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Magnetic Signatures of the January 15 2022 Hunga Tonga–Hunga Ha‘apai Volcanic Eruption
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  • Neesha Schnepf,
  • Takuto Minami,
  • Hiroaki Toh,
  • Manoj Nair
Neesha Schnepf
Laboratory for Atmospheric & Space Physics

Corresponding Author:[email protected]

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Takuto Minami
Kobe University
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Hiroaki Toh
Kyoto University
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Manoj Nair
Cooperative Institute for Research in Environmental Sciences
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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.