Featured Research

from universities, journals, and other organizations

Volcanoes sound-off on the life-cycles of eruptions

Date:
May 8, 2012
Source:
Acoustical Society of America (ASA)
Summary:
Volcanoes emit a broad spectrum of sonic energy. In the case of basaltic eruptions, most of that acoustical energy in the infrasound range. A new study reveals that this low-frequency sound can give scientists an enhanced understanding of the behavior of volcanoes and a tool to monitor the lifecycles of their eruptions.

From low rumblings to concussive blasts, volcanoes emit a broad spectrum of sonic energy. In the case of basaltic eruptions, most of that acoustical energy in the infrasound range, at frequencies below the range of human hearing. A new study reveals that this low-frequency sound can give scientists an enhanced understanding of the behavior of volcanoes and a tool to monitor the lifecycles of their eruptions.

According to geophysicist Aurιlien Dupont of the Pusan National University in South Korea, as gasses percolate through underground magma they produce specific low-frequency sounds. "By recording and analyzing the sounds emitted by basaltic volcanoes," Dupont said, "volcanologists can use infrasound to measure the flow and behavior of magma and better survey volcanic activity." He is presenting his research at the Acoustics 2012 meeting in Hong Kong, May 13-18, a joint meeting of the Acoustical Society of America (ASA), Acoustical Society of China, Western Pacific Acoustics Conference, and the Hong Kong Institute of Acoustics.

By tracking the main sources of infrasound during the eruptions, the researcher discovered that the gas pockets trapped in the magma decreased in size throughout the course of the eruption until they disappeared at the eruption's end. "The gas volume fraction constantly decreases in the volcanic conduit during a basaltic eruption," Dupont said.

Basaltic magma has low viscosity and relatively low gas content so it flows easily, producing volcanoes with gentle slopes and impressive displays like lava fountains and rivers of lava.

As the magma travels from the underground magma reservoir to the surface, the gas that is in suspension begins to expand. This expansion produces distinctive infrasound profiles. Once the magma reaches the surface and is under only atmospheric pressure, the gas is able to bubble away and escape.

Dupont made his observations at the Piton de la Fournaise volcano on Reunion Island, which is in the Indian Ocean. This volcano erupts often and is a perfect field laboratory to test and adapt new survey techniques, like infrasonic monitoring.

For this research, Dupont used condenser microphones and microbarometers to detect the sound produced from the gas flow. He then correlated that sound profile with observations of volcanic gasses escaping from vents in and around the crater. "If no volcanic gas escapes anymore from the vents, detections stop and the eruption is over," he noted. "Infrasound can accurately characterize the beginning and the end of an eruption." The series of volcanic noises, which were recorded between 1992 and 2008, brings new constraints to the functioning of the eruptions.

"The quantitative analysis of the noise produced by the gas flow allows us not only to understand a natural system as complex as a volcano but allows us also to better monitor it," concludes Dupont.


Story Source:

The above story is based on materials provided by Acoustical Society of America (ASA). Note: Materials may be edited for content and length.


Cite This Page:

Acoustical Society of America (ASA). "Volcanoes sound-off on the life-cycles of eruptions." ScienceDaily. ScienceDaily, 8 May 2012. <www.sciencedaily.com/releases/2012/05/120508152009.htm>.
Acoustical Society of America (ASA). (2012, May 8). Volcanoes sound-off on the life-cycles of eruptions. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/05/120508152009.htm
Acoustical Society of America (ASA). "Volcanoes sound-off on the life-cycles of eruptions." ScienceDaily. www.sciencedaily.com/releases/2012/05/120508152009.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) — The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) — Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) — A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins