Abstract
Most of Earth’s volcanic eruptions occur underwater, and these submarine
eruptions can significantly impact large-scale earth systems. In this
study, we develop a new semi-automated analysis framework to detect
submarine eruptions through the supervised classification of satellite
images on Google Earth Engine (GEE). We present a case study from the
Rabaul caldera region in Papua New Guinea and find a large number of new
unreported pumice rafts (in ~16% of images from
2017–present). After analysis of the spatial pattern of raft sightings
and ancillary observations, we interpret that these rafts are not the
result of a new eruption. Instead, we posit that the observed rafts
represent remobilization of pumice clasts from previous historical
eruptions. This novel process of raft remobilization may be common at
near-shore/partially submarine caldera systems (e.g., Rabaul, Krakatau)
and has significant implications for new submarine eruption detection,
volcanic stratigraphy, and biological dispersal by rafts.