Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ocean-induced melt volume directly paces ice loss from Pine Island Glacier

ABSTRACT: Description Glacier response to ice-shelf thinning is driven largely by the total melt rather than its spatial distribution. The spatial distribution of ocean-induced melting beneath buttressing ice shelves is often cited as an important factor controlling Antarctica’s sea-level contribution. Using numerical simulations, we investigate the relative sensitivity of grounded-ice loss to the spatial distribution and overall volume of ice-shelf melt over two centuries. Contrary to earlier work, we find only minor sensitivity to melt distribution (<6%), with a linear dependence of ice loss on the total melt. Thus, less complex models that need not reproduce the detailed melt distribution may simplify the projection of future sea level. The linear sensitivity suggests a contribution of up to 5.1 cm from Pine Island Glacier over the next two centuries given anticipated levels of ocean warming, provided its ice shelf does not collapse because of other causes.

SUBMITTER: Joughin I

PROVIDER: S-EPMC8535793 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Diverse landscapes beneath Pine Island Glacier influence ice flow.

Project description:The retreating Pine Island Glacier (PIG), West Antarctica, presently contributes ~5-10% of global sea-level rise. PIG's retreat rate has increased in recent decades with associated thinning migrating upstream into tributaries feeding the main glacier trunk. To project future change requires modelling that includes robust parameterisation of basal traction, the resistance to ice flow at the bed. However, most ice-sheet models estimate basal traction from satellite-derived surface velocity, without a priori knowledge of the key processes from which it is derived, namely friction at the ice-bed interface and form drag, and the resistance to ice flow that arises as ice deforms to negotiate bed topography. Here, we present high-resolution maps, acquired using ice-penetrating radar, of the bed topography across parts of PIG. Contrary to lower-resolution data currently used for ice-sheet models, these data show a contrasting topography across the ice-bed interface. We show that these diverse subglacial landscapes have an impact on ice flow, and present a challenge for modelling ice-sheet evolution and projecting global sea-level rise from ice-sheet loss.

| S-EPMC5696374 | biostudies-literature

Ice-shelf retreat drives recent Pine Island Glacier speedup.

Project description:Speedup of Pine Island Glacier over the past several decades has made it Antarctica's largest contributor to sea-level rise. The past speedup is largely due to grounding-line retreat in response to ocean-induced thinning that reduced ice-shelf buttressing. While speeds remained fairly steady from 2009 to late 2017, our Copernicus Sentinel 1A/B-derived velocity data show a >12% speedup over the past 3 years, coincident with a 19-km retreat of the ice shelf. We use an ice-flow model to simulate this loss, finding that accelerated calving can explain the recent speedup, independent of the grounding-line, melt-driven processes responsible for past speedups. If the ice shelf's rapid retreat continues, it could further destabilize the glacier far sooner than would be expected due to surface- or ocean-melting processes.

| S-EPMC8195478 | biostudies-literature

Mechanisms driving variability in the ocean forcing of Pine Island Glacier.

Project description:Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG and nearby glaciers. However, the variability of the ocean forcing of PIG has been poorly constrained due to a lack of multi-year observations. Here we show, using a unique record close to the Pine Island Ice Shelf (PIIS), that there is considerable oceanic variability at seasonal and interannual timescales, including a pronounced cold period from October 2011 to May 2013. This variability can be largely explained by two processes: cumulative ocean surface heat fluxes and sea ice formation close to PIIS; and interannual reversals in ocean currents and associated heat transport within Pine Island Bay, driven by a combination of local and remote forcing. Local atmospheric forcing therefore plays an important role in driving oceanic variability close to PIIS.

| S-EPMC5321733 | biostudies-literature

Regularized Coulomb Friction Laws for Ice Sheet Sliding: Application to Pine Island Glacier, Antarctica.

Project description:The choice of the best basal friction law to use in ice-sheet models remains a source of uncertainty in projections of sea level. The parameters in commonly used friction laws can produce a broad range of behavior and are poorly constrained. Here we use a time series of elevation and speed data to examine the simulated transient response of Pine Island Glacier, Antarctica, to a loss of basal traction as its grounding line retreats. We evaluate a variety of friction laws, which produces a diversity of responses, to determine which best reproduces the observed speedup when forced with the observed thinning. Forms of the commonly used power law friction provide much larger model-data disagreement than less commonly used regularized Coulomb friction in which cavitation effects yield an upper bound on basal friction. Thus, adoption of such friction laws could substantially improve the fidelity of large-scale simulations to determine future sea level.

| S-EPMC6582595 | biostudies-literature

Ocean variability beneath Thwaites Eastern Ice Shelf driven by the Pine Island Bay Gyre strength.

Project description:West Antarctic ice-shelf thinning is primarily caused by ocean-driven basal melting. Here we assess ocean variability below Thwaites Eastern Ice Shelf (TEIS) and reveal the importance of local ocean circulation and sea-ice. Measurements obtained from two sub-ice-shelf moorings, spanning January 2020 to March 2021, show warming of the ice-shelf cavity and an increase in meltwater fraction of the upper sub-ice layer. Combined with ocean modelling results, our observations suggest that meltwater from Pine Island Ice Shelf feeds into the TEIS cavity, adding to horizontal heat transport there. We propose that a weakening of the Pine Island Bay gyre caused by prolonged sea-ice cover from April 2020 to March 2021 allowed meltwater-enriched waters to enter the TEIS cavity, which increased the temperature of the upper layer. Our study highlights the sensitivity of ocean circulation beneath ice shelves to local atmosphere-sea-ice-ocean forcing in neighbouring open oceans.

| S-EPMC9772408 | biostudies-literature

Heterogeneous retreat and ice melt of Thwaites Glacier, West Antarctica.

Project description:The glaciers flowing into the Amundsen Sea Embayment, West Antarctica, have undergone acceleration and grounding line retreat over the past few decades that may yield an irreversible mass loss. Using a constellation of satellites, we detect the evolution of ice velocity, ice thinning, and grounding line retreat of Thwaites Glacier from 1992 to 2017. The results reveal a complex pattern of retreat and ice melt, with sectors retreating at 0.8 km/year and floating ice melting at 200 m/year, while others retreat at 0.3 km/year with ice melting 10 times slower. We interpret the results in terms of buoyancy/slope-driven seawater intrusion along preferential channels at tidal frequencies leading to more efficient melt in newly formed cavities. Such complexities in ice-ocean interaction are not currently represented in coupled ice sheet/ocean models.

| S-EPMC6353628 | biostudies-literature

Glacier thickness and ice volume of the Northern Andes

Project description:Tropical glacier melt provides valuable water to surrounding communities, but climate change is projected to cause the demise of many of these glaciers within the coming century. Understanding the future of tropical glaciers requires a detailed record of their thicknesses and volumes, which is currently lacking in the Northern Andes. We calculate present-day (2015–2021) ice-thicknesses for all glaciers in Colombia and Ecuador using six different methods, and combine these into multi-model ensemble mean ice thickness and volume maps. We compare our results against available field-based measurements, and show that current ice volumes in Ecuador and Colombia are 2.49 ± 0.25 km3 and 1.68 ± 0.24 km3 respectively. We detected no motion on any remaining ice in Venezuela. The overall ice volume in the region, 4.17 ± 0.35 km3, is half of the previous best estimate of 8.11 km3. These data can be used to better evaluate the status and distribution of water resources, as input for models of future glacier change, and to assess regional geohazards associated with ice-clad volcanoes. Measurement(s)Glacier ThicknessTechnology Type(s)Velocity based inversionFactor Type(s)Ice thicknessSample Characteristic - EnvironmentglacierSample Characteristic - LocationNorthern Andes

| S-EPMC9200720 | biostudies-literature

Tracking the Cracking: A Holistic Analysis of Rapid Ice Shelf Fracture Using Seismology, Geodesy, and Satellite Imagery on the Pine Island Glacier Ice Shelf, West Antarctica.

Project description:Ice shelves regulate the stability of marine ice sheets. We track fractures on Pine Island Glacier, a quickly accelerating glacier in West Antarctica that contributes more to sea level rise than any other glacier. Using an on-ice seismic network deployed from 2012 to 2014, we catalog icequakes that dominantly consist of flexural gravity waves. Icequakes occur near the rift tip and in two distinct areas of the shear margin, and TerraSAR-X imagery shows significant fracture in each source region. Rift-tip icequakes increase with ice speed, linking rift fracture to glaciological stresses and/or localized thinning. Using a simple flexural gravity wave model, we deconvolve wave propagation effects to estimate icequake source durations of 19.5-50.0 s and transient loads of 3.8-14.0 kPa corresponding to 4.3-15.9 m of crevasse growth per icequake. These long-source durations suggest that water flow may limit the rate of crevasse opening.

| S-EPMC9285369 | biostudies-literature

Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica.

Project description:Mass loss from the Antarctic ice sheet, Earth's largest freshwater reservoir, results directly in global sea-level rise and Southern Ocean freshening. Observational and modeling studies have demonstrated that ice shelf basal melting, resulting from the inflow of warm water onto the Antarctic continental shelf, plays a key role in the ice sheet's mass balance. In recent decades, warm ocean-cryosphere interaction in the Amundsen and Bellingshausen seas has received a great deal of attention. However, except for Totten Ice Shelf, East Antarctic ice shelves typically have cold ice cavities with low basal melt rates. Here we present direct observational evidence of high basal melt rates (7-16 m yr-1) beneath an East Antarctic ice shelf, Shirase Glacier Tongue, driven by southward-flowing warm water guided by a deep continuous trough extending to the continental slope. The strength of the alongshore wind controls the thickness of the inflowing warm water layer and the rate of basal melting.

| S-EPMC7445286 | biostudies-literature

Evidence of an active volcanic heat source beneath the Pine Island Glacier.

Project description:Tectonic landforms reveal that the West Antarctic Ice Sheet (WAIS) lies atop a major volcanic rift system. However, identifying subglacial volcanism is challenging. Here we show geochemical evidence of a volcanic heat source upstream of the fast-melting Pine Island Ice Shelf, documented by seawater helium isotope ratios at the front of the Ice Shelf cavity. The localization of mantle helium to glacial meltwater reveals that volcanic heat induces melt beneath the grounded glacier and feeds the subglacial hydrological network crossing the grounding line. The observed transport of mantle helium out of the Ice Shelf cavity indicates that volcanic heat is supplied to the grounded glacier at a rate of ~ 2500 ± 1700 MW, which is ca. half as large as the active Grimsvötn volcano on Iceland. Our finding of a substantial volcanic heat source beneath a major WAIS glacier highlights the need to understand subglacial volcanism, its hydrologic interaction with the marine margins, and its potential role in the future stability of the WAIS.

| S-EPMC6014989 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data