Scripps-led study finds melting rates 25 times higher than expected
A new Scripps Institution of Oceanography at UC San Diego-led study measured a melt rate that is 25 times higher than expected on one part of the Ross Ice Shelf. The study suggests that high, localized melt rates such as this one on Antarctica's largest and most stable ice shelf are normal and keep Antarctica's ice sheets in balance.
The Ross Ice Shelf, a floating body of land ice the size of France jutting out from the Antarctic mainland, continuously melts and grows in response to changes to both the ice sheet feeding it and the warmer Southern Ocean waters beneath it.
For six weeks the researchers collected radar data to map changes in ice shelf thickness to understand the processes that contribute to melting at its base. The findings revealed dramatic changes in melt rate within less than a mile.
The highest melting rates of more than 20 meters (66 feet) per year are thought to contribute to the rapid formation of channels at the base of the ice shelf, which can result from fresh water flowing out from lakes under the West Antarctica ice sheet. Shifts in subglacial drainage patterns change the location of these basal channels, which could impact the ice shelf's stability by unevenly distributing the melting at the base.
"The highest melt rates are all clustered at the start of a developing ice shelf channel," said Scripps alumnus Oliver Marsh, a postdoctoral researcher at the University of Canterbury and lead author of the study. "The location of the melting strengthens the idea that freshwater from the local subglacial drainage system is responsible for the evolving ice shelf features."
The study, published in the American Geophysical Union's Geophysical Research Letters, is the first to document fine-scale changes taking place on the ice shelf that help maintain its natural balance with the surrounding ocean waters.
"It's just as important to study the places that aren't changing as the ones that are," said Scripps glaciologist Helen Amanda Fricker, a co-author of the study. "We need to understand what is causing the melting in order to predict how these places may change in the future."
Melting of ice shelves does not directly contribute to sea-level rise, but instead they hold back water frozen in the larger ice sheet that will cause sea levels to rise. The study helps researchers understand the oceanographic processes necessary to better predict future sea-level rise from the melting of ice sheets due to climate change.
"Below the Ross Sea is one of the most remote parts of the ocean floor, and is largely unmapped," said Matt Siegfried, Scripps postdoctoral researcher and a co-author of the study. "This research is helping us better understand the interactions between the ice sheet and the ocean in this remote region on Earth."
According to the researchers, more sustained, long-term measurements are necessary to determine the exact cause of the high melt rate and how it changes over seasonal or annual timescales.
The study, part of the National Science Foundation-funded Whillans Ice Stream Subglacial Access Research Drilling project (WISSARD), was supported by UC San Diego's John Dove Isaacs Chair in Natural Philosophy awarded to Fricker.
Scripps Institution of Oceanography: scripps.ucsd.edu
Scripps News: scrippsnews.ucsd.edu
About Scripps Institution of Oceanography
Scripps Institution of Oceanography at the University of California, San Diego, is one of the oldest, largest, and most important centers for global science research and education in the world. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical, and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today on every continent and in every ocean. The institution has a staff of more than 1,400 and annual expenditures of approximately $195 million from federal, state, and private sources. Scripps operates oceanographic research vessels recognized worldwide for their outstanding capabilities. Equipped with innovative instruments for ocean exploration, these ships constitute mobile laboratories and observatories that serve students and researchers from institutions throughout the world. Birch Aquarium at Scripps serves as the interpretive center of the institution and showcases Scripps research and a diverse array of marine life through exhibits and programming for more than 430,000 visitors each year. Learn more at scripps.ucsd.edu and follow us at: Facebook | Twitter | Instagram.
About UC San Diego
The University of California, San Diego is a student-centered, research-focused, service-oriented public institution that provides opportunity for all. Recognized as one of the top 15 research universities worldwide and born of a culture of collaboration, UC San Diego sparks discoveries that advance society, drive economic growth and positively impact the world. Our students, who learn from Nobel laureates, MacArthur Fellows and National Academy members, are committed to public service. For the sixth consecutive year, UC San Diego has been ranked first in the nation based on research, civic engagement and social mobility. We are one campus with multiple pillars of excellence, a top ten public university that is transforming lives, shaping new disciplines and advancing the frontiers of knowledge. Learn more at http://www.
Mario Aguilera | EurekAlert!
Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University
Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy