HILO, Hawai'i — A magnitude-4.7 earthquake shook the undersea volcano Lo'ihi early yesterday, but scientists with the U.S. Geological Survey said they had not been contacted by anyone who reported feeling the temblor on shore.

The earthquake was part of a swarm of seismic activity near Lo'ihi that began about 10 p.m. Tuesday and ended about 3 p.m. yesterday. That activity included several dozen smaller quakes, scientists said.

Lo'ihi is an active volcano south of Kilauea volcano and about 19 miles off the coast of the Big Island. The Lo'ihi seamount is about 3,200 feet below the surface of the ocean.

The 4.7 earthquake was the largest since July 17, when a magnitude-5.2 earthquake jolted Lo'ihi.

Steven Brantley, deputy scientist-in-charge at the USGS Hawaiian Volcano Observatory, said there was no indication the earthquake signaled the start of a new eruption or was caused by the movement of lava.

The quake more likely was caused by a "structural adjustment," possibly as the mass of the volcano settled slightly on the sea floor, Brantley said. Scientists said the earthquake was centered five miles east of the Lo'ihi seamount and 17 miles deep.