Epicenter of the 8:41 p.m. quake Thursday (Oct 15). Map courtesy of USGS

Magnitude
3.9 (preliminary)

Times
2015-10-16 06:41:50 (UTC)
2015-10-15 20:41:50 HST

Nearby Cities
18km (11mi) S of Fern Acres, Hawaii
29km (18mi) SSW of Hawaiian Paradise Park, Hawaii
42km (26mi) S of Hilo, Hawaii
103km (64mi) ESE of Kailua-Kona, Hawaii
363km (226mi) SE of Honolulu, Hawaii

At 8:41 p.m. HST Thursday (Oct 15) an earthquake of 3.9 magnitude (preliminary) shook Hawaii Island. The epicenter was located in Hawaii Volcanoes National Park south southeast of Pu‘u ‘O‘o Crater at a depth of 4.48 miles (7.21 km).

According to the USGS website the quake was felt in Puna, Hilo and on the Hamakua Coast in Papaikou, Pepeekeo, Hakalau, Laupahoehoe and Honomu.

There is no tsunami advisory from this earthquake.

Seismograph readout of the 8:41 p.m. HST quake Thursday (Oct 15) and an aftershock to the right of it on the timeline.

The quake was centered makai of Pu‘u ‘O‘o closer to the coastline. Map via USGS

USGS: How large does an earthquake have to be to cause a tsunami?

Magnitudes below 6.5
Earthquakes of this magnitude are very unlikely to trigger a tsunami.

Magnitudes between 6.5 and 7.5
Earthquakes of this size do not usually produce destructive tsunamis. However, small sea level changes may be observed in the vicinity of the epicenter. Tsunamis capable of producing damage or casualties are rare in this magnitude range but have occurred due to secondary effects such as landslides or submarine slumps.

Magnitudes between 7.6 and 7.8
Earthquakes of this size may produce destructive tsunamis especially near the epicenter; at greater distances small sea level changes may be observed. Tsunamis capable of producing damage at great distances are rare in the magnitude range.

Magnitude 7.9 and greater
Destructive local tsunamis are possible near the epicenter, and significant sea level changes and damage may occur in a broader region.

Note that with a magnitude 9.0 earthquake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible. To date, the largest aftershock recorded has been magnitude 7.1 that did not produce a damaging tsunami.