Seismic Swarm Continues: More than 100 Earthquakes Recorded

Earthquake map showing recent seismic activity near Kilauea. Image courtesy Hawaii Volcanoes Observatory/ USGS.

By Wendy Osher

A seismic swarm first recorded early Wednesday morning has resulted in more than 100 earthquakes between the Kilauea and Mauna Loa Volcanoes on Hawai’i Island.

Officials at the US Geological Survey’s Hawaiian Volcano Observatory say the event started at 1:17 a.m., HST, on Wednesday, February 22, 2012.

Since then, a series of mostly small quakes, two measuring above 4 in magnitude, have been reported.  The largest, 4.3 quake occurred at 3:52 a.m. today, (Friday, February 24, 2012).  The other was a 4.1 quake, reported at 9:02 p.m. last night, (Thursday, February 23, 2012).

“It’s likely that high rates of seismicity could continue in this area for several days,” said HVO Scientist in Charge, Jim Kauahikaua.

Sake map from 2/24/12 3:53 a.m. quake near the Kilauea Summit. Map courtesy USGS & Hawaii Volcanoes Obersvatory.

Kauahikaua said the earthquake swarm has not caused any obvious changes in Kilauea’s magma plumbing system or ongoing eruptions; but that the magnitude 4.3 quake did cause a small rockfall in the active vent located within Halema‘uma‘u Crater at the summit of Kilauea.

HVO officials say the earthquakes are located about 3 miles north-northwest of Kilauea volcano’s summit, near Namakanipaio in Hawai‘i Volcanoes National Park, at depths of 1 to 3 miles.

As of 9 a.m., the USGS had received 74 reports of people who say they felt the Thursday quake at 9:02 p.m.; and 60 reports from people who say they felt today’s 3:53 a.m. quake.

At the Hawaii Volcano Observatory building, which is located less than 2.5 miles from the swarm center, staff reported fallen books, and some small ceiling fixtures were dislodged.

Several residents from the Volcano Golf Course subdivision, also reported items falling from shelves.

According to HVO officials, the earthquake swarm is located at the north end of the Ka‘oiki Pali, near the boundary between Mauna Loa and Kilauea volcanoes.

This area, officials say, has experienced previous seismic swarms in 1990, 1993, 1997, and 2006, each of which lasted from 1 day to several weeks.

***Supporting information courtesy Hawaii Volcanoes Observatory.