Topographic Changes During the 2018 Kīlauea Eruption From Single‐Pass Airborne InSAR

The 2018 eruption of Kīlauea volcano, Hawai‘i, was its most effusive in over 200 years. We apply the airborne Glacier and Ice Surface Topography Interferometer (GLISTIN‐A) interferometric synthetic aperture radar (InSAR) instrument to measure topographic change associated with the eruption. The GLISTIN‐A radar flew in response to the eruption, acquiring observations of Kīlauea on 7 days between 18 May and 15 September 2018. Topography differences were computed relative to GLISTIN‐A observations in 2017. Bare‐Earth topography and offshore bathymetry were used to correct for vegetation and creation of new coastal land within the lower East Rift Zone (LERZ) lava flow field. We estimate that the LERZ subaerial flows total bulk volume is 0.593 ± 0.011 km3 and that the summit collapse volume is −0.836 ± 0.002 km3. Within the temporal sampling and uncertainty from submarine flow volumes, we find that both the LERZ and caldera volume changes were approximately linear. Plain Language Summary Large volcanic eruptions can produce large changes in topography, whether due to loss of topography caused by explosive eruptions or collapse of a caldera due to magma withdrawal or topography gain from lava flows or debris deposition. The 2018 eruption of Kīlauea volcano, Hawai‘i, was its most effusive in over 200 years. We apply the airborne Glacier and Ice Surface Topography Interferometer interferometric synthetic aperture radar instrument to measure topographic change associated with the eruption. The Glacier and Ice Surface Topography Interferometer radar flew in response to the eruption, acquiring observations of Kīlauea on 7 days between 18 May and 15 September 2018. We estimate that the LERZ subaerial flows total bulk volume is 0.593 ± 0.011 km3 and that the summit collapse volume is −0.836 ± 0.002 km3. Within the temporal sampling and uncertainty from submarine flow volumes, we find that both the LERZ and caldera volume changes were approximately linear.