Past and present-day ice mass variation on Svalbard revealed by superconducting gravimeter and GPS measurements

Abstract

[1] We use Superconducting Gravimeter (SG) and Global Positioning System (GPS) measurements from Ny-Alesund, Svalbard, to infer changes in ice mass loss between September 1999 and September 2010. We find that during this period, the gravity rate and vertical crustal velocities are changing with time, adding to evidence about varying rates of ice mass loss. The gravity rate varies through 10 years of observation; −0.23 μGal/yr in 2000–2002, −3.22 μGal/yr in 2002–2005 and −1.10 μGal/yr in 2005–2010. The gravity changes agree well with the observed uplift rates measured by GPS, which are 4.4, 11.3 and 7.4 mm/yr, over the same periods. In addition, we generate model predictions which account for past and present-day ice mass variation. We find that the models under predict both the observed uplift rates and gravity changes.