Mapping and characterizing the Kilauea (Hawai'i) lava lake through Sentinel-2 MSI and Landsat-8 OLI observations of December 2020-February 2021

Abstract

On 20 December 2020, a new eruption started at Kilauea volcano (Hawai'i, USA). During the eruption, the lava cascaded into the summit water lake, generating a vigorous steam plume and forming a new lava lake at the base of the crater. In this study, we investigate the lava lake through the Normalized Hot Spot Indices (NHI) algorithm. The latter runs operationally within a Google Earth Engine (GEE) App, using Operational Land Imager (OLI) and Multispectral Instrument (MSI) data, to map volcanic thermal anomalies at global scale. Results show that NHI provided relevant information about the lava lake and relative space-time variations, with a higher accuracy in daylight than nighttime conditions. Moreover, by correcting daytime data for the influence of the solar irradiation, we estimated values of the radiant flux in the range 1-5 GW from hottest pixels. This study opens some challenging scenarios about the hot spot characterization through the App and its automated module running operationally.