Photon Phright-day: Ghost Islands

From the creator

Remote, recently formed (via volcanic eruptions) oceanic islands in the deep ocean can be studied by satellite lidar altimetry as ICESat2 has been doing, but especially with the satellite lidar bathymetry of the shallows where even ship-based sonars cannot go due to shallow, rough waters. At Hunga Tonga Hunga Ha’apai (HTHH), the interior crater lake probably represents a vent complex for the tuff cone volcano that erupted over about one month in late 2014 into January 2015, forming the first “surtseyan” island that has survived for more than one year in more than 50 years. This crater lake can now be explored via ICESat-2 satellite lidar bathymetry using precision-targeted transections that can show submarine topography to depths greater than 10 meters. Our raft-based low-resolution sonar sounder depth readings from October 2019 SEA/NASA field expedition to HTHH suggest max depth are 12-15 meters with 1-2 meter vertical errors on these values. The high precision ICESat2 lidar bathymetry measured depths of greater than 10 meters on the inner crater walls and over time could develop a map of bathymetric points to fully characterize the crater without requiring costly and logistically complex field operations at the remote island. ICESat2’s agility in measuring uniquely dynamic and sometimes short-lived phenomena is unique and showcases its contribution to Earth sciences priorities in this era of climate change and sea-level rise. More on ICESat-2: https://nasa.gov/icesat

Published 2021-10-29 · Watch on YouTube ↗
Availability and playback restrictions are controlled by the original channel.