Red Dye # 2.
Posted on 05/29/2006 9:25:06 AM PDT by NormsRevenge
WELLINGTON, New Zealand - A lake atop a rumbling volcano on the South Pacific island of Ambae has changed color from blue to bright red, puzzling scientists.
Mount Manaro, one of four active volcanos on the island nation of Vanuatu, has been showing signs of erupting for only the second time in 122 years.
"We are still ... trying to understand this change of color in the lake from blue to red," Geology and Mines Department director Esline Garae said by telephone Monday from Vanuatu's capital, Port Vila.
She said two scientists on Ambae Island were monitoring Lake Vui as well as seismic activity on the 5,000-foot Mount Manaro.
If the change of color "comes from new activity in the ground or just chemical change in the lake — these are two things I want to know from those guys before I can say anything" about the danger posed by the volcano, she said.
Mount Manaro last erupted in November 2005, forcing half the island's 10,000 inhabitants to evacuate their villages. An 1884 eruption killed scores of villagers.
New Zealand volcanologist Brad Scott said Lake Vui's color was "quite a spectacular red," but what had caused it "is the $64,000-question."
He said water samples from the lake would help determine what was happening in the crater and below it.
The color change could be a chemical process or gas from molten volcanic rock or something else coming into the lake, he said.
Three other volcanos in Vanuatu — Lopevi, Yasur and a two-crater volcano on Ambryn Island called Marum and Benbow — have spewed rocks, ash, smoke and steam in recent weeks.
Vanuatu, formerly the New Hebrides Islands, is made up of 13 main islands located about 1,400 miles east of Australia.
The subduction zone is further east, in the Idaho/Nevada corridor (the Great Basin region). Like around where Reno is. Some of the massive basalt flows in that region are only maybe a thousand years old, and they fully expect the ground to split open and lava to come pouring out in this region again within the next thousand years. The mountain west, particularly in Idaho/Nevada, is littered with active volcanic features like sulfur and steam vents. If you wander the mountains out there, you run across them all the time.
Nevada has some of the thinnest crust found on the continents, hence why much of the ground water is heated. Unlike further west, you do not really get volcanoes. Instead, you get massive cracks in the earth where lava pours out and thousands of cinder cones.
Red Dye # 2.
It's not you. Check out this link - and you can see where the "ring of fire" is located. It's all the countries which border the Pacific Ocean (from the west coast of America - Alaska - Australia, etc.:
USGS Earthquakes:
http://earthquake.usgs.gov/eqcenter/recenteqsww/
The USGS may also have links for volcanos - I just don't happen to have them.
Stop throwing the native virgin girls in it.
Ah, you recognize correctly.
Yet it falls to us to Saaaaaave the Plaaaaanet!! You see, it's being destroyed by SUV's!!
/s
Makes me wonder how fast a mountain could grow....interesting.
I thought that the Great Basin was an area of thin crust and spreading (Reno and Salt Lake City are moving apart) with cracks appearing as the crust is segmented. It is said that someday the Great Basin might become a sea interspersed with Islands as the ocean encroaches from the Gulf of California.
The true subduction zones are off the Coasts of Oregon, Washington and the Aleutian Islands happily feeding magma to the Cascade and Aleutian Volcanoes.
It doesn't work that way. That would be in the middle of the North American Plate. The geological features you are talking about are not caused by subduction.
The forces behind that are tremendous.
Ah, you recognize correctly.
And consequently if it's all George Bush's fault,
the power of the Rove must be stupendous!!
There's been no increase in volcanic activity around the world, nor is there any increase in earthquake activity (the number of large earthquakes worldwide is running below the 100-year average for what I believe is now the 6th or 7th year in a row.)
Tthere's just something called the internet where obscure news from around the world is more avaliable and a place called FR where such reports are easily avaliable in one place, accompanied by more interest in things geological since the 2004 tsunami.
Go take a look at a site like the Smithsonian Volcanism program http://www.volcano.si.edu/ and just surf around the world looking at the eruptive record of volcanoes - you'll find infinite numbers of eruptions from just, say, the 70s and 80s you never heard a thing about at the time, some quite large.
And your question is answered directly here:
http://www.volcano.si.edu/faq/index.cfm?faq=06
And if you examine a listing of all known Volcano Explosivity Index 4 or higher eruptions (all of those about 1/10th the size of Mt. St. Helens in 1980 or larger - good size eruptions) in the last 12,000 years, you'll see no increase in those and in fact a real absence of them recently. In the last 4 years there MAY be only one (Manam in New Guinea in 2005) an eruption that likely needs more study to assess its size.
Guh, you are correct. The Great Basin is a rift zone just east of the subduction zone.
My confusion is that I have read some geology articles that speculate on relationships between those formations. The coastal mountains of California are from the subduction zone, the Sierra Nevada are probably an artifact of the rift formation.
The Great Basin may become a sea one day, but it will have to lose almost a mile of elevation. Or get very wet.
Well at one time (tens of millions of years ago) there is some theorizing among geologists that the Farallon plate subducted below north America, but didn't dive into the Mantle, and instead slid along horizontally for hundreds of miles just under the North American plate, contributing to the creation of the Rockies some distance inland like someone pushing a rug along so it bunches up.
That story was in a weekly reader from the 50's or 60's I read years ago.
There is no subduction East of the Sierra crest (which forms the Western boundary of the Great Basin) rather the Pacific and North American Plates pass each other in a right-lateral fault (San Andreas) with the Pacific Plate moving generally in a NW direction. This is not the type of plate boundary known for volcanism but can spawn great earthquakes.
The Owens Valley East of the Sierra crest is sinking and filling with sediment while periodic great quakes (See Lone Pine 1872 earthquake) thrust the Sierra Crest upward. As throughout the Basin and Range the ranges bracketing the basin (Owens Valley) have have faults running parallel to their bases.
Is it me or does a lake that sits atop boiling, red hot lava turning from blue to red really not seem that puzzling?
Are these the same scientists that are stunned by research that everyone acknowledges as stipulated fact (i.e., "Research shows that 9 of 10 hetero men like boobies")?
Seriesly.
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