Sunday, May 31, 2009
Discovery lead to historic volcanic eruption
Because the lava appears today as a distinctive layer of igneous rock containing easily datable fossilised marine life, the scientists were able to pinpoint the timing of the blast.
The fossilised rock shows mass extinction of different life forms, clearly linking the onset of the eruption with an environmental catastrophe.
The collision of fast-flowing lava with shallow sea water caused a violent explosion – throwing huge quantities of sulphur dioxide into the stratosphere.
"When fast-flowing, low-viscosity magma meets shallow sea it's like throwing water into a chip pan – there's a spectacular explosion producing gigantic clouds of steam," said Prof Paul Wignall, a palaeontologist at the University of Leeds, and the lead author of the paper.
The injection of sulphur dioxide into the atmosphere would have led to massive cloud formation spreading around the world – cooling the planet and ultimately resulting in acid rain. Scientists estimate from the fossil record that the disaster happened at the start of the eruption.
"The abrupt extinction of marine life we see in the fossil record firmly links giant volcanic eruptions with global environmental catastrophe," said Prof Wignall.
The work was done in collaboration with the Chinese University of Geosciences in Wuhan and funded by the Natural Environment Research Council, UK.
Sunday, May 24, 2009
Is there a possible volcanic eruption in store for Yellowstone Park?
A swarm of earthquakes is one sign that an eruption may be brewing and last winter Yellowstone National Park was rocked by a rash of tremors.
"There were over a thousand earthquakes in about one week," said Park Geologist Hank Heasler. "That isn't unprecedented in the parks history, but it is unusual."
"It was one of the largest swarms in the past 20 years," said USGS Volcanologist Dr. Jake Lowenstern. "It certainly got a lot of people's attention, including ours."
The entire park that exists today is the caldera of the last major eruption 240,000 years ago and experts say that eruption was destructive on a scale like we have never seen before.
"This put out about a thousand times more volcanic material than Mount St. Helens," said Heasler. "To put that in perspective, it's the difference between spending $1,000 and $1,000,000.
That eruption in 1980 in Washington was the deadliest and most destructive volcanic event in the nation's history. 57 people lost their lives in the eruption and volcanic ash was scattered across 12 surrounding states. But experts say another major eruption at Yellowstone would be much more deadly and destructive.
But how will we know if another big eruption is brewing? Dr. Jake Lowenstern is a member of the Yellowstone Volcano Observatory which is in charge of monitoring the park's supervolcano. The partnership between Yellowstone National Park, the US Geological Survey, and the University of Utah uses seismograph and ground deformation sensors to keep an eye on what is happening deep underground. Based on their research of the Yellowstone hotspot, the Observatory says another eruption is likely and may even happen in our lifetime. But fortunately for tourists and those living nearby, they say it won't be the big one.
"In a worse case scenario, the big super eruption, is very destructive and would cause a world of hurt to anybody living in the region around Yellowstone and surrounding states," said Lowenstern. "However, the big eruption is not what's most likely to happen here if we do get a volcanic eruption. Much more likely is some localized lava flows that will have an affect within the park. People will need to move out of the way. There will be fires. But people living hundreds of miles away, or even tens of miles outside the park are very unlikely to be affected."
"We have a very sophisticated monitoring system that will give us advanced warning if anything does start to occur," said Heasler. "So the best thing to do is come to the park and enjoy the beauty."
Chile: Danger ruled out by experts despite volcanic activity
According to Radio Cooperativa, the official stated that the smoke columns being emitted by the mountain are within normal range for the volcano’s activity level.
Nevertheless, volcanologists belonging to the National Geology and Mining Service (SERNAGEOMIN) –the organization in charge of monitoring activity levels of the nation's volcanoes–, will travel to the area today.
The Descabezado Grande volcano is located in the San Clemente mountain range and has a height of 3,830 meters.
Mount Vesuvius in action!
Well, is it time? With all the pompous weight of scientific certainty, I can now say…uh, maybe. It is instructive to look at the recent history of eruptions for a clue. “Recent” is relative. We can take the last 400 years or so because in geologic terms that is but a heart-beat.
Working back from the present, the last eruption of Vesuvius was in March of 1944. It happened in full view of the Allied armies, which had taken the city of Naples a few months earlier. WWII was still raging further north in Italy when Vesuvius went into what is called an “effusive” eruption (less violent than an “explosive” eruption, but nevertheless dangerous and potentially deadly). That eruption destroyed a number of nearby towns and a U.S. B-25 bomber group parked at the Capodichino airport in Naples. (The volcanic ash rendered the planes useless.)
Eruptions count as major or minor (and everything in between) depending on the extent to which they are explosive or effusive, how much ejecta they produce and the extent to which they change the profile of the volcano, blowing bits and pieces away, adding new craters, new lava flows, etc. Thus, the earlier eruptions of 1929 and 1926 were minor, but they did, for example, add a few new craters and damage nearby structures.
The eruption of April, 1906, was massive and attracted worldwide attention. It killed 100 persons and buried nearby towns. The initial rumblings, however, caused little alarm and locals joked that “the mountain” was just preparing a royal welcome for British King Edward, due in Naples for a visit shortly. He made it just in time for an eruption that dropped the ridge on the main cone some 250 meters. The eruption covered the city of Naples, itself, with ash, and made the roads near the volcano impassable. Residents of destroyed villages fled to Naples, itself, or to nearby towns such as Castellammare. The eruption was followed by heavy rains that produced what geologists now call a lahar (an Indonesian word)—massive mud and ash slides that buried everything in their path. (Some sources reported at the time that it was the most massive eruption since the great explosion that destroyed Pompeii and Herculaneum in 79 AD. That may be an exaggeration, since the 1872 and the 1631 eruptions were likely to have been at least as powerful.)
The year 1872 produced a massive eruption classified as “explosive/effusive.” It had been preceeded by minor eruptive activity in 1861, 1858, 1855, 1831 and 1824. That time frame spans the foundation of the geological observatory, itself, on the slopes, in 1841. The institution was the brain-child of Macedonio Melloni (1798-1854), who became the first director. It survived the political upheavals that came with the conquest of the Kingdom of Naples and its absorption into the modern nation state of Italy. The directorship then passed to Luigi Palmieri (1807-96), who was on duty constantly during the 1872 eruption. You can see the observatory today and from a distance notice that it sits on a handy knoll with the lava flow of the ‘72 eruption going around it! There were scientific heroics as the director, Prof. Palmieri, refused to leave so he could man the instruments. Palmieri was totally cut-off and alone, but he survived.
A major eruption occurred in 1807; in the 1700s, there were two notable eruptions, 1794 and 1737, both of which destroyed local villages. The 1794 eruption opened crates at relatively low levels on the slopes—at 480 and 320 meters. (The current height of Mt. Vesuvius is 1280 meters.)
The modern cycle of eruptions of Mt. Vesuvius started on Dec. 16, 1631 with an eruption classified as “explosive” (as opposed to the less violent “effusive” or “explosive/effusive”). The volcano had been quiet for some centuries and then simply blew its top. Most sources cite this eruption as the “greatest since Pompeii.” It followed the familiar behavior of an exploding volcano: lava fountains as high as 4 km and an ash column as high as 15 km, which then collapsed onto the slopes producing what is now called a “pyroclastic flow.” It was followed in 1637, ’49, ’52, ’54, and ’60 by lesser eruptions. Some of those were accompanied by earthquakes; indeed, even the dreaded bubonic plague showed up in 1656, lending credence amongst believers to the rumor that the world was coming to an end. It didn’t, of course, and it won’t after the next one. (Uh, I didn’t say that aloud, did I?)
Ecuador: Volcano becomes active after 4 years!
After four years of inactivity, Galapagos Islands' La Cumbre Volcano spewed lava, gas and smoke on Saturday on Fernandina Island. La Cumbre has an elevation of 4,842 feet.
According to the Geophysical Institute of the National Polytechnic School it has recorded 43 thermal alerts. The institute's satellite images showed a column of gas 60 miles long west of the Galapagos Island. This indicates an increase in volcanic activity.
Fernandina, although uninhabited, is the most active island in the Galapagos archipelago. According to the Galapagos National Park, an eruption will not likely affect residents of the nearby Isabela Island, but it may affect the Galapagos' animal life.
The UNESCO declared in 1978 Galapagos as a World Heritage Site. Charles Darwin formulated his theory of evolution after he studied Galapagos' animal population. Since then, biologists, conservationists and tourists have been attracted to the islands. The Galapagos National Park said 41,000 tourists visited the islands for the first trimester of 2009.
Residents told not to panic as volcano spews ash
Coastal residents living close to Mount Anak Krakatau, off the Sunda Strait in Lampung, have evacuated to Bandarlampung out of fear of an imminent eruption of the volcano due to increased volcanic activity, despite the fact that its alert status remains at two, our of four.
Sonhaji, 45, a resident of Bawang village, Punduh Pidada district in South Lampung, said he took his family to his relative’s house in Bandarlampung on April 18, as he was afraid Mount Anak Krakatau would have a major eruption, as it has been producing small eruptions over the past week.
“The distance between our village and Anak Krakatau is more than three miles, but the sound of eruption that it produces is very loud, like the sound of a cannon in the middle of the sea,” he said.
“So far it has never emitted such loud blasts and we have been observing that it has often discharged molten lava.”
Sonhaji said fishermen had been afraid to fish around the volcano and the Sunda Strait over the past week.
Residents in Punduh Pidada say they have not heard eruptions as huge as those over the past week since Anak Krakatau was classified as active.
South Lampung Regent Wendy Melfa said his office is coordinating with the Natural Disaster Mitigation Agency in anticipation of the possibility of an eruption.
“The status of the volcano remains alert as of now, but we are helping people to evacuate because they are terrified,” Wendy said.
“We have also informed islanders around the volcano not to panic.”
The Vulcanology and Geological Disaster Mitigation Center (PVMBG) in Bandung has set the status of the volcano, situated east in the Sunda Strait, as alert. The last time it showed signs of activity was in mid February, when it erupted up to three times a day.
The seismograph at the Anak Krakatau observation post in Hargopancuran village, Rajabasa district, South Lampung, has recorded 126 eruptions weekly, including 23 deep underground, 82 shallow and 149 hot cloud discharges.
In Bandung, chief of the center’s volcano monitoring team, Muhammad Hendrasto, called on residents not to panic.
“Its activities have yet to increase the current alert level,” he said.
Visual observation from the Pasauran post in Cinangka district, Serang regency in Banten shows greyish ash formations between 200 an 800 meters high.
The formation is monitored by the MITSAT satellite of the Australian Bureau of Meteorology. Qantas pilots have also reported the ash formations.
Mount Redoubt is a Media celebrity!
Photographers are waiting for the few days when clouds don't obscure the volcano, which began erupting last month.
Clouds gave way on Friday, allowing the entire volcano to be visible for an extended period of time.
That attracted numerous people to flock to pullout points near the volcano - at Kalifornsky Beach Road, Bridge Access Road and the Spur Highway - to snap photos of Mount Redoubt.
Once Pat Porter of Kenai saw the clear view of Mount Redoubt, she turned around and went back to her home to get a camera.
"I've been here for more than 30 years, and I remember the last eruption, but I didn't get any photos. This time around, today was the first time I've been able to get to a camera and get back while it was still out. I wanted to take a few pictures, just to have them," she told the Peninsula Clarion.
Lyle Skrimger of Kenai also was compelled to take photos since the eruption is a rare occurrence.
"It only happens every 20 years, so I wanted to get a few. If I get one worth keeping, I may put it up in the house," he said.
Christine Armond of Kenai, who recently moved from the Midwest, had never seen Mount Redoubt or any other volcano erupt. She wants to share photos of the event with friends and family in the Lower 48.
"You just don't even see mountains back where I'm from, much less a snow-covered volcano giving off steam and ash, so my family and friends back in Oklahoma really love seeing this stuff," she said.
Others had more pressing reasons to shoot the volcano, like Jessica Gonzalez of Niksiki.
She's hoping for a good grade after being assigned a project for a photography class at Kenai Peninsula College.
"It's homework," Gonzalez said, but added that as homework goes - staring at the steaming volcano in the warm rays of the sun and in the soft breeze - it was a pretty enjoyable assignment.
