Triggering Of Volcanic Eruptions

October 28, 1998

Could tiny deformations deep within the interiors of volcanoes hold clues to volcanic eruption prediction? What role do earthquakes, with epicenters far away from these volcanoes, play in disturbing the volcanoes?

In a paper published this week in the journal Nature, Alan T. Linde and I. Selwyn Sacks, scientists at the Carnegie Institution's Department of Terrestrial Magnetism in Washington, D.C., assert that there is a pressing need to continuously monitor, using high-sensitivity methods, the deformation of active volcanoes. These small deformations, caused by seismic wave disturbances of the subterranean magma chambers, may point to a volcano's imminent eruption.

While earthquakes and volcanoes result from the large-scale effects of plate tectonics, it has generally been thought that particular instances of earthquakes and eruptions are not directly related. But, upon noting the relationship between the 1992 Landers (southern California) earthquake and the ensuing seismicity and deformations at eastern California's Long Valley Caldera, Linde and Sacks undertook a study to investigate a possible link between earthquakes, small deformations, and potential volcanic eruptions. By examining the historical record of volcanic eruptions and earthquakes (using catalogs of the Smithsonian Institution's Global Volcanism Network and the U. S. Geological Survey's National Earthquake Information Center), the authors show a statistically significant correlation between large magnitude (greater than or equal to 7.0 on the Richter scale) earthquakes and volcanic eruptions separated by a distance up to 750 km. They exclude the phenomenon of volcanic earthquakes (small-magnitude seismicity or earthquakes accompanying eruptions) by considering only large-magnitude earthquakes, and use only explosive-type (as opposed to eruptions with a very fluid lava) eruptions in the data sets. The time frame between earthquakes and eruptions must be within a few days. Volcanic earthquakes are excluded because they are not the cause of eruptions, merely a symptom of an eruption. The authors display their results graphically, and use a variation of bootstrap analysis to show that the effect is not simply due to chance.

Linde and Sacks also point out that within two days following an initial volcanic eruption, a subsequent eruption at a second volcano (up to 200 km distant) occurs much more frequently than would be randomly expected. This second, or paired eruption, may be caused by the passage of seismic waves from earthquakes associated with the primary eruption. These seismic waves may cause a pressure increase in the magma chambers, and if the pressure is already at a critical stage, an eruption may follow.

The authors feel it is important to increase geophysical monitoring at active volcanoes, using high-resolution strainmeters and tiltmeters installed in boreholes deep within the volcano. By watching even the smallest deformations of volcanoes, scientists may be able to predict volcanic activity more accurately and warn populations of impending eruptions. "This is a huge area where a lot of work is needed. Volcanoes give signs about when they are going to go off," says lead author Alan Linde. Their paper shows that a correlation does exist between strong earthquakes, the triggered deformation of volcanoes, and eruptions. By adding high-sensitivity data from monitoring instruments, scientists, in the future, will have new insights into the volcanic eruption process.
The Department of Terrestrial Magnetism (DTM), led by Sean S. Solomon, is one of five research arms of the Carnegie Institution of Washington, a nonprofit organization devoted to basic research and education in the physical and biological sciences. Scientists at DTM are engaged in studies in seismology, geochemistry, and the astronomical and planetary sciences. Other Carnegie departments are the Geophysical Laboratory, co-located with DTM in northwest Washington, D.C.; the Department of Plant Biology, in Stanford, CA; the Department of Embryology, in Baltimore, MD; and the Carnegie Observatories, in Pasadena, CA, and Las Campanas, Chile. The institution's president is Maxine F. Singer. Contact: Alan Linde at 301-588-1108,;
or Selwyn Sacks at 202-686-4370, ext. 388,;
or Pat Craig in the Carnegie news office at 202-939-1120.

Carnegie Institution for Science

Related Earthquake Articles from Brightsurf:

Healthcare's earthquake: Lessons from COVID-19
Leaders and clinician researchers from Beth Israel Lahey Health propose using complexity science to identify strategies that healthcare organizations can use to respond better to the ongoing pandemic and to anticipate future challenges to healthcare delivery.

Earthquake lightning: Mysterious luminescence phenomena
Photoemission induced by rock fracturing can occur as a result of landslides associated with earthquakes.

How earthquake swarms arise
A new fault simulator maps out how interactions between pressure, friction and fluids rising through a fault zone can lead to slow-motion quakes and seismic swarms.

Typhoon changed earthquake patterns
Intensive erosion can temporarily change the earthquake activity (seismicity) of a region significantly.

Cause of abnormal groundwater rise after large earthquake
Abnormal rises in groundwater levels after large earthquakes has been observed all over the world, but the cause has remained unknown due to a lack of comparative data before & after earthquakes.

New clues to deep earthquake mystery
A new understanding of our planet's deepest earthquakes could help unravel one of the most mysterious geophysical processes on Earth.

Fracking and earthquake risk
Earthquakes caused by hydraulic fracturing can damage property and endanger lives.

Earthquake symmetry
A recent study investigated around 100,000 localized seismic events to search for patterns in the data.

Crowdsourcing speeds up earthquake monitoring
Data produced by Internet users can help to speed up the detection of earthquakes.

Geophysics: A surprising, cascading earthquake
The Kaikoura earthquake in New Zealand in 2016 caused widespread damage.

Read More: Earthquake News and Earthquake Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to