Magnetic Signatures of the 15 January 2022 Hunga Tonga-Hunga Ha'apai Volcanic Eruption

On 15 January 2022, at around 04:00 UTC, the submarine volcano Hunga Tonga-Hunga Ha'apai explosively erupted. We examine data from 10 Pacific Ocean geomagnetic observatories and process the data using both high pass filters and cross-wavelet analyses to enable evaluating the time-frequency characteristics of the magnetic signals across the Pacific region. At the Western Samoa observatory (API), magnetic signals of 3-8 min period, and visible in both vertical and horizontal fields, arrived at similar to 04:44 UTC. The observatories at Chichijima Island (CBI) and Easter Island (IPM) both had local magnetic signatures concurrent with the eruption's water wave arrival and period ranges from, respectively, 13-93 and 5-100+ min. At CBI and IPM, the magnetic signal may be due to both the eruption's tsunami water wave and atmospheric/ionospheric sources. Our results suggest that the magnetic signatures from the eruption are identifiable and may be further separated in future studies.