PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Pine Island Glacier sensitive to climatic variability

2014-01-03
(Press-News.org) Contact information: Paul Seagrove
psea@bas.ac.uk
44-122-322-1414
British Antarctic Survey
Pine Island Glacier sensitive to climatic variability A new study published in Science this month suggests the thinning of Pine Island Glacier in West Antarctica is much more susceptible to climatic and ocean variability than at first thought. Observations by a team of scientists at British Antarctic Survey, and other institutions, show large fluctuations in the ocean heat in Pine Island Bay. The team discovered that oceanic melting of the ice shelf into which the glacier flows decreased by 50 per cent between 2010 and 2012, and this may have been due to a La Ninã weather event. Pine Island Glacier has thinned continuously during past decades driven by an acceleration in its flow. The acceleration is thought to be caused by thinning of the floating ice shelf created as the glacier slides into the sea. Understanding the processes driving ice shelf thinning and the glacier's response is key to assessing how much it will contribute to rising sea levels. It's now known that much of the thinning is due to a deep oceanic inflow of Circumpolar Deep Water (CDW) on the continental shelf neighbouring the glacier. This warmer water then makes its way into a cavity beneath the ice shelf melting it from below. The passage of this warmer water was made easier by the unpinning of the ice shelf from an underwater ridge. The ridge had, in effect, acted as a wall preventing warmer water from getting to the thickest part of the shelf. This ungrounding event was one of the major driving forces behind the glacier's rapid change. In 2009, a higher CDW volume and temperature in Pine Island Bay contributed to an increase in ice shelf melting compared to the last time measurements were taken in 1994. But observations made in January 2012, and reported now in Science, show that ocean melting of the glacier was the lowest ever recorded. The top of the thermocline (the layer separating cold surface water and warm deep waters) was found to be about 250 metres deeper compared with any other year for which measurements exist. This lowered thermocline reduces the amount of heat flowing over the ridge. High resolution simulations of the ocean circulation in the ice shelf cavity demonstrate that the ridge blocks the deepest ocean waters from reaching the thickest ice. So its presence enhances the ice shelf's sensitivity to climate variability since any changes in the thermocline can alter the amount of heat filtering through. The fluctuations in temperature recorded by the team may be explained by particular climatic conditions. In January 2012 the dramatic cooling of the ocean around the glacier is believed to be due to an increase in easterly winds caused by a strong La Ninã event in the tropical Pacific Ocean. Normally the winds flow from the west. The observations suggest there is a complex interplay between geological, oceanographic and climatic processes. The study stresses the importance of both local geology and climate variability in ocean melting in this region. Lead author, Dr Pierre Dutrieux, from British Antarctic Survey (BAS) said: "We found ocean melting of the glacier was the lowest ever recorded, and less than half of that observed in 2010. This enormous, and unexpected, variability contradicts the widespread view that a simple and steady ocean warming in the region is eroding the West Antarctic Ice Sheet. These results demonstrate that the sea-level contribution of the ice sheet is influenced by climatic variability over a wide range of time scales." Co-author, Professor Adrian Jenkins, also from BAS, added: "It is not so much the ocean variability, which is modest by comparison with many parts of the ocean, but the extreme sensitivity of the ice shelf to such modest changes in ocean properties that took us by surprise. That sensitivity is a result of a submarine ridge beneath the ice shelf that was only discovered in 2009 when an Autonomous Underwater Vehicle mapped the seabed beneath the ice. These new insights suggest that the recent history of ice shelf melting and thinning has been much more variable than hitherto suspected and susceptible to climate variability driven from the tropics." ### Issued by the British Antarctic Survey Press Office.


ELSE PRESS RELEASES FROM THIS DATE:

Molecule discovered that protects the brain from cannabis intoxication

2014-01-03
Molecule discovered that protects the brain from cannabis intoxication Two INSERM research teams led by Pier Vincenzo Piazza and Giovanni Marsicano (INSERM Unit 862 "Neurocentre Magendie" in Bordeaux) ...

Animal cells can communicate by reaching out and touching, UCSF team discovers

2014-01-03
Animal cells can communicate by reaching out and touching, UCSF team discovers Signaling through direct contact not restricted to neurons, as previously thought In a finding that directly contradicts the standard biological model of animal cell ...

Study explaining parasite gene expression could help fight toxoplasmosis and malaria

2014-01-03
Study explaining parasite gene expression could help fight toxoplasmosis and malaria INDIANAPOLIS -- A newly identified protein and other proteins it interacts with could become effective targets for new drugs to control the parasite that cause toxoplasmosis, researchers ...

Men's and women's soccer: Physical or technical?

2014-01-03
Men's and women's soccer: Physical or technical? A comparative study into the performance of men and women players in UEFA Champions League matches suggests that women and men each play soccer 'in their own way' This news release is available in Spanish. When the ...

Genetically identical bacteria can behave in radically different ways

2014-01-03
Genetically identical bacteria can behave in radically different ways Uneven distribution of certain mechanisms during cell division creates diversity that can enhance a bacterial population's survival Although a population of bacteria may be genetically identical, individual ...

Patch outperforms Holter for prolonged heart rhythm tracking

2014-01-03
Patch outperforms Holter for prolonged heart rhythm tracking Scripps study suggests shift in decades-old practice for detecting irregular heart beats SAN DIEGO – Research by the Scripps Translational Science Institute (STSI) has found that a small adhesive wireless ...

Researchers report technique that enables patient with 'word blindness' to read again

2014-01-03
Researchers report technique that enables patient with 'word blindness' to read again MAYWOOD, Il. - In the journal Neurology, researchers report a novel technique that enables a patient with "word blindness" to read again. Word blindness is a rare neurological ...

Odor receptors discovered in lungs

2014-01-03
Odor receptors discovered in lungs They're just like those in your nose but instead of conjuring up a cup of coffee they might make you cough Your nose is not the only organ in your body that can sense cigarette smoke wafting through the air. Scientists at Washington ...

Local factors cause dramatic spikes in coastal ocean acidity

2014-01-03
Local factors cause dramatic spikes in coastal ocean acidity Fluctuation 'adds insult to injury' for marine creatures DURHAM, N.C. – A new Duke University-led study has documented dramatic, natural short-term increases in the acidity of a North Carolina estuary. "The natural ...

EARTH Magazine: Geological travels in Antarctica

2014-01-03
EARTH Magazine: Geological travels in Antarctica Following in the footsteps of giants Alexandria, VA – Yesterday, 52 scientists, journalists and tourists were rescued from frozen Antarctic waters, where their ship, the MV Akademik Shokalskiy, had been stuck ...

LAST 30 PRESS RELEASES:

Inability to pay for healthcare reaches record high in U.S.

Science ‘storytelling’ urgently needed amid climate and biodiversity crisis

KAIST Develops Retinal Therapy to Restore Lost Vision​

Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response

Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid

Low LDL cholesterol levels linked to reduced risk of dementia

Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients

Almost one in ten people surveyed report having been harmed by the NHS in the last three years

Enhancing light control with complex frequency excitations

New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients

New insight into factors associated with a common disease among dogs and humans

Illuminating single atoms for sustainable propylene production

New study finds Rocky Mountain snow contamination

Study examines lactation in critically ill patients

UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award

Doubling down on metasurfaces

New Cedars-Sinai study shows how specialized diet can improve gut disorders

Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana

PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation

ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy

How VR technology is changing the game for Alzheimer’s disease

A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet

Balance between two competing nerve proteins deters symptoms of autism in mice

Use of antifungals in agriculture may increase resistance in an infectious yeast

Awareness grows of cancer risk from alcohol consumption, survey finds

The experts that can outsmart optical illusions

Pregnancy may reduce long COVID risk

Scientists uncover novel immune mechanism in wheat tandem kinase

Three University of Virginia Engineering faculty elected as AAAS Fellows

Unintentional drug overdoses take a toll across the U.S. unequally, study finds

[Press-News.org] Pine Island Glacier sensitive to climatic variability