Feeds

West Antarctic ice loss overestimated by NASA sats

Incorrect allowance made for trampoline-like bedrock

A new approach to endpoint data protection

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. ®

The Essential Guide to IT Transformation

More from The Register

next story
Just TWO climate committee MPs contradict IPCC: The two with SCIENCE degrees
'Greenhouse effect is real, but as for the rest of it ...'
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
Brit amateur payload set to complete full circle around PLANET EARTH
Ultralight solar radio tracker in glorious 25,000km almost-space odyssey
Boffins spot weirder quantum capers as neutrons take the high road, spin takes the low
Cheshire cat effect see neutrons and their properties walk different paths
NASA Mars rover FINALLY equals 1973 Soviet benchmark
Yet to surpass ancient Greek one, however
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
prev story

Whitepapers

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.
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.
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.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
A new approach to endpoint data protection
What is the best way to ensure comprehensive visibility, management, and control of information on both company-owned and employee-owned devices?