The Seismo‐Acoustics of Submarine Volcanic Eruptions

Abstract

Many of the world’s volcanoes are hidden beneath the ocean’s surface where eruptions are difficult to observe. However, seismo‐acoustic signals produced by these eruptions provide a useful means of identifying active submarine volcanism. A literature survey revealed reports of 119 seismo‐acoustically recorded submarine eruptions since 1939. Submarine eruptions have been recorded in all major tectonic settings, with a range of geochemistries, and at a variety of water depths, but the reports are dominated by eruptions in the Pacific and at only a few locations. Many of the reports offer little detail, with over half of the observations made from distances >500 km, and only about half were confirmed as eruptions by non‐seismo‐acoustic evidence. The reported seismo‐acoustic signals cover a wide variety of processes, including earthquakes, explosions, various types of tremor, signals related to lava extrusion, and landslides. Recorded signals can sometimes be difficult to classify or confidently associate with an eruption, although there has been progress in this regard. Real‐time monitoring of submarine eruptions has been on‐going for several decades on regional and global scales with growing interest and effort in local networks. Real‐time networks are complemented by short‐term instrument deployments that often give more detailed insights into the dynamics and processes of submarine eruptions. Thorough seismo‐acoustic monitoring and study has increased our understanding of submarine eruptions, especially of deep‐sea volcanoes and spreading centers. Despite this, there are still many outstanding questions that need to be addressed for submarine volcanoes to be as well understood and monitored as their terrestrial counterparts.

Natural and Anthropogenic Sources of Seismic, Hydroacoustic, and Infrasonic Waves: Waveforms and Spectral Characteristics (and Their Applicability for Sensor Calibration)

“…Detailed studies on anthropogenic sources are found in Bohnenstiehl et al ( 2012 ) and Wiggins et al ( 2016 ). Marine volcanism is examined in detail in Tepp and Dziak ( 2021 ) and Talandier et al ( 2006 ) provide an overview of signals associated with the cryosphere. For a general overview of noise in the ocean, see Miksis-Olds and Nichols ( 2016 ).…”

“…The first hydroacoustic observation of underwater volcanism was made by Dietz and Sheehy ( 1954 ) at a distance of about 400 km. Since then, hydroacoustic methods have been used to record seismic activity associated with submarine volcanic eruptions throughout all ocean basins (Dziak and Fox 2002 ; Tepp and Dziak 2021 ).…”

“…Summaries about submarine volcanism investigated using hydroacoustic recordings are given in Norris and Johnson ( 1967 ) and Tepp and Dziak ( 2021 ). Fox et al ( 2001 ) use autonomous hydrophone moorings for long-term monitoring of seismic activity on the East Pacific Rise, observing tremors and earthquakes associated with volcanic activity.…”

“…Metz et al 2018 ). An overview of the relevant processes can be found in the review by Tepp and Dziak ( 2021 ). Because of the many mechanisms involved, a variety of seismoacoustic signals with different characteristics are produced, some of which are difficult to distinguish from other events.…”

Pumice Raft Detection Using Machine-Learning on Multispectral Satellite Imagery

“…In addition, unlike subaerial volcanoes, precursory gas emissions or thermal anomalies are much more difficult to detect beneath the water surface. Although multiple new approaches have been proposed to improve submarine volcanism detection, including hydro-acoustics [e.g., (Heaney et al, 2013;Tepp et al, 2019)], seismic and ground deformation with ocean bottom seismometers (Wilcock et al, 2016;Matsumoto et al, 2019;Cesca et al, 2020;Tepp and Dziak, 2021), and ocean thermal anomalies (Baker et al, 1989;Mittal and Delbridge, 2019), challenges remain due to limited global instrumental coverage. In this study, we describe another dataset-satellite imagery-that can be used to efficiently detect and characterize products of submarine volcanism.…”