A magnitude-6 earthquake struck off the west coast of the Island of Hawaiʻi on Friday, May 22, at 9:46 p.m. HST, generating a record-breaking 7,000 "Did You Feel It?" reports to the U.S. Geological Survey (USGS).
The earthquake, centered 14 miles (22 km) below sea level just south of Hōnaunau-Nāpōʻopoʻo, was identified as a lithospheric flexure event. This phenomenon occurs as the Pacific Plate adjusts to the immense weight of the Hawaiian Islands and is not directly related to volcanic activity, despite its mapped proximity to Mauna Loa. Strong to very strong shaking was reported closest to the epicenter, indicating the potential for light to moderate damage.
The USGS Hawaiian Volcano Observatory (HVO) and the NOAA Pacific Tsunami Warning Center (PTWC) responded swiftly. HVO staff began analyzing data even as shaking occurred, sending out preliminary automated estimates. PTWC quickly issued a statement confirming that no tsunami had been generated. HVO later revised the earthquake's parameters, determining it was a magnitude-6.0 at a depth of 14 miles, and clarified that the event was due to Pacific Plate flexure, not magma movement within Mauna Loa.
This recent tremor set a new record for the State of Hawaii in terms of community-submitted felt reports, surpassing the 3,500 reports for a magnitude-6.2 earthquake in 2021 and the 3,000 reports for the damaging magnitude-6.7 Kīholo Bay earthquake in 2006. The event serves as a reminder that Hawaii is one of the most seismically active locations in the United States, prompting the USGS to reiterate the importance of practicing "Drop, Cover, and Hold On" during an earthquake and moving inland if near the coast.
In related geological activity, Kīlauea volcano continues episodic eruptions within its summit caldera, currently at an ADVISORY alert level. Models suggest another fountaining episode is likely between May 28 and May 30. Mauna Loa remains at a NORMAL alert level and is not erupting.