Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA's IceBridge Mission Contributes to New Map of Antarctica

05.06.2013
A new dataset called Bedmap2 gives a clearer picture of Antarctica from the ice surface down to the bedrock below.

Bedmap2 is a significant improvement on the previous collection of Antarctic data—known as Bedmap—that was produced more than 10 years ago. The product was a result of work led by the British Antarctic Survey, where researchers compiled decades worth of geophysical measurements, such as surface elevation measurements from NASA's Ice, Cloud and Land Elevation Satellite, known as ICESat, and ice thickness data collected by Operation IceBridge.


These images depict the differences between Antarctica's ice sheet with its underlying topography. Click and drag the white bar to compare the images. (Vertical scale has been magnified by a factor of 17 to make terrain features such as mountains and valleys more visible.) The topography map, called Bedmap2, was compiled by the British Antarctic Survey and incorporates millions of new measurements, including substantial data sets from NASA's ICESat satellite and an airborne mission called Operation IceBridge.

Credit: NASA's Goddard Space Flight Center

With effects ranging from influencing ocean currents to raising sea level, Antarctica plays a large role in the global climate system. Researchers are using a variety of methods to understand how Antarctica will react to a changing climate, but limited information on ice thickness and what lies beneath the ice makes this work challenging. Now, thanks to work led by the British Antarctic Survey published recently in the journal The Cryosphere, scientists will have a new detailed map of the frozen continent.

A Better Map

Bedmap2, like the original Bedmap, is a collection of three datasets—surface elevation, ice thickness and bedrock topography. Over the past decade there have been many Antarctic surveys, which vastly increased the amount of available data. Researchers used data from satellites, aircraft and surface-based surveys to build a data product with higher resolution, greater coverage and improved precision. Both Bedmap and Bedmap2 are laid out as grids covering the entire continent, but with a tighter grid spacing, Bedmap2 includes many surface and sub-ice features too small to be seen in the previous dataset. The millions of additional data points in Bedmap2 also cover a larger percentage of Antarctica. Additionally, the extensive use of GPS data in more recent surveys improves the precision of the new dataset. Improvements in resolution, coverage and precision will lead to more accurate calculations of ice volume and potential contribution to sea level rise.

Total ice volume and sea level contribution remain similar to calculations using the original Bedmap, but Antarctica's average bedrock depth, deepest point and ice thickness estimates have all increased. Peter Fretwell, BAS scientist and lead author, said the new dataset increases our knowledge of the sub-glacial environment and will be help future research on the Antarctic ice sheet. "It will be an important resource for the next generation of ice sheet modelers, physical oceanographers and structural geologists," said Fretwell.

A Better Model

Ice sheet modeling is an area that will likely make heavy use of Bedmap2 data. Ice sheets are thick, dome-shaped formations of ice that cover large areas of land. There are two major ice sheets on Earth, one covering Greenland and one over Antarctica. Ice sheets are formed as snow accumulates and is compacted into ice over many years. "Ice sheets grow because of snow, and like honey poured on a plate, spread outward and thin due to their own weight," said Sophie Nowicki, an ice sheet scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

Ice sheet researchers use computer models to simulate how ice sheets will respond to changes in ocean and air temperatures. An advantage of these simulations is that they allow testing of many different climate scenarios, but the models are limited by how accurate the data on ice volume and sub-ice terrain are. "In order to accurately simulate the dynamic response of ice sheets to changing environmental conditions, such as temperature and snow accumulation, we need to know the shape and structure of the bedrock below the ice sheets in great detail," said Michael Studinger, IceBridge project scientist at NASA Goddard.

Knowing what the bedrock looks like is important for ice sheet modeling because features in the bed control the ice's shape and affect how it moves. Ice will flow faster on a downhill slope, while an uphill slope or bumpy terrain can slow an ice sheet down or even hold it in place temporarily. "The shape of the bed is the most important unknown, and affect how ice can flow," said Nowicki. "You can influence how honey spreads on your plate, by simply varying how you hold your plate." The vastly improved bedrock data included in Bedmap2 should provide the level of detail needed for models to be realistic.

Disparate Data

Creating such a detailed map required researchers to collect and analyze large sums of data from a variety of sources. NASA contributed significant amounts of data on surface elevation, ice shelf limits and ice thickness. For example, measurements from three Operation IceBridge airborne campaigns make up about 12 percent of the 25 million ice thickness data points gathered by more than 200 airborne campaigns over the past 50 years.

IceBridge uses an ice-penetrating radar instrument known as the Multichannel Coherent Radar Depth Sounder to gather data on ice thickness and subglacial topography. MCoRDS, operated by the Center for the Remote Sensing of Ice Sheets at the University of Kansas, sends radar signals down through the ice and records the angle and timing of returning waves to image the ice surface, internal layering and the bedrock below.

Researchers also used a large amount of ICESat data to build the surface elevation grid in hard-to-measure areas. Satellite radar altimetry, which makes up a large portion of Bedmap2, works best in flat areas. Mountainous and steeply sloping areas call for other methods, and data from ICESat's laser altimeter helped researchers build an accurate map in these regions. In addition, the Bedmap2 team used IceBridge altimetry data to verify the accuracy of the combined surface datasets.

IceBridge data also played a big role by providing data on parts of Antarctica where there have been few to no measurements before. One such area is the Recovery Ice Stream, which IceBridge essentially put on the map with data from its 2011 Antarctic campaign. Both NASA and the U.S. National Science Foundation have invested a great deal of time and money in radars like MCoRDS and airborne campaigns like IceBridge over the years.

NASA's contributions go beyond merely collecting this data. By making its data freely available to researchers, NASA is leading a positive trend with researchers. "We hope that other partners will also go down this road," said Fretwell. Collecting radar sounding data over Antarctica is an expensive effort, which has led some researchers to be understandably protective. This could change, however, as more researchers make use of freely available data.

"More and more people in the research community realize the tremendous value of making data freely available," said Studinger.

For more information on NASA's Operation Ice Bridge, visit:
http://www.nasa.gov/icebridge
George Hale
NASA's Goddard Space Flight Center, Greenbelt, Md.

George Hale | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/topics/earth/features/antarctic-map.html

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Individualized fiber components for the world market

23.06.2017 | Physics and Astronomy

How brains surrender to sleep

23.06.2017 | Life Sciences

Can we see monkeys from space? Emerging technologies to map biodiversity

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>