Viscous and elastic buoyancy stresses as drivers of ice-shelf calving

Mosbeux, Cyrille; Wagner, Thomas; Becker, M. K.; Fricker, H. A.

doi:10.1017/jog.2020.35

Cited by 18 publications

(32 citation statements)

References 57 publications

(92 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Warmer sea surface temperatures lead to the melt of fast ice, which destabilizes glacier margins (Larour, 2004) and could result in retreat. Another explanation proposes that warm surface water increases melt at the waterline, which creates an overhanging ice cliff that is more likely to collapse (Mosbeux et al, 2020). Our results suggest that increased sea surface temperatures weakened the margins in the Bellingshausen and Amundsen sea sectors, where the highest increases in sea surface temperature were observed.…”

Section: A Circum-antarctic Perspectivementioning

confidence: 61%

“…The combined influence of those factors make it challenging to create a realistic calving law, making iceberg calving still one of the least understood ice shelf processes (Bassis, 2011). Frontal retreat starts with the formation of a crevasse originating from a strain rate surpassing the yield stress of ice (Mosbeux et al, 2020). For ice shelves and floating glacier tongues, the calving position evolves where crevasses develop into through-cutting fractures (rifts).…”

Section: Is Calculatedmentioning

confidence: 99%

“…For ice shelves and floating glacier tongues, the calving position evolves where crevasses develop into through-cutting fractures (rifts). These ice shelf rifts can propagate further into the ice front or intersect with other rifts, resulting in a tabular iceberg calving event (Benn et al, 2007;Joughin and MacAyeal, 2005), where the extent of the ice shelf and the size of the iceberg are defined by the rift location (Lipovsky, 2020;Mosbeux et al, 2020;Walker et al, 2013). Further boundary conditions such as fjord geometry (Alley et al, 2008;Catania et al, 2018), ice rises and rumples (Matsuoka et al, 2015), and bed topography (Hughes, 1981) influence the stability of the calving margin.…”

Section: Is Calculatedmentioning

confidence: 99%

See 2 more Smart Citations

Environmental drivers of circum-Antarctic glacier and ice shelf front retreat over the last two decades

et al. 2021

View full text Add to dashboard Cite

Abstract. The safety band of Antarctica, consisting of floating glacier tongues and ice shelves, buttresses ice discharge of the Antarctic Ice Sheet. Recent disintegration events of ice shelves along with glacier retreat indicate a weakening of this important safety band. Predicting calving front retreat is a real challenge due to complex ice dynamics in a data-scarce environment that are unique for each ice shelf and glacier. We explore the extent to which easy-to-access remote sensing and modeling data can help to define environmental conditions leading to calving front retreat. For the first time, we present a circum-Antarctic record of glacier and ice shelf front change over the last two decades in combination with environmental variables such as air temperature, sea ice days, snowmelt, sea surface temperature, and wind direction. We find that the Antarctic Ice Sheet area decreased by −29 618 ± 1193 km2 in extent between 1997–2008 and gained an area of 7108 ± 1029 km2 between 2009 and 2018. Retreat concentrated along the Antarctic Peninsula and West Antarctica including the biggest ice shelves (Ross and Ronne). In several cases, glacier and ice shelf retreat occurred in conjunction with one or several changes in environmental variables. Decreasing sea ice days, intense snowmelt, weakening easterlies, and relative changes in sea surface temperature were identified as enabling factors for retreat. In contrast, relative increases in mean air temperature did not correlate with calving front retreat. For future studies a more appropriate measure for atmospheric forcing should be considered, including above-zero-degree days and temperature extreme events. To better understand drivers of glacier and ice shelf retreat, it is critical to analyze the magnitude of basal melt through the intrusion of warm Circumpolar Deep Water that is driven by strengthening westerlies and to further assess surface hydrology processes such as meltwater ponding, runoff, and lake drainage.

show abstract

Section: A Circum-antarctic Perspectivementioning

confidence: 61%

Section: Is Calculatedmentioning

confidence: 99%

Section: Is Calculatedmentioning

confidence: 99%

See 1 more Smart Citation

Environmental drivers of circum-Antarctic glacier and ice shelf front retreat over the last two decades

et al. 2021

View full text Add to dashboard Cite

show abstract

“…ICESat and ROSETTA-Ice (airborne) altimetry data revealed a "rampart-moat" structure along icebergs that calved from the Ronne Ice Shelf and parts of the Ross Ice Shelf, respectively (Mosbeux et al, 2020;Scambos et al, 2005). This feature, which includes a several-meter-deep depression ("moat") typically <1 km inboard of a raised edge ("rampart"), is caused by wave-driven and thermal erosion of the front near the waterline, and the subsequent formation of a buoyant submerged bench of ice (Mosbeux et al, 2020;Scambos et al, 2005;Wagner et al, 2014Wagner et al, , 2016. The resulting stress imbalance can eventually lead to the calving of a small "sliver-shaped iceberg" (Kristensen, 1983).…”

Section: Changes In Amery Ice Frontmentioning

confidence: 99%

A High Resolution, Three‐Dimensional View of the D‐28 Calving Event From Amery Ice Shelf With ICESat‐2 and Satellite Imagery

Walker

Becker

Fricker

2021

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Tabular calving events occur from Antarctica's large ice shelves only every few decades, and are preceded by rift propagation. We used high‐resolution imagery and ICESat‐2 data to determine the propagation rates for the three active rifts on Amery Ice Shelf (AIS; T1, T2, and E3) and observe the calving of D‐28 on September 25, 2019 along T1. AIS front advance accelerated downstream of T1 in the years before calving, possibly increasing stress at the rift tip. T1 experienced significant acceleration for 12 days before calving, coinciding with a jump in propagation of E3. ICESat‐2's high resolution and repeat acquisitions every 91 days allowed for analysis of the ice front before and after calving, and rift detection where it was not visible in imagery as a ∼1 m surface depression, suggesting that it propagates as a basal fracture. Our results show that ICESat‐2 can provide process‐scale information about iceberg calving.

show abstract

“…Another explanation proposes that warm surface water increases melt at the waterline which creates an overhanging ice cliff that is more likely to collapse (Mosbeux et al, 2020).…”

Section: A Circum-antarctic Perspectivementioning

confidence: 99%

Driving Forces of Circum-Antarctic Glacier and Ice Shelf Front Retreat over the Last Two Decades

Baumhoer

Dietz

Kneisel

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. The safety band of Antarctica consisting of floating glacier tongues and ice shelves buttresses ice discharge of the Antarctic Ice Sheet. Recent disintegration events of ice shelves and glacier retreat indicate a weakening of this important safety band. Predicting calving front retreat is a real challenge due to complex ice dynamics in a data-scarce environment being unique for each ice shelf and glacier. We explore to what extent easy to access remote sensing and modelling data can help to define environmental conditions leading to calving front retreat. For the first time, we present a circum-Antarctic record of glacier and ice shelf front retreat over the last two decades in combination with environmental variables such as air temperature, sea ice days, snowmelt, sea surface temperature and wind direction. We find that the Antarctic ice sheet area shrank 29,618 ± 29 km2 in extent between 1997–2008 and gained an area of 7,108 ± 144.4 km2 between 2009 and 2018. Retreat concentrated along the Antarctic Peninsula and West Antarctica including the biggest ice shelves Ross and Ronne. Glacier and ice shelf retreat comes along with one or several changes in environmental variables. Decreasing sea ice days, intense snow melt, weakening easterlies and relative changes in sea surface temperature were identified as enabling factors for retreat. In contrast, relative increases in air temperature did not correlate with calving front retreat. To better understand drivers of glacier and ice shelf retreat it is of high importance to analyse the magnitude of basal melt through the intrusion of warm Circumpolar Deep Water (CDW) driven by strengthening westerlies and to further assess surface hydrology processes such as meltwater ponding, runoff and lake drainage.

show abstract

Viscous and elastic buoyancy stresses as drivers of ice-shelf calving

Cited by 18 publications

References 57 publications

Environmental drivers of circum-Antarctic glacier and ice shelf front retreat over the last two decades

Environmental drivers of circum-Antarctic glacier and ice shelf front retreat over the last two decades

A High Resolution, Three‐Dimensional View of the D‐28 Calving Event From Amery Ice Shelf With ICESat‐2 and Satellite Imagery

Driving Forces of Circum-Antarctic Glacier and Ice Shelf Front Retreat over the Last Two Decades

Contact Info

Product

Resources

About