Joint multi-sensor infrared satellite and laboratory measurements for lava discharge rate estimation of 2018 Kilauea Volcano, Hawai'i eruption

Abstract

Kilauea Volcano, Hawai'i, is one of the world's most active volcanoes. From 1983 to 2018 the magmatic system was in near continuous eruptions. This eruption ended on 30 April 2018 when the deflation of Kilauea caldera began and seismic data showed a dike intrusion from the Middle East Rift Zone of Kilauea Volcano downrift towards the Lower East Rift Zone (LERZ). On 3 May 2018, the first of final 24 eruptive fissures opened at the LERZ. This was the beginning of the largest effusive event of the last two hundred years at the LERZ. Here, we present a joint analysis of multi-sensor infrared (IR) Visible Infrared Imaging Radiometer Suite (VIIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Earth observation data together with laboratory viscosity measurements to estimate the Time-Averaged Discharge Rate (TADR) and lava eruption volume of this large eruption event at the LERZ. After an TADR estimation performed independently for each sensor data in order to cross-check the results against each other, a joint timeseries of the VIIRS and MODIS TADR estimates was created to obtain more frequent measurements. This joint analysis of VIIRS and MODIS data resulted in an erupted lava volume of 0.924 ± 0.462 km³. Independent measurements based on airborne LIDAR and Synthetic Aperture Radar Interferometry (InSAR) topography changes are within the range of the IR data-based estimates of the erupted lava volume. Based on major element compositions of the eruptive products, the 2018 LERZ eruption could be differentiated into four main phases, which showed according to the VIIRS and MODIS-based TADR estimation a strong increase of the Mean Output Rate (MOR) during the evolution of the eruption from early/late Phase I, over Phase II until Phase III. This strong increase of the MOR during the different phases of the 2018 LERZ eruption agrees well with the evolution of the lava from low-temperature, highly differentiated lava flows in the beginning to high-temperature mafic more fluid lava from Phase II onwards, as observed in the field by the USGS.