Mauna Loa Alert Upgraded From Normal To Advisory

Jul 2, 2019

Mauna Loa as seen from the Humuula Trail to the summit of Mauna Kea.
Credit niksnut / CC BY-SA 2.0 / Flickr

Mauna Loa Volcano last erupted in 1984.  Since then, it’s had some restless times, but for the past year, has been at the normal, lowest, alert level. But recently things have been changing. 

Tina Neal, scientist in charge at Hawaiian Volcano Observatory, says scientists are continually monitoring Mauna Loa Volcano.

“For months now, we’ve been seeing some elevated activity at Mauna Loa Volcano. We’ve decided to upgrade the alert level to advisory from normal. That’s a one-step move,  just meaning we’re seeing slightly elevated earthquake counts and ground deformation rates.  This does not mean an eruption is imminent by any means. “

Neal says the decision to upgrade Mauna Loa’s alert level was partly based on an increasing number of small earthquakes, the largest on June 21st at 3.1 magnitude.  

“Around the turn of the year, we were seeing about 20 quakes per week.  Since early this year, we’ve been seeing 50 to 55 earthquakes per week.”

Although gas emissions have not increased, another factor is ground deformation.

“We’ve seen about 1 ½ inches of uplift near the summit of the volcano.  One and a half inches doesn’t sound like much, but it’s a respectable volume change, responding to magma being added to the shallow magma system beneath Mauna Loa.”

Neal says Hawaiian Volcano Observatory has seismometers, gas meters, tilt meters and more all around Mauna Loa and Kilauea – among other places—and monitoring goes on 24 hours a day.   She stresses that even though neither Mauna Loa nor Kilauea is likely to erupt soon, Big Island residents should always be prepared.