The application of high resolution EarthDEM and ArcticDEM digital elevation models to detect and quantify volcanic activity: successes and challenges

Quantifying topographic changes of volcano surfaces provides important information about volcanic deposits and mass wasting processes, which has specific implications for forecasting volcanic hazards. EarthDEM and ArcticDEM are Digital Elevation Models (DEMs) derived from commercial Maxar stereo-optical satellite data. These DEMs allow for potential global volcanic monitoring of topography at a high resolution (2 m) but have not been used routinely to study volcanoes up to now. Here we show how these DEMs may be used to detect and quantify volcanic activity and describe the successes and challenges of using these data. We studied 9 volcanoes, in locations ranging from equatorial to polar in Indonesia, Galápagos (Ecuador), Kamchatka (Russia) and the Aleutian arc (USA). These volcanoes experienced a wide range of volcanic eruptions that generated different eruptive deposits (lava flows, lava domes, pyroclastic density currents), mass-wasting (lahars and debris avalanches), and erosional features (collapse scars, channels, etc.). The 2 m DEM resolution allowed us to detect topographic changes associated with different volcanic activity, often in difficult environmental conditions (e.g. snow cover). Cloudless, artifact-free DEMs are most successful in quantifying height and volumes changes, including for small and narrow regions (e.g. channels). These DEMs perform well in detecting height changes≥0.5–2 m, which is the range of vertical data errors. Our results demonstrate the value of EarthDEM and ArcticDEM in detecting and quantifying unique signals related to volcanic activity in different environments. Acquisition of high resolution DEMs on a more frequent basis could significantly improve our ability to document time-dependent topographic changes at volcanoes worldwide.