Measuring Landslides and Volcanic Eruptions with ArcticDEM

The ArcticDEM project (www.arcticdem.org) has recently released a large collection of 2-meter resolution time-variable Digital Elevation Models (DEMs) covering all land areas above 60 degrees North and all of Greenland, Alaska, and Kamchatka. The accuracy of these data, created from stereophotogrammetry applied to commercial satellite imagery, is comparable to that obtained from airborne surveys (order of decimeters with ground control), and large areas have 10 or more repeat measurements spanning over a decade. Here we develop time series analysis algorithms to efficiently identify and quantify land surface change from time-dependent DEMs. We present the production of high resolution (2 m) mass redistribution maps for the 17 October 2015 landslide at Tyndall Glacier, Alaska and the 17 June 2017 Karrat Fjord tsunamigenic landslide in the northwestern region of Greenland. We also present the co-eruptive deposit thickness map and post-eruption erosion rate map corresponding to the 2008 eruption of Okmok volcano . The generated elevation change rate demonstrates the first-of-its-kind measurements of the post-eruptive remobilization of sediment, revealing the erosion rate up to - 15 m/year along flanks of the new cone (Ahmanilix) and the redeposition rate of about 1 m/year or 5 m/year at the base or the center of Ahmanilix. This study demonstrates the potentially transformative capability of ArcticDEM for measuring topographic change over the highly dynamic Arctic land surface.