6.9 Earthquake is Strongest in Hawai‘i in 40+ Years

Maui Now graphics. Background image courtesy USGS.

UPDATE:

There is no tsunami expected after a 6.9 (preliminary magnitude 6.0) earthquake reported at 12:33 p.m. HST on Friday, May 4, 2018. This comes after a 5.4 earthquake (prelim 5.6) reported an hour earlier at 11:32 a.m.

Officials from the Hawaiian Volcano Observatory say the quake is the strongest in Hawaiʻi since 1975—and the largest in a series of strong earthquakes that began at 11:32 a.m. today.

“Remember to drop, cover, and hold on during strong earthquakes. Most common injuries come from falling objects,” said HVO’s seismic network manager Brian Shiro. “The earthquakes are related to the ongoing volcanic activity in Kīlauea’s East Rift Zone and reflect adjustments beneath the south flank of the volcano. Additional strong, damaging earthquakes are possible.”

Background image courtesy USGS. Graphic: Maui Now/Wendy Osher.

Numerous aftershocks under the south flank and summit areas of Kīlauea Volcano have already occurred, the largest of which was magnitude-4.9 at 2:37 p.m. The HVO notes that strong aftershocks should be expected, and could likely occur for weeks to months into the future.

According to the Hawaiian Volcano Observatory: “Like the magnitude-5.0 earthquake yesterday, rockfalls and ash plumes in the Pu‘u ‘Ō‘ō crater were triggered by today’s earthquake sequence. No other changes at Kīlauea have been observed, but HVO scientists are closely monitoring the data.”

The Pacific Tsunami Warning Center says there is no tsunami expected, however, some areas may have experienced strong shaking.

• The agency also says some areas of Hawaiʻi Island experienced small sea level fluctuations including the following measurements:Hilo 20 cm amplitude
• Kapoho 40 cm amplitude
• Honuapo 15 cm amplitude

The PTWC says fluctuations are now diminishing at all locations.

The USGS reports that the second, large quake occurred at a depth of 5 km and was located within the following parameters:

• 10 miles SE of Fern Forest, HI
• 10 miles SSE of Eden Roc, HI
• 10 miles SW of Leilani Estates, HI
• 23 miles S of Hilo, HI
• 225 miles SE of Honolulu, HI

Previous Post:

There is no tsunami expected after a 5.4 (preliminary magnitude 5.6) earthquake reported at 11:33 a.m. HST on Friday, May 4, 2018 on the South Flank of the Kīlauea Volcano on Hawaiʻi Island. The Pacific Tsunami Warning Center says some areas may have experienced strong shaking.

Note: The earthquake was initially listed as a 5.6 magnitude quake, and was downgraded to a 5.3, then upgraded again to 5.7, and downgraded once more to 5.4 by the USGS. The agency continues to review the data on the event, but authorities have already confirmed that no tsunami is expected.

Hawaiʻi County officials say, “As in all earthquakes, be aware of the possibility of aftershocks. If the earthquake was strongly felt in your area, precautionary checks should be made for any damages; especially to utility connections of gas, water, and electricity.”

Hawai’i County officials say the earthquake was not large enough to cause a tsunami.

The quake was located at a depth of 6 km and was located within the following preliminary parameters:

11 miles SE of Fern Forest, HI
12 miles SSE of Eden Roc, HI
12 miles SW of Leilani Estates, HI
26 miles S of Hilo, HI
227 miles SE of Honolulu, HI