Earthquakes Caused by Clogged Magma a Warning Sign of Eruption, Study Shows

Mar 17, 2014
Credit: Cyrus Read/Alaska Volcano Observatory

New research in Geophysical Research Letters examines earthquake swarms caused by mounting volcanic pressure which may signal an imminent eruption. The research team studied Augustine Volcano in Alaska which erupted in 2006 and found that precursory earthquakes were caused by a block in the lava flow.

36 hours before the first magmatic explosions, a swarm of 54 earthquakes was detected across the 13-station seismic network on Augustine Island. By analyzing the resulting seismic waves, the authors found that the earthquakes were being triggered from sources within the volcano's magma conduit.

"Our article talks about a special type of volcanic that we think is caused by lava breaking, something that usually can't happen because lava is supposed to flow more like a liquid, rather than crack like a piece of rock," said Dr. Helena Buurman from the University of Alaska Fairbanks. "Much like breaking a piece of chewing gum by stretching it really fast, lab tests show that hot lava can break when stretched quickly enough under certain pressures like those that you might find in the conduit of a volcano. "

The authors found that over the course of the two hour swarm, the earthquakes' focus moved 35 meters deeper down into the magma conduit, an indication that the conduit was becoming clogged. The resulting buildup of pressure may have contributed to the the next day.

"We think that these earthquakes happened within the lava that was just beginning to erupt at the top of Augustine. The earthquakes show that the flow was grinding to a halt and plugging up the system. This caused pressure to build up from below, and resulted in a series of large explosions 36 hours later," concluded Dr. Buurman. "We believe that these types of earthquakes can be used to signal that a volcano is becoming pressurized and getting ready to explode, giving scientists time to alert the public of an imminent eruption."

Explore further: Study finds existence of large, deep magma chamber below Kilauea volcano

More information: Helena Buurman, Michael E. West, 'Magma fracture and hybrid earthquakes in the conduit of Augustine Volcano', Geophysical Research Letters, DOI: 10.1002/2013GL057864

add to favorites email to friend print save as pdf

Related Stories

Lava floods the ancient plains of Mars

Mar 07, 2014

Two distinct volcanic eruptions have flooded this area of Daedalia Planum with lava, flowing around an elevated fragment of ancient terrain.

Unique sighting of lava solves mystery

Nov 08, 2013

(Phys.org) —Scientists have made the first ever observations of how a rare type of lava continues moving almost a year after a volcanic eruption.

Recommended for you

Jeju Island is a live volcano, study reveals

7 hours ago

In Jeju, a place emerging as a world-famous vacation spot with natural tourism resources, a recent study revealed a volcanic eruption occurred on the island. The Korea Institute of Geoscience and Mineral ...

Has Antarctic sea ice expansion been overestimated?

7 hours ago

New research suggests that Antarctic sea ice may not be expanding as fast as previously thought. A team of scientists say much of the increase measured for Southern Hemisphere sea ice could be due to a processing ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Lex Talonis
3 / 5 (2) Mar 17, 2014
Well oh duh.

A constipated volcano - is surely going to fart and groan before it shits it's self.

Earth Mechanics - 101.

Ask anyone who has used a shovel - minus a PHD.