Melting and refreezing beneath Roi Baudouin Ice Shelf (East Antarctica) inferred from radar, GPS, and ice core data

Pattyn, Frank; Matsuoka, Kenichi; Callens, Denis; Conway, H.; Depoorter, Mathieu; Docquier, David; Hubbard, Bryn; Samyn, Denis; Tison, Jean-Louis

doi:10.1029/2011jf002154

Cited by 20 publications

(16 citation statements)

References 73 publications

(104 reference statements)

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“…Precise comparison of OPTV luminosity and snow/firn density is not possible for the NEEM shallow hole because density data are not available for this core at a sufficiently high resolution for detailed comparison. However, this potential is being investigated in detail as part of ongoing studies based on cores recovered from the Roi Baudouin ice shelf, Antarctica (Hubbard and others, 2012; Pattyn and others, 2012).…”

Section: Resultsmentioning

confidence: 99%

Optical-televiewer-based logging of the uppermost 630 m of the NEEM deep ice borehole, Greenland

Hubbard

Malone

2013

Ann. Glaciol.

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We report on the application of optical televiewing (OPTV) to the uppermost 630m of the North Greenland Eemian Ice Drilling (NEEM) deep ice borehole, Greenland. The resulting log reveals numerous natural and drilling-related properties, including the integrity of the borehole casing and its joints, the presence of drill-tooth scoring on the ice wall of the borehole and the presence of regularly repeated layering, interpreted to be annual, to a depth approaching 200m. A second OPTV log was acquired from a nearby shallow borehole. With the exception of the uppermost 10m, this log shows a gradual decrease in luminosity with depth, interpreted as a decrease in light scattering with firnification. This shallow log also clearly images annual layers, allowing the construction of an age?depth scale. Comparing this with an independent core-based scale reveals that the OPTV record yields an age of 1724 at the deepest common point of both scales (80m), 13 years older than the core-based record at 1737. However, all of this deviation accrues in the uppermost 30m of the OPTV record where highly reflective snow saturates the luminosity of the borehole image, an artefact that can be reduced by further adaptation of the OPTV system.Peer reviewe

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Section: Resultsmentioning

confidence: 99%

Optical-televiewer-based logging of the uppermost 630 m of the NEEM deep ice borehole, Greenland

Hubbard

Malone

2013

Ann. Glaciol.

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“…Lokeryggen Promontory (#44) bounds the western edge of the Roi Baudouin Ice Shelf at 24.6°E. It has a saddle and a seaward dome summit where the ice thickness reaches ~600 m (Matsuoka and others, 2012; Pattyn and others, 2012). The rough bed underneath this ice rise makes it difficult to identify Raymond arches from its undulating englacial stratigraphy.…”

Section: The Dml and Enderby Land Coastsmentioning

confidence: 99%

Characteristics of ice rises and ice rumples in Dronning Maud Land and Enderby Land, Antarctica

et al. 2020

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Ice rises and rumples, locally grounded features adjacent to ice shelves, are relatively small yet play significant roles in Antarctic ice dynamics. Their roles generally depend upon their location within the ice shelf and the stage of the ice-sheet retreat or advance. Large, long-stable ice rises can be excellent sites for deep ice coring and paleoclimate study of the Antarctic coast and the Southern Ocean, while small ice rises tend to respond more promptly and can be used to reveal recent changes in regional mass balance. The coasts of Dronning Maud Land (DML) and Enderby Land in East Antarctica are abundant with these features. Here we review existing knowledge, presenting an up-to-date status of research in these regions with focus on ice rises and rumples. We use regional datasets (satellite imagery, surface mass balance and ice thickness) to analyze the extent and surface morphology of ice shelves and characteristic timescales of ice rises. We find that large parts of DML have been changing over the past several millennia. Based on our findings, we highlight ice rises suitable for drilling ice cores for paleoclimate studies as well as ice rises suitable for deciphering ice dynamics and evolution in the region.

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“…This accretion process can be active in large areas of lower draft and smooth subsurface topography if the supply of supercooled melt water is sufficient, such as in the central part of the Ronne Ice Shelf [ Thyssen , ]. Marine ice originating from deposition of frazil ice crystals has also been observed in ice shelf rift systems, where it can contribute to what is referred to as an “ice mélange,” which also contains debris from the rift shoulders [e.g., MacAyeal et al ., ; Tison et al ., ; Khazendar et al ., ; Khazendar and Jenkins , ; Pattyn et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Marine ice formation in a suture zone on the Larsen C Ice Shelf and its influence on ice shelf dynamics

et al. 2013

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[1] Antarctic ice shelves are fed primarily by the glaciers flowing into them. Downstream of promontories separating these glaciers, supercooled water can rise and freeze into suture zones, leading to the accretion of marine ice. Marine ice bodies have been found in several Antarctic ice shelves, but little is known about their detailed geometry, rate of accretion, or influence on ice dynamics. In this study, we investigate marine ice in a suture zone downstream of the Joerg Peninsula in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula. We present ground penetrating radar data from which we infer the base of the meteoric ice and, in combination with GPS data and assuming hydrostatic equilibrium, estimate marine ice thickness within a suture zone. We show that the Joerg Peninsula suture zone contains marine ice layer, which is increasing in thickness along flow from~140 m to 180 m over 20 km, implying an average basal accretion rate of 0.5 m a À1 in our study area. We examined the impact of this inferred marine ice on ice shelf dynamics by modeling the suture zone within an ice flow model. The results, which replicate observed surface velocities and strain rates, show that the warmer and thus softer ice of the suture zone serves to channel shear deformation. This enables decoupling of neighboring flow units with different flow velocities, while maintaining the structural integrity of the ice shelf.

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Melting and refreezing beneath Roi Baudouin Ice Shelf (East Antarctica) inferred from radar, GPS, and ice core data

Cited by 20 publications

References 73 publications

Optical-televiewer-based logging of the uppermost 630 m of the NEEM deep ice borehole, Greenland

Optical-televiewer-based logging of the uppermost 630 m of the NEEM deep ice borehole, Greenland

Characteristics of ice rises and ice rumples in Dronning Maud Land and Enderby Land, Antarctica

Marine ice formation in a suture zone on the Larsen C Ice Shelf and its influence on ice shelf dynamics

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