Recent Glacier Dynamics in the Northern Novaya Zemlya Observed by Multiple Geodetic Techniques

In Novaya Zemlya (NVZ), melting marine-terminating glaciers have been identified to be the most significant contributor to the ice loss. However, the influence of influx on mass loss has not been discussed in previous studies. In this study, we present multiple geodetic observations of four glaciers along the Barents Sea coast to determine the influence of glacier outflow on net mass change by considering the mass gain from snowfall. We obtained the average ice loss rate of -1.04 +/- 0.25 Gt year(-1) during the period of 2003-2014 from the gravity recovery and climate experiment (GRACE) data. We discovered an interannual increase of 4.30 +/- 0.97 Gt year(-1) in 2007-2010 which had not been presented. In addition, we also observed two other interannual variations in the form of negative mass trends from GRACE during the periods of 2004-2007 and 2010-2014. A speckle-matching technique was applied on pairs of synthetic aperture radar data to fill the gap of velocity estimations for the period of 2007-2010 which were not reported in previous studies. The mass increase in 2007-2010 can be explained by the increase in influx while the change in outflow was negligible. In addition, we extended similar analysis to the periods of 2002-2007 and 2010-2014, and identified the contribution of outflow and influx to the mass change in NVZ. In particular, the mass losses in the periods of 2004-2007 and 2010-2013 in NVZ were related to the significant increase of outflow while positive influx anomalies were observed.