Tracking glacier surge evolution using interferometric SAR coherence—examples from Svalbard

We present a practically simple methodology for tracking glacier surge onset and evolution using interferometric synthetic aperture radar (InSAR) coherence. Detecting surges early and monitoring their build-up is interesting for a multitude of scientific and safety-related aspects. We show that InSAR coherence maps allow the detection of surge-related instability on Svalbard many years before being detectable by, for instance, feature tracking or crevasse detection. Furthermore, we present derived data for two types of surges; down- and up-glacier propagating, with interestingly consistent surge propagation and post-surge relaxation rates. The method works well on Svalbard glaciers, and the data and core principle suggest a global applicability.