Frequent quakes at Lo‘ihi no threat to island, HVO says

An increase in seismic activity around the youngest Hawaiian volcano poses no immediate danger to Hawaii Island, geologists report.

According to a report from the Hawaiian Volcano Observatory, more than 100 earthquakes have been detected around Lo‘ihi seamount, the underwater volcano off the southeast coast of Hawaii Island, between Monday morning and today.

Of those earthquakes, 79 were magnitude 2, while another 19 were magnitude 3 or higher. They originated at depths of between 0.6 and 6 miles beneath the volcano’s surface, or 2.2 to 7.7 miles below sea level.

The Seamount typically sees fewer than three earthquakes daily, which generally do not reach magnitudes as high as 2.

The report, which was released shortly after noon today, stated that the earthquake rate has slowed to less than four per hour after peaking at 14 earthquakes in a single hour Monday afternoon.

The spike in earthquakes — which HVO refers to as an “earthquake swarm” — may represent a movement of magmatic fluids within the volcano. If the earthquakes were to become shallower, it could indicate the beginning of a submarine eruption.

Other earthquake swarms have occurred at Lo‘ihi in the past, most recently in 2017. The last recorded eruption of the volcano occurred in 1996, which preceded a nearly month-long swarm of more than 4,000 earthquakes.

HVO reported that an eruption and partial summit collapse at Lo‘ihi “might generate very small local tsunami waves.”