Submarine volcanoes add to ocean soundscape

December 04, 2017

WASHINGTON, D.C., December 4, 2017 -- Most volcanoes erupt beneath the ocean, but scientists know little about them compared to what they know about volcanoes that eject their lava on dry land. Gabrielle Tepp of the Alaska Volcano Observatory and the U.S. Geological Survey thinks that with improved monitoring, scientists can learn more about these submarine eruptions, which threaten travel and alter the ocean soundscape.

During the 174th Meeting of the Acoustical Society of America, held Dec. 4-8, 2017, in New Orleans, Louisiana, Tepp will discuss the challenges and benefits of remote monitoring and what it can teach us about submarine volcanoes.

"It's very difficult to study underwater volcanoes because it's hard to put instruments in the water, especially long-term," Tepp said.

Depending on the size and depth of an underwater eruption, gas and ash may never break the ocean surface, or the gas and ash could create a volcanic plume with the potential to interfere with air travel. "The ocean is a big place so it's pretty unlikely that you're going to have a situation where a ship haphazardly wanders over an eruption, but there are a few that have come close," Tepp said. These unpredictable eruptions may also create a floating blanket of rocks, called a pumice raft, which can clog harbors and damage boats.

Tepp is presenting observations from two submarine volcanoes: Ahyi, a seamount in the Northern Mariana Islands in the Pacific Ocean, and Bogoslof, a shallow submarine volcano in the Aleutian Islands. The volcanoes made very different sounds, suggesting that different processes occurred during eruption. In 2014, Ahyi erupted for two weeks, with short, repetitive gunshotlike explosions every few minutes. In 2016 and 2017, Bogoslof had more sustained eruptions, lasting minutes to hours, which occurred every few days.

Evidence of these eruptions showed up on distant seismometers, which measure waves passing through the ground to record earthquakes, and hydrophone arrays that pick up underwater sound to detect covert nuclear detonations. When volcanoes erupt directly into the water, the sounds can travel for thousands of miles before dissipating.

Questions remain, however, such as if seismometers are sufficient for remote monitoring or if the more accurate information provided by cabled hydrophone arrays is worth the greater expense. Researchers are also interested in how the movement of waves from water into rock, and vice versa, affects signal detection.

Tepp and colleagues at National Oceanic and Atmospheric Administration and USGS recently deployed a hydrophone array in the Northern Mariana Islands. They will collect the data next summer and hope to determine where and how often local volcanoes erupt to see if the area needs better hazard monitoring.

Due to the long distances that eruption signals travel, they likely show up as anomalies on far-off monitoring devices used to study earthquakes, land-based volcanoes or even whale songs.

"Eruptions that create a loud enough sound, in the right location, can travel pretty far, even from one ocean to another," Tepp said. "It makes you wonder, how many of these signals have we seen on distant instruments where nobody knew what they were, and it's a submarine volcano from halfway around the world?"
-end-
Abstract: 1aAO5: "The Sounds of Submarine Volcanoes," by Gabrielle Tepp, Matthew Haney, John Lyons, Robert Dziak, Joe Haxel, Del Bohnenstiehl and William Chadwick, is at 9:05-9:20 AM CST, Monday, Dec. 4, 2017, in Salon F/G/H in the New Orleans Marriott. https://asa2017fall.abstractcentral.com/s/u/OajXUcch9zc

MORE MEETING INFORMATION

USEFUL LINKS

Main meeting website: http://acousticalsociety.org/content/174th-meeting-acoustical-society-america

Technical program: https://asa2017fall.abstractcentral.com/index.jsp

Meeting/Hotel site: http://acousticalsociety.org/content/174th-meeting-acoustical-society-america#hotel

Press Room: http://acoustics.org/world-wide-press-room/

PRESS REGISTRATION

We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact Julia Majors (jmajors@aip.org, 301-209-3090), who can also help with setting up interviews and obtaining images, sound clips or background information.

LIVE MEDIA WEBCAST

A press briefing featuring will be webcast live from the conference Tuesday, Dec. 5, 2017, in room Studio 1 at the New Orleans Marriott. Time to be announced. Register at https://www1.webcastcanada.ca/webcast/registration/asa617.php to watch the live webcast.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA

The Acoustical Society of America exists to generate, disseminate, and promote the knowledge and practical applications of acoustics. Two society meetings are held each year throughout the U.S. and Canada where acousticians can exchange information with various other researchers. For more information: http://acousticalsociety.org/

Acoustical Society of America

Related Volcanoes Articles from Brightsurf:

Crystals reveal the danger of sleeping volcanoes
Most active volcanoes on Earth are dormant and are normally not considered hazardous.

Stressed out volcanoes more likely to collapse and erupt, study finds
An international study led by Monash scientists has discovered how volcanoes experience stress.

Nanocrystals make volcanoes explode
Tiny crystals, ten thousand times thinner than a human hair, can cause explosive volcanic eruptions.

Scientists discover volcanoes on Venus are still active
A new study identified 37 recently active volcanic structures on Venus.

How volcanoes explode in the deep sea
Explosive volcanic eruptions are possible deep down in the sea -- although the water masses exert enormous pressure there.

How drones can monitor explosive volcanoes
Due to high risk for researchers, the imaging of active volcanoes has so far been a great challenge in volcanology.

A tale of two kinds of volcanoes
At an idyllic island in the Mediterranean Sea, ocean covers up the site of a vast volcanic explosion from 3200 years ago.

Peeking at the plumbing of one of the Aleutian's most-active volcanoes
A new approach to analyzing seismic data reveals deep vertical zones of low seismic velocity in the plumbing system underlying Alaska's Cleveland volcano, one of the most-active of the more than 70 Aleutian volcanoes.

In death of dinosaurs, it was all about the asteroid -- not volcanoes
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers.

Breathing? Thank volcanoes, tectonics and bacteria
A Rice University study in Nature Geoscience suggests Earth's first burst of oxygen was added by a spate of volcanic eruptions brought about by tectonics.

Read More: Volcanoes News and Volcanoes Current Events
Brightsurf.com 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 Amazon.com.