate of change agrees well with the surface measured one. In other words, the GRACE-estimated gravity rate of change has a limited value as that obtained by surface measurement when the spatial filter radius reaches zero. Then numerical simulations are made for different spatial radii of the Gaussian filter to investigate its behaviors when applied to surface signals. Results show that the estimate of a physical signal is filter-radius dependent. If the computing area is equal to or less than the mass area, especially for a uniformly distributed mass, the estimate gives an almost correct result, no matter what filter radius is used. The estimate has large error because of the signal leakage caused by harmonic truncation if the computing area is much bigger than the mass distribution (or inverse for a small mass anomaly). If a mass anomaly is too small, it is difficult to recover it from space observation unless the filter radius is extremely small. If the computing point (or area) is outside the mass distribution, the estimated result is almost zero, particularly for small filter radii. These properties of the Gaussian filter are helpful in applying GRACE data in different geophysical problems with different spatial position and geometrical size. We further discuss physical sources causing the scalar gravity change at Lhasa. Discussions indicate that the gravity rate of change at Lhasa is not caused by the present-day ice melting (PDIM) (or Little Ice Age, LIA) effect because no ice melting occurs in Lhasa city and nearby. The gravity rate of change is attributable mainly to tectonic deformation associated with the Indian Plate collision. Simultaneous surface displacement, surface denudation, and GIA effects are not negligible. gravity change, GRACE, Gaussian filter, Tibetan Plateau, Lhasa

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Geodetic signatures of a Late Pleistocene Tibetan ice sheet

Cited by 13 publications

References 37 publications

Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

A Reinvestigation of Crustal Thickness in the Tibetan Plateau Using Absolute Gravity, GPS and GRACE Data

Effects of Gaussian filter in processing GRACE data: Gravity rate of change at Lhasa, southern Tibet

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