Lava discharge rates determined from TanDEM-X imagery from Kīlauea Volcano, Hawai´i

The ability to measure the discharge rate of lava during a volcanic eruption is of fundamental importance to tracking eruptive activity and associated hazards. While there are many means of measuring the volume rate of extruded lava, differencing of digital elevation models (DEMs) has provided exceptional results at volcanoes around the world. Topographic data derived from TanDEM-X synthetic aperture radar imagery span lava emplacement at Ki̅lauea Volcano, Hawai´i, in 2011-2013. Differences between sequential TanDEM-X-derived DEMs reveal the four-dimensional evolution of Ki̅lauea´s lava flow field, which increased in thickness by up to 30 meters during that span. The volume and area of the lava flow field at each time step can be used to determine the average discharge rate of lava. During 2012, when all lava was erupted on land, the discharge rate was about half the volcano´s long-term average. No other measure of lava effusion was available at Ki̅lauea in 2012, demonstrating the importance of TanDEM-X DEM differences for volcano monitoring and hazards assessment.