US: According to a new study, NASA’s two earth observation satellites – ICESat and GRACE – have helped in revealing the role of glaciers in global sea level rise. The new research found glaciers outside of the Greenland and Antarctic ice sheets, repositories of 1% of all land ice, lost an average of 571 trillion pounds (259 trillion kilograms) of mass every year during the six-year study period, making the oceans rise 0.03 inches (0.7 mm) per year. This is equal to about 30% of the total observed global sea level rise during the same period and matches the combined contribution to sea level from the Greenland and Antarctica ice sheets.
The study compares traditional ground measurements to satellite data from NASA”s ICESat and GRACE missions to estimate ice loss for glaciers in all regions of the planet. The study period spans 2003 to 2009, the years when the two missions overlapped.
“For the first time, we have been able to very precisely constrain how much these glaciers as a whole are contributing to sea level rise,” said Alex Gardner, Earth scientist at Clark University in Worcester, Mass., and lead author of the study. “These smaller ice bodies are currently losing about as much mass as the ice sheets.”