Variability of basal melt beneath the Pine Island Glacier ice shelf, West Antarctica

Bindschadler, Robert; Vaughan, David G.; Vornberger, Patricia

doi:10.3189/002214311797409802

Cited by 83 publications

(146 citation statements)

References 24 publications

Supporting

Mentioning

124

Contrasting

Unclassified

Order By: Relevance

“…A number of ice shelves have been observed to have channel-like incisions at their base, oriented roughly in the direction of ice flow (Rignot & Steffen 2008;Bindschadler et al 2011;Vaughan et al 2012;LeBrocq et al 2013). Observationally inferred basal melt rates are enhanced within the channels compared to the neighbouring thicker ice (Rignot & Steffen 2008;Dutrieux et al 2013), and plumes containing a mixture of entrained warm deep waters and ice shelf melt have been observed to emerge from under Pine Island ice shelf in the vicinity of larger channels (Mankoff et al 2012).…”

Section: Introductionmentioning

confidence: 97%

Channelization of plumes beneath ice shelves

2015

View full text Add to dashboard Cite

We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

show abstract

Section: Introductionmentioning

confidence: 97%

Channelization of plumes beneath ice shelves

2015

View full text Add to dashboard Cite

show abstract

“…2e) by imposing hydrostatic equilibrium on surface freeboard (Bindschadler et al, 2011b;Chuter and Bamber, 2015;Drews, 2015) derived from the TanDEM-X satellites. The details of hydrostatic inversion are presented in the following two sections.…”

Section: Hydrostatic Ice Thicknessmentioning

confidence: 99%

Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica

et al. 2017

View full text Add to dashboard Cite

Abstract. Ice shelves control the dynamic mass loss of ice sheets through buttressing and their integrity depends on the spatial variability of their basal mass balance (BMB), i.e. the difference between refreezing and melting. Here, we present an improved technique -based on satellite observations -to capture the small-scale variability in the BMB of ice shelves. As a case study, we apply the methodology to the Roi Baudouin Ice Shelf, Dronning Maud Land, East Antarctica, and derive its yearly averaged BMB at 10 m horizontal gridding. We use mass conservation in a Lagrangian framework based on high-resolution surface velocities, atmosphericmodel surface mass balance and hydrostatic ice-thickness fields (derived from TanDEM-X surface elevation). Spatial derivatives are implemented using the total-variation differentiation, which preserves abrupt changes in flow velocities and their spatial gradients. Such changes may reflect a dynamic response to localized basal melting and should be included in the mass budget. Our BMB field exhibits much spatial detail and ranges from −14.7 to 8.6 m a −1 ice equivalent. Highest melt rates are found close to the grounding line where the pressure melting point is high, and the ice shelf slope is steep. The BMB field agrees well with on-site measurements from phase-sensitive radar, although independent radar profiling indicates unresolved spatial variations in firn density. We show that an elliptical surface depression (10 m deep and with an extent of 0.7 km × 1.3 km) lowers by 0.5 to 1.4 m a −1 , which we tentatively attribute to a transient adaptation to hydrostatic equilibrium. We find evidence for elevated melting beneath ice shelf channels (with melting being concentrated on the channel's flanks). However, farther downstream from the grounding line, the majority of ice shelf channels advect passively (i.e. no melting nor refreezing) toward the ice shelf front. Although the absolute, satellite-based BMB values remain uncertain, we have high confidence in the spatial variability on sub-kilometre scales. This study highlights expected challenges for a full coupling between ice and ocean models.

show abstract

“…En consecuencia, en numerosas áreas de la PA los glaciares han mostrado una tendencia acelerada hacia la pérdida de volumen (Cook et al, 2005;Pritchard y Vaughan, 2007;Cook y Vaughan, 2010). La pérdida de hielo se está produciendo a través del adelgazamiento de las masas glaciares (Jenkins et al, 2010), el retroceso de las paredes de los frentes glaciares (Rignot et al, 2014) y la fusión basal por la inyección de aguas más cálidas en la base de las plataformas de hielo marinas (Bindschadler et al, 2011;Jacobs et al, 2011;Pritchard et al, 2012).…”

Section: Introductionunclassified

La deglaciación de las áreas libres de hielo de las islas Shetland del Sur (Antártida). Ejemplos de Byers (Livingston) y Barton (King George)

Oliva

Antoniades

Giralt³

et al. 2016

CyG

View full text Add to dashboard Cite

The process of deglaciation of the present-day ice-free environments in the Maritime Antarctica has profound geomorphological and ecological implications. However, the timing of glacier retreat is still poorly understood. This is the case of the deglaciated areas existing in Byers (Livingston Island) and Barton (King George Island) peninsulas. The dating of the basal sediments collected from different lakes in these two peninsulas allowed inferences of the ages of formation of each lake. The integration of these ages enables the reconstruction ofthe spatial and temporal pattern of deglaciation of these areas. The chronological framework has been establishedusing two complementary techniques: radiocarbon and thermoluminescence dating. In both peninsulas the deglaciation started during the Early Holocene, around 8 ka cal BP. The areas located far away from the current ice domes and the highest peaks in the two peninsulas (nunataks) were the first areas to become ice -free. During the mid-Holocene (5-6 ka cal BP) the central part of these peninsulas was progressively deglaciated. Finally, during the Late Holocene glacier fronts remained confined to the current position defined by the present frontal moraines, with minor advances and retreats.

show abstract

Variability of basal melt beneath the Pine Island Glacier ice shelf, West Antarctica

Cited by 83 publications

References 24 publications

Channelization of plumes beneath ice shelves

Channelization of plumes beneath ice shelves

Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica

La deglaciación de las áreas libres de hielo de las islas Shetland del Sur (Antártida). Ejemplos de Byers (Livingston) y Barton (King George)

Contact Info

Product

Resources

About