The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.5 earthquake located north of the Island of Molokai on Friday at 12:04 a.m.
The earthquake was located 34 miles north of Maunaloa, Molokai, at a depth of about 22 miles
HVO's seismic records show that 10 earthquakes of magnitude 3 or larger have occurred north of Moloka`i in the past 20 years, including a magnitude-4.1 earthquake on May 20, 2005.
Wes Thelen, HVO's Seismic Network Manager, says that earthquakes in this area are not uncommon and are typically caused by a structural adjustment of the mantle in response to the weight of the Hawaiian Islands. "This is a good reminder that the Island of Hawai`i is not the only Hawaiian island prone to earthquakes," he added.
No aftershocks have been recorded, and, according to Thelen, aftershocks typically do not follow earthquakes at these depths in the mantle.
Today's earthquake was felt on several Hawaiian islands, from Maui to Kauai. The USGS "Did you feel it?" Web site (http://earthquake.usgs.gov/eqcenter/dyfi/) received more than 60 felt reports within the first hour of the earthquake. Thus far, there have been no reports of damage.
The earthquake is not expected to have any effect on Kilauea's ongoing eruptions. "HVO monitoring networks have not detected any significant changes in activity at the summits or rift zones of Kilauea or other Hawaiian volcanoes," said Jim Kauahikaua, HVO's Scientist-in-Charge.
The magnitude was initially estimated at 4.0, but more detailed seismic analyses resulted in a final magnitude of 4.5.
Due to a technical glitch, the USGS National Earthquake Information Center and Hawaiian Volcano Observatory webpages briefly posted two earthquakes north of Moloka`i, but only one earthquake occurred.