A preliminary magnitude 4.6 earthquake shook the deep ocean off the Kona coast of Hawaiʻi on Thursday night, giving parts of the Big Island a noticeable jolt but no major trouble. The quake hit at about 8:17 p.m. HST and was reported felt in several areas, yet by early Friday there were no reports of damage or coastal flooding.
USGS located the epicenter at 19.238°N, 156.358°W, about 36.2 miles southwest of Kailua-Kona, at a depth of roughly 7 kilometers. The Pacific Tsunami Warning Center said the quake was not expected to generate a tsunami, while Maui Now reported that some communities did feel shaking.
Officials and scientists weigh in
In a recent Volcano Minute update, the USGS Hawaiian Volcano Observatory broke down what is going on beneath Hawaiʻi’s feet. Many of the quakes in the region right now are classified as deep flexure events, and the agency noted that "because these flexure events happen deep within the Earth, their shaking travels farther, making them more widely felt." In that same USGS HVO update, scientists stressed the difference between these deeper quakes and the shallower, magma-related earthquakes that can point more directly to volcanic unrest.
What residents should do
The Pacific Tsunami Warning Center’s determination that no tsunami was expected was passed along by local officials and news outlets, according to Maui Now. Even when a tsunami is unlikely, USGS HVO reminds residents that if they feel shaking, the first move should be to "drop, cover, and hold on." People in coastal areas are also urged to head to higher ground and stay put until authorities confirm that no tsunami was generated.
How this fits into recent activity
Seismologists say Thursday’s offshore jolt lines up with a recent pattern of deep, widely felt earthquakes rather than signaling a brand-new volcanic crisis. Local media and county officials have been keeping a close watch ever since a stronger magnitude 6.0 quake in late May caused localized damage in South Kona, a reminder that even in a quake-hardened community, a big one can still knock things around. Earlier coverage of that incident was documented by Big Island Now, and agencies say they continue to monitor both seismic shaking and coastal conditions.
