Magnetic Signatures of the January 15 2022 Hunga Tonga–Hunga Ha‘apai Volcanic Eruption | CU Experts

On January 15, 2022, at around 04:00 UTC, the submarine volcano Hunga; Tonga-Hunga Ha‘apai explosively erupted. We examine data from ten; 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 minutes period, and ~1nT amplitudes, arrived at; ~04:44 UTC. API’s signals are likely due to ionospheric; sources. 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 minutes; and 5-100+ minutes. 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.

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