Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antarctic Peninsula ice more stable than thought

02.05.2017

Glacier flow at the southern Antarctic Peninsula has increased since the 1990s, but a new study has found the change to be only a third of what was recently reported.

An international team of researchers, led by the UK Centre for Polar Observation and Modelling at the University of Leeds, are the first to map the change in ice speed. The team collated measurements recorded by five different satellites to track changes in the speed of more than 30 glaciers since 1992.


This is a view from the British Antarctic Survey (BAS) Rothera research station, on Alexander Island at the Antarctic Peninsula.

Credit: A. E. Hogg/CPOM

The findings, published today in Geophysical Research Letters, represent the first detailed assessment of changing glacier flow in Western Palmer Land -- the southwestern corner of the Antarctic Peninsula.

The new Leeds led research calls into question a recent study from the University of Bristol that reported 45 cubic kilometres per year increase in ice loss from the sector. The Leeds research found the increase to be three times smaller.

... more about:
»Antarctic »BAS »GLACIERS »satellite »satellites »sea level

Lead author Dr Anna Hogg, from the Leeds' School of Earth and Environment, said: "Dramatic changes have been reported in this part of Antarctica, so we took a closer look at how its glaciers have evolved using 25 years of satellite measurements dating back to the early 1990s."

The researchers found that between 1992 and 2016, the flow of most of the region's glaciers increased by between 20 and 30 centimetres per day, equating to an average 13% speedup across the glaciers of Western Palmer Land as a whole.

These measurements provide the first direct evidence that Western Palmer Land is losing ice due to increased glacier flow -- a process known as dynamical imbalance.

The team also combined their satellite observations with an ice flow model using data assimilation to fill in gaps where the satellites were unable to produce measurements. This allowed the complete pattern of ice flow to be mapped, revealing that the regions glaciers are now pouring an additional 15 cubic kilometres of ice into the oceans each year compared to the 1990s.

The earlier study reported that the region was losing three times this amount of ice, based on measurements of glacier thinning and mass loss determined from other satellite measurements. The Leeds study casts doubt on that interpretation, because the degree of glacier speedup is far too small.

Study co-author Professor Andrew Shepherd, from Leeds' School of Earth and Environment, explained: "Although Western Palmer Land holds a lot of ice -- enough to raise global sea levels by 20 centimetres -- its glaciers can't be responsible for a major contribution to sea level rise, because their speed has barely changed over the past 25 years. It's possible that it has snowed less in this part of Antarctica in recent years -- that would also cause the glaciers to thin and lose mass, but it's a not a signal of dynamical imbalance."

The greatest speedup in flow was observed at glaciers that were grounded at depths more than 300 m below the ocean surface.

Dr Hogg said: "We looked at water temperatures in front of the glaciers which have sped up the most, and we found that they flow through deep bedrock channels into the warmest layer of the ocean. This circumpolar deep water, which is relatively warm and salty compared to other parts of the Southern Ocean, has warmed and shoaled in recent decades, and can melt ice at the base of glaciers which reduces friction and allows them to flow more freely.

With much of Western Palmer Land's ice mass lying well below sea level it is important to monitor how remote areas such as this, are responding to climate change. Satellites are the perfect tool to do this.

Pierre Potin, ESA's Manager of the Copernicus Sentinel-1 Mission which was used in the study, said: "We will continue to use Sentinel-1's all weather, day-night imaging capability to extend the long term climate data record from European satellites."

###

Further information:

Images available for download: goo.gl/Dwg1Ed

Image1 caption: Ice speed in Western Palmer Land on the Antarctic Peninsula measured by the ESA-EU Sentinel-1 satellite mission.
Credit: J. Wuite, ENVEO.

Image 2 caption: View of Western Palmer Land glaciers and George VI Ice Shelf from BAS Twin Otter aeroplane.
Credit: Hogg/CPOM.

Additional images

Caption: View from the British Antarctic Survey (BAS) Rothera research station, on Alexander Island at the Antarctic Peninsula.
Credit: A. E. Hogg/CPOM

Video available for download: goo.gl/5CDNrB

(Animation of the ice speed evolving through the study period)

Caption: Ice flow in Western Palmer Land from 1992 to 2016, from an optimised ice sheet model.
Credit: S. Cornford, CPOM/Univ. Swansea.

Dr Anna Hogg is available for interview.

For interviews and additional information please contact University of Leeds Media Relations Officer Anna Martinez on a.martinez@leeds.ac.uk or +44 (0)113 343 4196 Out of hours number +44 (0)7712389448

Paper reference:

Hogg, A. E., et al. (2017), Increased ice flow in Western Palmer Land linked to ocean melting, Geophys. Res. Lett., 44, (DOI:10.1002/2016GL072110)

University of Bristol study - Wouters at al., [2015] - can be found at: http://science.sciencemag.org/content/348/6237/899

University of Leeds

The University of Leeds is one of the largest higher education institutions in the UK, with more than 31,000 students from 147 different countries, and a member of the Russell Group research-intensive universities.

We are a top 10 university for research and impact power in the UK, according to the 2014 Research Excellence Framework, and positioned as one of the top 100 best universities in the world in the 2015 QS World University Rankings. We are The Times and The Sunday Times University of the Year 2017. http://www.leeds.ac.uk

Centre for Polar Observation and Modelling (CPOM) provides, on behalf of NERC, UK National Capability in observing and modelling the cryosphere. We combine satellite measurements with theoretical and numerical models to explain how Earth's ice, oceans and atmosphere interact, and to predict their behaviour over long periods and large scales.

The CPOM Directorate is based at the University of Leeds, and we have researchers at the Universities of Bristol and Reading and at University College London. CPOM is funded by the Natural Environment Research Council (NERC). We also work closely with the British Antarctic Survey (BAS), National Oceanography Centre (NOC), National Centre for Earth Observation (NCEO) and European Space Agency (ESA). http://www.cpom.org.uk

Media Contact

Anna Martinez
pressoffice@leeds.ac.uk
44-011-334-34196

 @universityleeds

http://www.leeds.ac.uk 

Anna Martinez | EurekAlert!

Further reports about: Antarctic BAS GLACIERS satellite satellites sea level

More articles from Earth Sciences:

nachricht Researchers reveal how microbes cope in phosphorus-deficient tropical soil
23.01.2018 | DOE/Oak Ridge National Laboratory

nachricht Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments
22.01.2018 | Duke University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Researchers reveal how microbes cope in phosphorus-deficient tropical soil

23.01.2018 | Earth Sciences

Opening the cavity floodgates

23.01.2018 | Life Sciences

Siberian scientists suggested a new method for synthesizing a promising magnetic material

23.01.2018 | Materials Sciences

VideoLinks Science & Research
Overview of more VideoLinks >>>