©http://ottersandsciencenews.blogspot.ca/. Unauthorized duplication of this blog's material is prohibited. Excerpts and links may be used, provided that full credit and link is given to Otters and Science News Blogspot. Link to this post: http://ottersandsciencenews.blogspot.ca/2015/05/massive-underwater-volcano-erupting-300.html - Thank you for visiting my blog.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Is Axial Seamount erupting? Seafloor off the coast of Oregon has dropped 8 FEET due to movement in the 'wired' underwater volcano.
Last year, researchers connected monitoring equipment to an undersea cable that allowed them to gather live data on the volcano (location marked), whose peak is about 4,900 feet (1,500meters) below the ocean surface
Continue reading and see more images
AXIAL SEAMOUNT VOLCANO
- The Juan de Fuca Ridge is part of an ocean ridge system situated 300 miles (480km) off the coast of Oregon.
- Axial Seamount rises almost a 0.6 miles (one km) above this ridge.
- It is the latest in a series of large volcanoes built by movement over the earth’s crust over a deeper 'hot-spot' known as the Cobb-Eikelberg hotspot.
- It is situated in the mantle and is said to be the source of the extra magma supply.
- Geologists predicted the volcano would erupt this year during a public lecture in September.
- And for more than a week the region has experienced thousands of tiny earthquakes.
- The seafloor has also reportedly dropped by almost 8ft (2.4 metres).
- Researchers know of two previous eruptions by the volcano, but those 1998 and 2011 eruptions were detected after the event.
- Last year, researchers connected monitoring equipment to an undersea cable that, for the first time, allowed them to gather live data on the volcano, whose peak is about 4,900 feet (1,500 meters) below the ocean surface
Geologists predicted the volcano, called Axial Seamount (pictured), would erupt this year during a public lecture in September. And for more than a week the region has experienced thousands of tiny earthquakes (activity pictured) - a sign that magma is moving toward the surface.
UNDERWATER VOLCANO ERUPTIONS
- Geologists at the National Oceanic and Atmospheric Administration recently used robotic submarines to record underwater volcanic eruptions 3,937ft beneath the surface of the Pacific Ocean near Samoa.
- They found the acoustic signatures from two different types of eruption were distinct and can be used to identify underwater eruptions around the world.
- Rather than the explosive roar emitted by their cousins on land, underwater volcanoes give off a muted thrum instead.
- However, the research could allow scientists to monitor undersea volcanoes far more effectively than they have before.
The Juan de Fuca Ridge (pictured) is part of an ocean ridge system situated 300 miles (480km) off the coast of Oregon. Axial Seamount rises almost a 0.6 miles (one km) above this ridge.
The Daily Mail - An undersea volcano situated 300 miles (480 km) off the coast of Oregon is thought to be erupting after signs of magma were spotted near its deep sea vent.
Geologists predicted the volcano, called Axial Seamount, would erupt this year during a public lecture in September.
And for more than a week the region has experienced thousands of tiny earthquakes - a sign that magma is moving towards the surface.
The seafloor has also reportedly dropped by almost 8ft (2.4 metres), additionally said to be a sign of magma being withdrawn from a reservoir beneath the summit.
It is dubbed Axial Seamount due its location along the axis of an underwater mountain ridge.
The earthquakes were first recorded by William Wilcock from the University of Washington using instrumentation from the NSF-funded Ocean Observatories Initiative.
And the forecast was made by geologists Bill Chadwick of Oregon State University and Scott Nooner of the University of North Carolina Wilmington during a lecture last year, followed by a blog post.
They based their forecast on some of their previous research, funded by the National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA), which showed how the volcano inflates and deflates like a balloon in a repeatable pattern as it responds to magma being fed into the seamount.
'It isn't clear yet whether the earthquakes and deflation at Axial are related to a full-blown eruption, or if it is only a large intrusion of magma that hasn't quite reached the surface,' said Professor Chadwick, who works out of OSU's Hatfield Marine Science Center in Newport and is affiliated with NOAA's Pacific Marine Environmental Laboratory.
The earthquakes were recorded by William Wilcock from the University of Washington and the forecast was made by geologists Bill Chadwick of Oregon State University and Scott Nooner of the University of North Carolina Wilmington last year. The seafloor has also dropped by 8ft (2.4 metres) (Axial Seamount pictured)
Researchers know of two previous eruptions by the volcano, but those 1998 and 2011 eruptions were detected months or years afterward.
Last year, researchers connected monitoring equipment to an undersea cable that, for the first time, allowed them to gather live data on the volcano, whose peak is about 4,900 feet (1,500 meters) below the ocean surface.
This cable has led to the volcano being dubbed 'wired'.
'The cable allows us to have more sensors and monitoring instruments than ever before, and it's happening in real time,' said Professor Chadwick.
In the past, researchers left battery-operated monitoring stations in place for several years, but were able to analyse the data only by retrieving those devices.
Pressure sensors detected that an eruption was underway on April 23.
NSF/OOI/University of Washington
Instruments on the rim of the Axial Seamount
measure the movement of the sea floor
After monitoring hundreds then thousands of small earthquakes each day near Axial Seamount, they detected more than 8,000 tiny quakes over a 24-hour span on this day.
As midnight approached, pressure sensors detected the seafloor dropping - a sign that magma was erupting - and the swollen volcano was 'deflating like an emptying balloon'.
In total, the seafloor has dropped 8 feet (2.4 meters) in the past week.
Axial Seamount vent as seen in 2011.
Though the eruption has slowed, the volcano still seemed to be expelling magma as of last Friday, Professor Chadwick said, leaving his team wondering where the lava was going.
'We know it didn't erupt in the caldera, or crater, because that's where most of our sensors are, and they all survived,' he said.
Temperature fluctuations and seismic readings are consistent with an eruption north of the volcano's crater.
'But we probably won't know until this summer, when we get out there with a ship and are able to look around.'
In any case, the researchers say, such an eruption is not a threat to coastal residents.
The earthquakes at Axial Seamount are small and the seafloor movements gradual and thus cannot cause a tsunami.
Axial Seamount provides scientists with an ideal laboratory, not only because of its close proximity to the Northwest coast, but for its unique structure.
'Because Axial is on very thin ocean crust, its 'plumbing system' is simpler than at most volcanoes on land that are often complicated by other factors related to having a thicker crust,' continued Professor Chadwick.
'Thus Axial can give us insights into how volcano magma systems work - and how eruptions might be predicted.'
Image: PMEL Earth-Ocean Interactions Program/OOI Cable Array.
Geologists are scheduled to go back to Axial in August to gather more data, but it may be possible for other researchers to visit the seamount on an expedition as early as May.
They hope to confirm the eruption and, if so, measure the volume of lava involved.
Text
Pictures from Daily Mail, Nature, and Io9
Read more:
- Researchers think Axial Seamount off Northwest coast is erupting – right on schedule | News & Research Communications | Oregon State University
- Successful eruption forecast at Axial Seamount
More on volcanoes on this blog
*****************************************************************************
No comments:
Post a Comment
Thank you for visiting my blog. Your comments are always appreciated, but please do not include links.