A few weeks ago I explained on WUWT that the UT interpretation of GRACE gravity anomaly data was flawed, due to calibration problems caused by isostasy.
September 2, 2010 by M & C
The melting of the ice sheets of Greenland and West Antarctica is about twice as slow as previously thought. The study, conducted by TU Delft, SRON and the Jet Propulsion Laboratory. The scientists published their findings in the September issue of Nature Geoscience.
The melting of ice sheets since 2002 is mapped with measurements of the two GRACE satellites. These detect from space small changes in the gravitational field of the earth. These changes are related to the exact distribution of mass on Earth, including ice and water. As ice melts and sea, is this influence in the gravity field.
Based on this principle were previous estimates for the Greenland ice sheet at 230 gigatons of ice that melts each year (that’s 230,000 billion pounds). This results then in an average global sea level rise of about 0.75 mm per year. For West Antarctica was the estimated 132 gigatons each year.
With these results, it now appears, however, not corrected for glacial Isostatic adjustment, the phenomenon that the earth’s crust continues to soar due to the melting of large ice sheets of the last Ice Age, about 20,000 years ago. These movements of the crust should you take in the calculations for these vertical motions change the mass distribution of the earth and so they also affect the gravity field.
h/t to WUWT reader “seven”