Lava flow delineation by using Sentinel2 and Landsat8 images: Kīlauea -Leilani 2018, Italy Etna 2021, La Palma Cumbre Vieja 2021 cases

Abstract

<p>Kīlauea is a broad shield volcano built against the southeastern slope of Mauna Loa. The summit presently has a caldera that is roughly 4km by 3.2km wide, and walls of between 0 m and 120 m high. In the 2018, late April an eruption interesting both the summit crater and the lower East Rift Zone (LERZ) occurred. A quasi real time estimation of the evolution of radiant lava flow extension starting from May 2018 for Kīlauea –Leilani eruption using satellite image data has been produced. The active lava flow evolution is obtained by using Copernicus Sentinel2 (S2) and U.S. Geological Survey (USGS)-Landsat8 (L8) polar satellites acquiring medium/high spatial resolution images (20mx20m and 30mx30m respectively) in the visible-Short Wave Infra Red- Thermal Infra Red (VIS-SWIR-TIR) spectral range. Remote sensing has become an important information source for environmental monitoring and in particular during eruption assisting volcanologists for lava flow mapping. In the contest of Leilani 2018 eruption the combination of L8 and S2 data has offered the unique opportunity to observe the LERZ area, nominally, every 3,6 days (30 images in 97 days) at medium (<30m) spatial resolution. Because of the Kīlauea eruption extension and duration, a multi sensor approach has been used in order to improve the timing of the information derived by high spatial resolution remote sensed data merging two missions with different revisit time. To process the data acquired we have adopted a modified version of Murphy algorithm (2016) which reduces, in the case of very high thermal event, the misinterpretation of hottest pixels. It is fundamental to remind that the method used may recognize only the radiant portion of the lava flow sensed during a satellite passage that lasts a few time with respect to the lava flow emplacement. Therefore, it can be used for mapping the hottest area and not the whole lava flows produced over time (Musacchio et al., 2020).</p> <p>Beside the Kīlauea -Leilani 2018 event, results for Italy Etna 2021 and La Palma Cumbre Vieja 2021 are presented also including ASI-PRISMA datasets.</p> <p> </p> <p>Murphy, S. W., de Souza Filho, C. R., Wright, R., Sabatino, G., & Pabon, R. C. (2016). HOTMAP: Global hot target detection at moderate spatial resolution. Remote sensing of environment, 177, 78-88.</p> <p>Musacchio, M., Silvestri, M., Rabuffi, F., Buongiorno, M. F., & Falcone, S. (2020). Kīlauea–Leilani 2018 lava flow delineation using Sentinel2 and Landsat8 images. Geological Society, London, Special Publications, 519(1), SP519-2020.</p>