The underwater volcano “Hunga Tonga-Hunga Ha’apai” in Tonga has been experiencing ongoing volcanic activity since the 20th December 2021. From the 5th of January 2022 activity had decreased, but on the 15th it increased again with a large eruption occurring with a sonic boom that was heard hundreds of kms away. The event was recorded by seismic stations worldwide, including stations in the Irish National Seismic Network (INSN) (see figure below). The first signals originating from the Tonga event arrived ~15 hours after the event origin. A large plume of ash was visible on satellite images and the eruption was heard in Tonga, the surrounding islands and with reports from as far away as Alaska. The eruption also generated a tidal wave warning for the Pacific region.
