Featured Research

from universities, journals, and other organizations

Scientists Search For Seafloor Eruption

Date:
March 13, 2005
Source:
University Of Washington
Summary:
The most intense swarms of earthquakes detected in the last 10 to 12 years on the far edge of the Juan de Fuca plate could indicate the eruption of magma from the seafloor or an underwater volcano. Between 50 and 70 earthquakes an hour, most of them small, were occurring at the end of February at a spot some 200 miles off the Canadian coast.

Marv Lilley, UW oceanographer involved with the expedition, goes over seafloor maps with Deb Glickson, UW graduate student, and John Delaney, UW oceanographer, prior to the start of the journey.
Credit: Photo courtesy of University Of Washington

The most intense swarms of earthquakes detected in the last 10 to 12 years on the far edge of the Juan de Fuca plate could indicate the eruption of magma from the seafloor or an underwater volcano. Between 50 and 70 earthquakes an hour, most of them small, were occurring at the end of February at a spot some 200 miles off the Canadian coast.

Related Articles


University of Hawaii's Jim Cowen, chief scientist, and National Atmospheric and Oceanic Administration's Ed Baker, co-chief scientist, are at sea now leading an expedition at the Endeavour Segment, the site of the quakes. The Endeavour Segment is located in deep water and the quakes are not of a magnitude that would cause noticeable effects on land in Canada or the United States.

Reports from the expedition are available online here. As of March 8, the site said the number of quakes had calmed in recent days.

The scientists are on board the Thomas G. Thompson, the 274-foot research vessel operated by the University of Washington, and will return to Seattle March 11. The project is a rapid-response cruise funded by the National Science Foundation and the National Atmospheric and Oceanic Administration, with cooperation from the Canadian government.

There have been six rapid-response cruises to investigate seismic activity on the Juan de Fuca plate since 1991, the most recent having been in 2001 led by Marv Lilley, University of Washington oceanographer.

Nowhere have scientists been in position to document lava flows while they are erupting, other than in Hawaii where Kilauea lavas flow into the sea, Lilley says. They've been tantalizingly close a few times out on the Juan de Fuca Ridge, once detecting fresh lava that was still hot enough to have diffuse water flowing out of it and another time arriving to find small glass shards still suspended in the water.

Even if there is no chance to witness lava flows, scientists are eager to arrive at the site as quickly as possible to measure changes that rapidly unfold following an eruption. Fluids discharged into the ocean during such events can form a billowing plume half a mile thick and stretching 6 miles in diameter, substantially changing water temperature and chemistry. Microorganisms flourish, increasing in such abundance that scientists say water near eruption sites can appear blizzard-like as it becomes laden with individual organisms and those that have formed into trailing mats and strings in the water.

"What's expelled gives scientists a view into what's deep in the seafloor, in places scientists can't reach," chief scientist Cowen says.

The swarms of quakes started Feb. 27 and lasted long enough that co-chief scientist Ed Baker told the Seattle Times before the expedition left port that, "We're pretty sure lava is moving."

The seafloor quakes are monitored by SOSUS, the SOund SUrveillance System, that can "hear" sound waves generated by seismic events, submarines or whales.

The swarms are centered about 200 miles west of Vancouver Island, British Columbia, at 48 degrees N and 129 degrees W. The seafloor is about a mile and a half below the surface there. As of March 4, fewer than 10 quakes an hour were being detected.

The site is on the Endeavour Segment, on the northern part of the Juan de Fuca Ridge. The ridge is where the Juan de Fuca plate is pulling away from a neighboring plate. Molten lava typically oozes up into the open spaces creating new seafloor at a pace of usually only inches a year. There can be more rapid spreading, however, during volcanic eruptions and earthquakes. Fields of hydrothermal vents form where seawater circulates beneath the seafloor gaining heat and chemicals until the fluids vent back into the ocean, sometimes like geysers. As the fluids mix with cold seawater the chemicals separate and solidify, sometimes piling up into impressive mounds, spires and chimneys.

Researchers will sample sea water, take images using a camera sled, collect rock fragments and deploy three to four floats made especially to be able to float along with the plume of vent fluids for several months.

There is the possibility scientists will find something other than an eruption underway. A swarm of earthquakes off the coast in 2001 caused an area of the seafloor to draw in surrounding seawater for more than a year. It was a surprising twist for scientists who visited the site expecting to find hot water, and possibly magma, being expelled, says Lilley, leader of that expedition and co-author of a paper last July in Nature about the event. The void created by the earthquakes was under negative pressure, drawing water down into hundreds of feet of sediments, something scientists had never observed before.

Scientists, graduate students and undergraduates on the current expedition are from the University of Hawaii, University of Washington, University of Miami, Oregon State University, NOAA's Pacific Marine Environmental Laboratory, Woods Hole Oceanographic Institution and Scripps Institution of Oceanography, as well as students from Canada, Hong Kong and Switzerland.


Story Source:

The above story is based on materials provided by University Of Washington. Note: Materials may be edited for content and length.


Cite This Page:

University Of Washington. "Scientists Search For Seafloor Eruption." ScienceDaily. ScienceDaily, 13 March 2005. <www.sciencedaily.com/releases/2005/03/050309104200.htm>.
University Of Washington. (2005, March 13). Scientists Search For Seafloor Eruption. ScienceDaily. Retrieved November 22, 2014 from www.sciencedaily.com/releases/2005/03/050309104200.htm
University Of Washington. "Scientists Search For Seafloor Eruption." ScienceDaily. www.sciencedaily.com/releases/2005/03/050309104200.htm (accessed November 22, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, November 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
5 Hot Months, 1 Warm Year And All The Arguments To Follow

5 Hot Months, 1 Warm Year And All The Arguments To Follow

Newsy (Nov. 21, 2014) The NOAA released statistics Thursday showing October was the fifth month this year with record temps and 2014 will likely be the hottest on record. Video provided by Newsy
Powered by NewsLook.com
Nations Pledge $9.3 Bn for Green Climate Fund

Nations Pledge $9.3 Bn for Green Climate Fund

AFP (Nov. 20, 2014) Nations meeting in Berlin pledge $9.3 billion (7.4 bn euros) for a climate fund to help poor countries cut emissions and prepare for global warming, just shy of a $10bn target. Duration: 00:46 Video provided by AFP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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