Feeds

West Antarctic ice loss overestimated by NASA sats

Incorrect allowance made for trampoline-like bedrock

Beginner's guide to SSL certificates

Scientists using a network of ground sensors emplaced in Antarctica say that NASA satellites have overestimated the amount of ice that is melting and running off into the ocean from the polar continent.

The new results come from the West Antarctic GPS Network (WAGN), which uses 18 locator stations "bolted to bedrock outcrops" in the Western antarctic to discover "ground truth" regarding the phenomenon of "postglacial rebound", where the bedrock lifts as the mile-thick ice sheet atop it diminishes.

Postglacial rebound is important, as NASA's Gravity Recovery and Climate Experiment (GRACE) satellites estimate ice loss by measuring regional gravitational forces as they fly overhead. Both ice loss and bedrock rebound contribute to GRACE grav-scan readings, and according to the WAGN measurements, rebound figures used to estimate ice loss have now been shown to be wrong.

"The take home message is that Antarctica is contributing to rising sea levels. It is the rate that is unclear," says Ian Dalziel, lead investigator for WAGN.

The WAGN boffins say they are sure that recent figures for ice loss calculated from GRACE readings have been overestimated, but they are not yet sure by how much. However, they say that there is no dispute about the fact that ice is disappearing from the antarctic sheet - this process has been underway for 20,000 years, since the thickness peaked during the last "glacial maximum".

"The published results are very important because they provide precise, ground-truth GPS observations of the actual rebound of the continent," said Vladimir Papitashvili of the Antarctic Earth Sciences Program at the National Science Foundation, which supported the research.

The results are given in the paper Geodetic Measurements of Vertical Crustal Velocity in West Antarctica and the Implications for Ice Mass Balance, published here in the journal Geochemistry, Geophysics, Geosystems (subscriber link). There's also some layman-level exposition from Texas uni here. ®

Remote control for virtualized desktops

More from The Register

next story
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
I'll be back (and forward): Hollywood's time travel tribulations
Quick, call the Time Cops to sort out this paradox!
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
prev story

Whitepapers

Driving business with continuous operational intelligence
Introducing an innovative approach offered by ExtraHop for producing continuous operational intelligence.
Why CIOs should rethink endpoint data protection in the age of mobility
Assessing trends in data protection, specifically with respect to mobile devices, BYOD, and remote employees.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Reducing the cost and complexity of web vulnerability management
How using vulnerability assessments to identify exploitable weaknesses and take corrective action can reduce the risk of hackers finding your site and attacking it.