Extremely low long‐term erosion rates around the Gamburtsev Mountains in interior East Antarctica

Cox, Stephen E.; Thomson, S. N.; Reiners, Peter W.; Hemming, S. R.; Flierdt, Tina van de

doi:10.1029/2010gl045106

Cited by 53 publications

(65 citation statements)

References 38 publications

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“…Due to their altitude and therefore relatively thin (1–2 km) ice cover, ice sheet models (see section 4) predict these areas to be mostly frozen at the bed. The roughness of these landscapes suggests that they may be a partially preserved relic of an earlier alpine‐style glaciation of East Antarctica, largely unaffected by the present‐day slow ice flow in a manner similar to that postulated for the Gamburtsev Subglacial Mountains beneath Dome A [ Bo et al , 2009; Cox et al , 2010].…”

Section: Resultsmentioning

confidence: 99%

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

et al. 2012

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Subglacial hydrology in East Antarctica is poorly understood, yet may be critical to the manner in which ice flows. Data from a new regional airborne geophysical survey (ICECAP) have transformed our understanding of the topography and glaciology associated with the 287,000 km2 Aurora Subglacial Basin in East Antarctica. Using these data, in conjunction with numerical ice sheet modeling, we present a suite of analyses that demonstrate the potential of the 1000 km‐long basin as a route for subglacial water drainage from the ice sheet interior to the ice sheet margin. We present results from our analysis of basal topography, bed roughness and radar power reflectance and from our modeling of ice sheet flow and basal ice temperatures. Although no clear‐cut subglacial lakes are found within the Aurora Basin itself, dozens of lake‐like reflectors are observed that, in conjunction with other results reported here, support the hypothesis that the basin acts as a pathway allowing discharge from subglacial lakes near the Dome C ice divide to reach the coast via the Totten Glacier.

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Section: Resultsmentioning

confidence: 99%

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

et al. 2012

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“…Recent ground‐based radar work has found large, deeply incised valleys in the central GSM consistent with glacial steepening of existing stream valleys [ Bo et al ., ]. Long‐term erosion rates have been estimated to be as low as 0.01–0.02 km/Ma for the last 250 Ma [ Cox et al ., ]. This would correspond to the removal of 2.5–5 km of crustal material from the GSM over this period.…”

Section: Discussionmentioning

confidence: 99%

Rayleigh wave constraints on the structure and tectonic history of the Gamburtsev Subglacial Mountains, East Antarctica

et al. 2013

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[1] The Gamburtsev Subglacial Mountains (GSM), located near the center of East Antarctica, remain one of the most enigmatic mountain ranges on Earth. A lack of direct geologic samples renders their tectonic history almost totally unconstrained. We utilize teleseismic Rayleigh wave data from a 2 year deployment of broadband seismic stations across the region to image shear velocity structure and analyze the lithospheric age of the GSM and surrounding regions. We solve for 2-D phase velocities and invert these results for 3-D shear velocity structure. We perform a Monte Carlo simulation to improve constraints of crustal thickness and shear velocity structure. Beneath the core of the GSM, we find crustal thickness in excess of 55 km. Mantle shear velocities remain faster than global average models to a depth of approximately 250 km, indicating a thick lithospheric root. Thinner crust and slower upper mantle velocities are observed beneath the Lambert Rift System and the Polar Subglacial Basin. When compared with phase velocity curves corresponding to specific tectonothermal ages elsewhere in the world, average phase velocity results for the GSM are consistent with regions of Archean-Paleoproterozoic origin. Combined with radiometric ages of detrital zircons found offshore, these results indicate a region of old crust that has undergone repeated periods of uplift and erosion, most recently during the Mesozoic breakup of Gondwana. Lower crustal seismic velocities imply a moderately dense lower crust beneath the core of the GSM, but with lower density than suggested by recent gravity models.

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“…The extent of Antarctic glaciation prior to the EOT and whether Northern Hemisphere ice sheets existed before the Pliocene are two questions still subject to much debate [ Miller et al , 2005a; Pekar et al , 2005; Moran et al , 2006; Eldrett et al , 2007; Coxall and Pearson , 2007; Cox et al , 2010; Dawber and Tripati , 2011; Dawber et al , 2011]. Shackleton and Kennett [1975] used the δ 18 O record to hypothesize that a continent‐sized ice sheet first formed on Antarctica ∼15 Ma.…”

Section: Discussionmentioning

confidence: 99%

Exploring uncertainties in the relationship between temperature, ice volume, and sea level over the past 50 million years

Gasson¹,

Siddall²,

Lunt³

et al. 2012

Reviews of Geophysics

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[1] Over the past decade, efforts to estimate temperature and sea level for the past 50 Ma have increased. In parallel, efforts to model ice sheet changes during this period have been ongoing. We review published paleodata and modeling work to provide insights into how sea level responds to changing temperature through changes in ice volume and thermal expansion. To date, the temperature to sea level relationship has been explored for the transition from glacial to interglacial states. Attempts to synthesize the temperature to sea level relationship in deeper time, when temperatures were significantly warmer than present, have been tentative. We first review the existing temperature and sea level data and model simulations, with a discussion of uncertainty in each of these approaches. We then synthesize the sea level and temperature data and modeling results we have reviewed to test plausible forms for the sea level versus temperature relationship. On this very long timescale there are no globally representative temperature proxies, and so we investigate this relationship using deep-sea temperature records and surface temperature records from high and low latitudes. It is difficult to distinguish between the different plausible forms of the temperature to sea level relationship given the wide errors associated with the proxy estimates. We argue that for surface high-latitude Southern Hemisphere temperature and deep-sea temperature, the rate of change of sea level to temperature has not remained constant, i.e., linear, over the past 50 Ma, although the relationship remains ambiguous for the available low-latitude surface temperature data. A nonlinear form between temperature and sea level is consistent with ice sheet modeling studies. This relationship can be attributed to (1) the different glacial thresholds for Southern Hemisphere glaciation compared to Northern Hemisphere glaciation and (2) the ice sheet carrying capacity of the Antarctic continent.

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Extremely low long‐term erosion rates around the Gamburtsev Mountains in interior East Antarctica

Cited by 53 publications

References 38 publications

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

Rayleigh wave constraints on the structure and tectonic history of the Gamburtsev Subglacial Mountains, East Antarctica

Exploring uncertainties in the relationship between temperature, ice volume, and sea level over the past 50 million years

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