Pacific Ocean sea-level records of the 5 March 2021 triplet of tsunamis

On 5 March 2021, at 2.27 AM local time (4 March 2021, 13:27:34 UTC), a Mw 7.3 earthquake woke up the North Island of New Zealand with strong and long shaking. Its epicentre was located about 170 km NE offshore Gisborne in the Hikurangi subduction zone. This was the first tsunami of a triplet occurring on the same day. The tsunami propagated from the source region to the north shore of New Zealand, with a very localised and limited impact. Maximum amplitudes of ~32.3 cm and ~6.6 cm were respectively recorded at East Cape (LOTT) and North Cape (NCPT) coastal tsunami gauges, located ~105 km and ~660 km away from the epicentre. At 6.41 AM (17:41:23 UTC), 4 hours and 14 minutes later, another earthquake triggered a tsunami in the southwestern Pacific region with a magnitude Mw 7.4 earthquake. This was located further north (~ 900 km) than the previous one, 50 km south of Raoul Island (New Zealand) on the Kermadec subduction zone. At 8.28 AM (19:28:33 UTC), 1 hour and 47 minutes later, a Mw 8.1 earthquake occurred very close to the earlier Mw 7.4 earthquake, 80 km southeast of Raoul Island. It triggered a third tsunami that was recorded on New Zealand DART stations and coastal gauges, and all around the Pacific Ocean. Those data presents the arrival times and amplitudes of the first and third tsunamis on the New Zealand coastal gauges. DOI: https://doi.org/10.21420/P606-J332 Cite data as: GNS Science. (2021). Pacific Ocean sea-level records of the 5 March 2021 triplet of tsunamis [Data set]. GNS Science. https://doi.org/10.21420/P606-J332