Feeds

West Antarctic ice loss overestimated by NASA sats

Incorrect allowance made for trampoline-like bedrock

Boost IT visibility and business value

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. ®

Gartner critical capabilities for enterprise endpoint backup

More from The Register

next story
LOHAN packs bags for SPACEPORT AMERICA!
Spanish launch goes titsup, we're off to the US of A
Gigantic toothless 'DRAGONS' dominated Earth's early skies
Gummy pterosaurs outlived toothy competitors
'Leccy racer whacks petrols in Oz race
ELMOFO rakes in two wins in sanctioned race
TRANSMUTATION claims US LENR company
Ten points of stuff out of a five pound bag
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
BAT-GOBBLING urban SPIDER QUEENS swell to ENORMOUS SIZE
But they'd lose a deathmatch against the coming Humvee-sized, armoured Arctic ones
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
Boffins build CYBORG-MOTHRA but not for evil: For search & rescue
This tiny bio-bot will chew through your clothes then save your life
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
BYOD's dark side: Data protection
An endpoint data protection solution that adds value to the user and the organization so it can protect itself from data loss as well as leverage corporate data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
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?