Heterogeneous decadal glacier downwasting at the Mt. Everest (Qomolangma) from 2000 to ∼ 2012 based on multi-baseline bistatic SAR interferometry

Remote sensing based geodetic observations can be used as alternatives data to map glacier height changes because the harsh environment complicates in situ observations. In this study, we analysed five pairs of X-band bistatic TerraSAR-X/TanDEM-X images from 2011 and 2014 for Mt. Everest (Qomolangma). Glacier height changes were derived using the D-InSAR method respect to SRTM DEM of 2000. An iterative D-InSAR method using multi -baseline bistatic SAR interferograms was employed, which increased reliability and accuracy of glacier height changing observations. From 2000 to similar to 2012, the geodetic glacier mass balance for the Mt. Everest and the surrounding region was - 0.38 +/- 0.04 m w.e. a(-1). The spatial pattern of the glacier mass loss was heterogeneous. The regional heterogeneity may possibly reflect debris-covering rates, terminating type, temperature rising rates and glacier flow rates. Comparison to long-period geodetic glacier mass balance data provided by previous studies since 1970 revealed that our results showed more rapid increases in the glacier mass loss rates after 2000 in the area around Khumbu Glacier in the southern slope of the Mt. Everest, whereas glacier mass loss rates kept stable in the Rongbuk Catchment at its northern slope.