Featured Research

from universities, journals, and other organizations

Scientists Find Active Underwater Volcano East Of Samoa

Date:
May 23, 2000
Source:
Woods Hole Oceanographic Institution
Summary:
Marine geologists from the Woods Hole Oceanographic Institution (WHOI) and the Scripps Institution of Oceanography (SIO) have confirmed the existence of an active underwater volcano east of Samoa.

Marine geologists from the Woods Hole Oceanographic Institution (WHOI) and the Scripps Institution of Oceanography (SIO) have confirmed the existence of an active underwater volcano east of Samoa. The volcano, recently named Vailulu’u by local students, is located about 28 miles east of Ta’u Island and rises more than 16,400 feet from the seafloor to within 2,000 feet of the ocean surface. The scientists found billowing "smoggy" water in the summit and extending out for more than five miles.

Mapped and sampled last year for the first time, Stanley Hart of WHOI and Hubert Staudigel and Dave Willoughby of SIO returned in March of this year to search for evidence that the volcano is actively erupting. By towing an instrument behind the ship that measures the turbidity or particulate matter in the water column, the researchers were able to show that the summit crater of the volcano is filled with billowing "smoggy" water. This "smog" extends out from the top of the volcano, in the form of a halo, for more than five miles. Both the 1999 and 2000 cruises were funded by the National Science Foundation.

The scientists were working from the U.S.Coast Guard Icebreaker Polar Star, which was on its return trip from Antarctica after "summering" there since December. Helicopters from the ship picked up the scientists on Fiji March 19, and the ship arrived on top of the volcano the next day. The circular summit crater of Vailulu’u is 400 meters (about 1,300 feet) deep and 2,000 meters (about 6,500 feet) wide, and appears to be the location of the current volcanic activity.

The scientists first surveyed the water in and around Vailulu’u for turbidity, temperature and salinity using a "tow-yo" technique. While the ship steams slowly along a chosen track, the instrument package is continuously lowered and raised on the end of a cable, and the various readings are displayed on-deck in real time. The surveys indicated the "smog" outside the crater was restricted to a layer in the water between depths of 600 and 800 meters (about 1,950 to 2,600 feet deep), and is apparently being carried out of the crater and dispersed by ocean currents. Water samples were collected during the profiling, and these are being analyzed for chemical constituents that may shed light on the nature of the process forming the "smog."

The scientists also deployed five hydrophones, or underwater microphones, onto the upper reaches of the volcano, including the crater floor. These instruments will "listen" for and record earthquakes and other volcanic rumblings until they are retrieved next spring.

Hart and his colleagues say their finding of a dense smog layer justifies a return mission to Vailulu’u with a major exploration campaign utilizing submersibles and remotely operated vehicles (ROVs). Future work will involve searching the crater area for hot springs and possible associated biological communities, and mapping the lava flows as a means for understanding how such submarine volcanoes are constructed and how they grow to become ocean islands.

The origin of the Samoa island chain has long been debated among geochemists and other earth scientists. Some argue that the islands have followed a classic hot spot track, like the Hawaiian islands. Others argue instead that the origin is related to rifting or crustal plate activity associated with the northern terminus or end point of the Tonga Trench, based on the presence of active young volcanos along the chain from Savai’i to Ta’u. Harts says the discovery of Vailulu’u Volcano, well to the east of any possible influence from the Tonga Trench, and therefore the newest of the Samoan volcanoes, supports a hot spot model for the Samoan chain. "Just as Loihi is the newest volcano in the Hawaiian chain," he notes, "Vailulu’u is the Samoan equivalent of Loihi."

First discovered in 1975 by Rockne Johnson and named Rockne Volcano, this seamount was the site of a swarm of sizable earthquakes in January 1995, perhaps signaling the beginning of its current eruptive cycle. Prompted by this earthquake swarm, Hart and Staudigel mapped and sampled the seamount in March 1999. Unaware at the time of the 1975 discovery by Johnson, they informally named the seamount Fa’afafine Volcano.

The school children of American Samoa recently held a contest to pick a more lasting name. The winning entry, Vailulu’u, was submitted by Taulealo Vaofusi from Samoa High School, and announced during the 100th year Flag Day celebration on April 21, 2000. Vailulu’u is the sacred sprinkling of rain that reportedly always fell as a blessing just before a gathering of the great King Tuimanu’a, an icon of Samoan cultural life.

"Officially naming Vailulu’u at the 100th Flag Day celebration," Hart adds, "welcomed the, as yet unborn, newest island to the culturally rich Samoan archipelago."

##

Related Link: 3D Rendering of Vailulu'u Volcano: http://www-pacer.ucsd.edu/avon/samoanHS2.htm


Story Source:

The above story is based on materials provided by Woods Hole Oceanographic Institution. Note: Materials may be edited for content and length.


Cite This Page:

Woods Hole Oceanographic Institution. "Scientists Find Active Underwater Volcano East Of Samoa." ScienceDaily. ScienceDaily, 23 May 2000. <www.sciencedaily.com/releases/2000/05/000522082652.htm>.
Woods Hole Oceanographic Institution. (2000, May 23). Scientists Find Active Underwater Volcano East Of Samoa. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2000/05/000522082652.htm
Woods Hole Oceanographic Institution. "Scientists Find Active Underwater Volcano East Of Samoa." ScienceDaily. www.sciencedaily.com/releases/2000/05/000522082652.htm (accessed July 23, 2014).

Share This




More Earth & Climate News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 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:
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