The U.S. Geological Survey's Hawaiian Volcano Observatory said the temblor was the largest in that particular area in at least the last 50 years. Since 1998, only a few earthquakes with magnitudes greater than 4.0 have occurred at shallow depths beneath the upper-east rift zone.

The first earthquake at 9:13 a.m. was located beneath the upper-east rift zone of Kilauea volcano near Puhimau crater, and was about a mile deep.

A magnitude-4.1 aftershock followed at 9:33 a.m. That quake was about a mile farther downrift beneath Koko'olau crater.

USGS said the earthquakes are the largest so far in a flurry of earthquakes in the upper-east and southwest rift zones that started on May 12.

Earthquakes sometimes signal the beginning of an eruption or a change in the ongoing eruption, but the recent earthquake flurry has not been accompanied by any unusual swelling of the summit or other signs of unusual summit activity, scientists said.