'Wired' Underwater Volcano May Be Erupting Off Oregon
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 Axial Seamount, an undersea volcano located 300 miles (480 kilometers) off the coast of Oregon, appears to be erupting.Credit: Bill Chadwick, Oregon State University |
An underwater volcano off the coast of Oregon has risen from its slumber and may be spewing out lava about a mile beneath the sea.
Researchers were alerted to the possible submarine eruption of the Axial Seamount, located about 300 miles (480 kilometers) off the West Coast, by large changes in the seafloor elevation and an increase in the number of tiny earthquakes on April 24.
Geologists Bill Chadwick, of the Pacific Marine Environmental Laboratory and Oregon State University, and Scott Nooner, of the University of North Carolina, Wilmington, successfully forecast the eruption in a blog post in September 2014, though they had presented their ideas at a meeting before then. [Axial Seamount: Images of an Erupting Undersea Volcano]
Axial Seamount is an underwater mountain that juts up 3,000 feet (900 meters) from the ocean floor, and is part of a string of volcanoes that straddle the Juan de Fuca Ridge, a tectonic-plate boundary where the seafloor is spreading apart.
Chadwick and Nooner have been monitoring the seamount for the past 15 years by measuring tiny movements in the seafloor as the volcano inflates with magma and then deflates. During that period, the volcano has erupted two other times — once in 1998 and again in 2011.
"It's kind of like a balloon — as magma is going into the balloon, it's inflating, and it pushes the seafloor up," Chadwick told Live Science. "As more and more magma gets in, the pressure builds. Eventually, it reaches some critical pressure where [the seamount] can't hold it in anymore, and then it squirts out."
After the volcano erupts, the seafloor drops very rapidly, "like letting air out of a balloon," he said.
World's first 'wired volcano'
For the first time, Chadwick and his colleagues were able to observe the eruption in real time, thanks to a set of instruments connected to shore by a fiber-optic cable, installed last summer by the University of Washington and paid for by the National Science Foundation.
"This is the first place in the world where we have a wired volcano on the seafloor," Chadwick said.
Last week, the center of the volcanic crater dropped by nearly 8 feet (2.4 m) over a period of 12 hours, and the number of tiny earthquakes increased from hundreds per day to thousands per day, Chadwick said. On April 24, there were 8,000 earthquakes in one day, he said. (The earthquakes are too small to cause any harm to coastal residents or to trigger a tsunami, the researchers noted.)
The measurements came from eight seismometers installed around the edge of the Axial Seamount's large caldera, as well as sensors that measure changes in water pressure as the volcano's surface inflates or deflates.
"If the seafloor is going up, there's less ocean above you, so there's a little less pressure," Chadwick said. "It's not much, but our instruments are so sensitive [that] we can measure to within a millimeter of vertical motion."
Ongoing rumblings
The seamount last erupted in April 2011. Scientists discovered the eruption by accident, on a routine expedition to the seamount in late July. They were planning to retrieve some instruments they had left there the year before, when a robotic vehicle sent down to explore the site revealed a fresh lava flow that was more than 12 feet (4 m) thick in places.
Nooner and Chadwick have been monitoring the Axial Seamount since its previous eruption in 1998. At the time, they forecast the seamount was due for another eruption at some point before 2016.
Chadwick and Nooner plan to return to the seamount this summer by ship, to confirm that an eruption occurred (Nooner said it would probably finish erupting before then), and to retrieve data stored on instruments that aren't connected to the cable observatory.
"The goal is to understand the basic behavior of volcanoes, because we really don't understand how magma chambers work and how magma works its way up through the crust," Nooner told Live Science.
In addition to the volcano, the site is home to hydrothermal vents and an entire biological ecosystem, which many different scientists are studying.
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Bulusan Volcano ejects steam and ash
By: InterAksyon.comMay 1, 2015 2:18 PM
InterAksyon.com
The online news portal of TV5
MANILA - The Philippine Institute of Volcanology and Seismology (Phivolcs), in its 1:30 p.m. advisory Friday, disclosed that Bulusan Volcano (12.7667°N, 124.0500°E) situated in Sorsogon Province, produced a steam and ash explosion which lasted for 5 minutes based on seismic records.
The volcanic activity was recorded at 8:09 a.m., although it may not have been observed visually due to thick rain clouds covering the summit.
"At around 10:30 a.m., when the crater became visible, strong to moderate, dirty white steaming was observed, reaching 200 meters high and drifting west-northwest coming from the northwest vent of the volcano," Phivolcs said.
Only five (5) volcanic earthquakes were detected during the past week by the Bulusan seismic network, but after the steam and ash explosion, the network recorded approximately 40 volcanic earthquakes.
Alert Level 0 status currently prevails over Bulusan Volcano, Phivolcs added.
However, local government units and the public are reminded that entry to the 4-kilometer radius Permanent Danger Zone (PDZ) remains strictly prohibited due to the possibility of sudden and hazardous steam-driven or phreatic eruptions.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano's summit as ejecta from any sudden phreatic eruption can be hazardous to aircraft.
"Furthermore, people living within valleys and along river/stream channels should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall," Phivolcs underscored.
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Huge lava lake overflows at Hawaii Kilauea volcano
1 May 2015 Last updated at 12:03 BST
Take a look at these amazing new pictures of the giant lava lake overflowing at the Kilauea volcano in Hawaii.
The lava has overflown several times since last Tuesday according to American geologists.
Lots of people have gathered to watch the volcano, from a safe viewing point nearby.
The volcano has been erupting for 31 years now, but in June last year a new vent opened up causing more lava to flow than usual.
The people who living in nearby towns and villages had to be evacuated from their homes late last year.
https://www.youtube.com/watch?v=cuUkrtQ67I0
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http://www.nytimes.com/aponline/2015/04/30/world/americas/ap-lt-chile-volcano.html
http://www.cnn.com/2015/04/30/world/chile-calbuco-volcano/index.html
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