Sunday, December 25, 2011

GLOBAL VOLCANISM: America's Ten Most Dangerous Volcanoes - Geological History and Possibilities for Future Eruptions!

Here's a look at the ten most dangerous volcanoes in America. Geologists classify volcanoes into three distinct groups: dormant, extinct, and active. Active volcanoes have erupted recently and are expected to continue to erupt again soon. The Smithsonian Global Volcanism Program defines an active volcano as having erupted within the last 10,000 years. A volcano finally goes extinct when there's no lava supply in the magma chamber beneath the volcano.

1. Kilauea Volcano, Hawaii.

A photographer slinks into the Pu'u 'O'o crater of Hawaii's Kilauea volcano, which has been active since 1983. "A lot of the time the lava's flowing into the sea, and you can walk right up to it," said the USGS's Eichelberger. One of Kilauea's hazards includes the potential for explosive eruptions. "That's when the magma comes flying out as blocks or particles of ash instead of flowing out intact as lava," Eichelberger explained. What volcanologists call explosive activity varies. "Sometimes they're discrete explosions ... and things go flying all over the place. Other times it's more like a spray from a fire hose," he said. As a general rule, "it's wise not to be close to an explosive eruption."

2. Mount St. Helens Volcano, Washington.

The eruption of Mount St. Helens 30 years ago on May 18, 1980 (pictured),  is the most devastating and most studied volcanic explosion in U.S. history. The blast killed 57 people and spewed 520 million tons of volcanic ash, darkening the skies of Spokane, Washington, more than 250 miles (400 kilometers) away. Over the last 10,000 years, Mount St. Helens has erupted more frequently than any other volcano in the Cascade Range, and has continued erupting, albeit gently, in recent years. "Certainly it's not possible to replicate the 1980 eruption, because the mountain isn't there anymore—it collapsed," said USGS Volcano Hazards Program coordinator Eichelberger. "But there's nothing to say that a new, very gas-rich batch of magma couldn't come in under the thing and start a new explosive cycle."

3. Mount Rainier Volcano, Washington.

The danger with Washington State's Mount Rainier is that it's covered by more snow and ice than all the other Cascade Range volcanoes combined, so it presents a high risk of lahars, or volcanic mudflows. "A lahar is like concrete flowing down the chute of cement mixer," said the Cascades Volcano Observatory's Scott. In the past Mount Rainier's lahars have run down the river valley all the way to Puget Sound, a distance of more than 62 miles (100 kilometers). "That's where a lot of the [urban] development is. so that's a key hazard," Scott said. Mount Rainier undergoes significant volcanic activity every 500 to 1,000 years, Scott said—and the volcano's last big explosion was about 500 years ago. "But right now we know the volcano is at rest."

4. Mount Hood Volcano, Oregon.

Climbers cross a ridge on Oregon's most dangerous volcano, Mount Hood. "A key issue with Mount Hood is that people live on the flank of the volcano, state highways cross its flanks—so there's a lot of stuff up close," the Cascade Volcano Observatory's Scott said. Mount Hood was very active at the end of the last ice age, and there have been two significant eruptions in the last 1,500 years—the last of which happened just before Lewis and Clark came through in the early 1800s. One interpretation of Mount Hood's volcanic activity is that the mountain has recently ended a long period of dormancy and "in the future it might be erupting on the order of every few centuries," Scott said.

5. Mount Shasta Volcano, California.

Flanked by an interstate, California's Mount Shasta volcano looms over thousands of homes, a key to its USGS "very high threat" rating. Around Mount Shasta an eruption's pyroclastic flow—rapid currents of superheated gas, ash, and rock caused by a volcanic explosion—as well as ash-infused mudflows could put towns and infrastructure in harm's way. The last reported eruption was seen from the Pacific Ocean in 1786 and may not have "been such a big deal," the Cascades Volcano Observatory's Scott. "We haven't had [an eruption] since settlement by European settlers, but in the geologic sense the volcano has been quite frequently active."

6. South Sister Volcano, Oregon.

With South Sister (pictured) ranked by the USGS as a "very high threat" volcano, the Three Sisters area is a volcanic hotbed spanning about 115 square miles (300 square kilometers) just west of Bend, Oregon. The next major activity in the area might not be an eruption of one of the three volcanic peaks—Middle, South, and North Sister—but the start of a new volcano altogether, the Cascades Volcano Observatory's Scott said. "It could really occur almost anywhere in that broad area." In the late 1990s and early 2000s, an area of ground west of the Middle and South Sister started to deform. Volcanologists closely monitored the 9-mile-wide (15-kilometer-wide) area they dubbed "the Bulge," since ground deformation can indicate magma moving and accumulating underground. The Bulge, though, is now deflating. "In the end, it didn't result in an eruption," Scott said. "But it may be evidence of a process that may eventually produce one."

7. Lassen Volcanic Center, California.

It might be slightly unfair to single out Lassen Peak (pictured), since the Redding, California-area volcano (map) is simply one among several volcanoes in a volatile cluster. "The next eruption might not be on Lassen Peak," said the Cascades Volcano Observatory's Scott. The blast could take place at a neighboring volcano—or create a new one altogether. Lassen Peak last erupted during between 1915 and 1917. Like Mount St. Helens 30 years ago, the California volcano blew down a patch of forest, but on a much smaller scale. The previous eruption in the area—called the Lassen Volcanic Center—in the mid-17th century formed a new volcanic cone about 10 miles (16 kilometers) east of Lassen Peak.

8. Mauna Loa Volcano, Hawaii.

The largest volcano on Earth, Hawaii's Mauna Loa has erupted 33 times since its first documented eruption in 1843, but has been relatively quiet since 1984. Mauna Loa's general ooziness is due largely to the fact that "the Pacific crust is sinking down below the continents," the USGS's Eichelberger said. "That introduces a lot of water into the hot area of the mantle, which causes melting—and then you get volcanoes." The molten rock is less dense than solid rock, so it tends to rise to the surface, as at Mauna Loa, where lava constantly flows into a beleaguered nearby community.

9. Redoubt Volcano, Alaska.

Alaska's Redoubt Volcano, which last erupted in 2009 (pictures), presents a high risk because of its proximity to the city of Anchorage, its international airport, and the flight paths overhead. Pictured on April 21, 1990, erupting Redoubt Volcano in 1989-90 sparked volcanic mudflows, or lahars, which swept into an inlet some 13.5 miles (35 kilometers) away. Ash from the volcano temporarily shut down a 747's engines in December 1989. Though the crew restarted the engines in midair, the incident's aftershocks can still be felt in recent on-again, off-again airport shutdowns related to Icelandic volcanic ash.

10. Crater Lake Volcano, Oregon.

A lava outcrop juts from the rim of Oregon's Crater Lake. Born of a blast that expelled more than 50 times the volume of magma as the Mount St. Helens eruption 30 years ago, this watery caldera is also the United States' tenth most dangerous volcano, according to the U.S. Geological Survey (USGS). Of the 169 geologically active volcanoes in the U.S, 54 volcanoes have USGS threat levels  of "high" or worse, based on perceived explosiveness and what's at risk near the volcano. Mother Nature, though, can reshuffle the ranking at any time. "A volcano can be quiet for a long time, and we would give it a low threat level," said John Eichelberger, coordinator of the USGS Volcano Hazards Program. "But it can surprise us." For instance the long-gone Mount Mazama volcano cluster staged quite a surprise when it exploded 7,700 years ago—the largest Cascade Range eruption of the last hundred thousand years. Water eventually filled the resulting three-mile-wide (eight-kilometer-wide) wide crater, forming Crater Lake. "You could look at that as a system that exhausted itself," said William Scott, a geologist at the USGS Cascades Volcano Observatory in Vancouver, Washington. "It’s been quiet for the last 5,000 years."

Read more on these volcanoes HERE.

According to the National Geographic, the world's "sleeping giants" volcanoes can wake up much quicker than thought.
Scientists believe the magma chambers—or reservoirs of molten rock—under dormant volcanoes are filled with sticky, viscous mush. For a volcano to "wake up," this mush needs to be thoroughly heated by fresh, hot magma rising up from the deep Earth. According to current theory, it would take several hundred or perhaps a thousand years for the heat to distribute through the chamber and make the magma fluid enough to erupt. But a new model based on fluid dynamics shows that hot, deep magma can mix with the older, sticky stuff much easier than believed, scientists say. "That's one reason that the rejuvenation can happen so quickly—the transport of hot material coming in [to the] magma system is much more efficient than we previously had understood," said study co-author George Bergantz, a geologist at the University of Washington.

The team compared their model with two real-life eruptions: the Philippines' Mount Pinatubo in 1991 and an ongoing eruption of the Soufrière Hills volcano in the British Caribbean territory of Montserrat. The scientists analyzed the two volcanoes' magma temperatures, chamber sizes, and other physical features to come up with rough time intervals between the first warning signs and the actual eruptions. In the case of Pinatubo, the team discovered that the magma chamber took only 20 to 80 days to reactivate, versus the 500 years predicted by conventional theory. - National Geographic.

FUK-U-SHIMA: Japan's Nuclear Dead Zone Spreading Far And Wide - Japan Atomic Energy Commission (AEC) Chairman Shunsuke Kondo Warn That People Living Within 170km of the Fukushima Nuclear Plant Might Need to Relocate!

The head of the government's nuclear energy panel warned in March that all residents in areas within a 170-kilometer radius of the crippled Fukushima nuclear plant might need to be relocated in a worst-case scenario, sources close to the government have disclosed.

Japan Atomic Energy Commission (AEC) Chairman Shunsuke Kondo made the warning in a report numbering about 20 pages, which he compiled on March 25 -- two weeks after the Fukushima No. 1 Nuclear Power Plant was hit by a massive tsunami generated by the Great East Japan Earthquake -- and submitted it to then Prime Minister Naoto Kan.

At the time, the plant had lost its reactor core cooling functions due to the loss of all external power, hydrogen explosions had ripped through the plant's No. 1, 3 and 4 reactor buildings, and radioactive substances were leaking from the No. 2 reactor due to a meltdown. Workers at the plant had no choice but to manually inject water into the reactors to cool down their cores.

Kondo assumed that in a worst-case scenario, another hydrogen explosion could occur in the No. 1, 2 or 3 reactor buildings, raising radiation levels. Continuing aftershocks would prevent workers from cooling down the reactors for an extended period and that all fuel in a pool for spent nuclear fuel in the No. 4 reactor building pool would melt. At the time, the pool held 1,535 fuel rods that could fill two nuclear reactors. - MDN.

GLOBAL VOLCANISM: Mount Sakurajima in Japan Continues its Explosive Eruptions - Breaking the Previous Annual Record for the Third Consecutive Year!

Mount Sakurajima
, an active volcano in Kagoshima Prefecture, continues its explosive eruptions on Christmas Eve.  Several days ago, the volcano had erupted for the 897th time this year, breaking its annual record for the third consecutive year, a local volcano observatory said.

The volcano has had a record number of explosive eruptions each year since 2009, when it erupted 548 times, beating the previous record of 474 set in 1985. In 2010, there were 896 eruptions. Observation of the volcano began in 1955. The latest eruption was observed at the 800-meter-high Showa crater, which has erupted 895 times this year. It has been a frequent site of activity since 2008, after erupting in June 2006 for the first time in 58 years. Iguchi Masato, associate professor at Kyoto University's Sakurajima Volcano Research Center, said the volcano could become extremely active in January or February, as eruptions since 2009 have tended to increase before New Year, and a new monthly record of 141 explosions was marked in September. 

WATCH: The latest closed-circuit images of Mount Sakurajima.

MASS FISH DIE-OFF: Four Tons of Dead Fish in Three Days in Ahmedabad, India - Authorities from the Health Ministry Rush to Nearby Pond to Unravel the Mystery?!

The fisheries, forest and health departments of Ahmedabad district swung into action on Friday after receiving reports of fish dying en masse in a pond near Kerala, a village located 38 km from Ahmedabad. According to sarpanch of the village, at least four tonnes of fish has died over the last three days.

Teams from these departments visited the pond, collected samples and asked villagers not to consume dead fish or draw water from the reservoir. “We noticed some dead fish, small and some weighing up to five kg, washed ashore on Wednesday night. The next morning, there were piles of them and it continued on Thursday and Friday,” sarpanch Subhas Thakar told The Indian Express.

The natural pond is right at the foot of the village with a population of around 7,000 and is spread over five acres. It is 30-feet deep at some points and fresh water remains round the year. Its banks are lined by a rice mill, a bearing factory and farms, the sarpanch said, adding fishing is not allowed there. “We informed authorities after problem seemed to grow serious on Thursday,” Thakor said. “Tat and wild fish are dying probably due to sudden drop in the oxygen level in water of the pond. Sometimes, the oxygen level goes down due to overcast condition and it is a short-term phenomenon. However, we will come to know the real cause only after tests are done and reports are filed,” Vallabh Rupani, in-charge assistant director at the fisheries department, Ahmedabad district, said.

A team of the department visited the site and was expected to file a report on Saturday, Rupani added. A team of health officials also visited the site on Thursday. “We have given written instructions to the Kerala sarpanch to tell villagers not to eat the fish being washed ashore. It can endanger their health,” Bavla Block Health Officer (BHO) Dr Alpesh Gangani said. However, the sarpanch said that despite the instructions, residents of surrounding villages collected dead fish, especially the larger ones, and sold them in Bavla.

Ahmedabad district health officer Dr NJ Patel said the situation was under control.A team of Gujarat Pollution Control Board (GPCB) also visited the pond and collected samples of water on Thursday. “We have collected samples from three different parts of the pond and after analysing the results of the sample tests, we would be able to know if there is contamination or any pollutants in the water,” C A Shah, GPCB Regional officer in Gandhinagar, said.

A team of Ahmedabad district forest officials also went to Kerala to take stock of the situation, District Forest Officer Raman Murhty said. The sarpanch said the phenomenon was unusual and government officials expressed fear that the effluent released by nearby industrial units might have contaminated waters and led to the death of fish. However, Rupani said overpopulation of fish could be a reason. “Tat and wild fish breed twice a year. On the other hand, in such ponds, panchayats do not allow fishing on religious grounds. This leads to overpopulation and sometimes to such phenomena. A similar incident had happened in a village in Mehasana in 2010,” he said. - Indian Express.

GLOBAL VOLCANISM: Ash From Chilean Volcano Craters Argentine Towns - Unpredictable Eruptions Leave a Pristine Patagonian Region Bereft of Its Tourism Lifeblood; Planes Grounded 7,200 Miles Away!

On a crystal-clear summer morning in this mountainous Patagonian resort, a lone paraglider floated gently above a placid lake shore. "You know, when the wind is blowing right, everything here is still perfect," said Marcelo Cascon, an ex-mayor here.

That perfection evaporated a little while later when the wind suddenly shifted, blowing a cloud of ash from Chile's Puyehue Volcano 55 miles to the west. Some pedestrians in this town, considered the Aspen of South America, covered their mouths with surgical masks or scarves. A thin granular film soon accumulated on windshields and shop windows.

Volcanic eruptions, continuing now for six months, have devastated this city of 130,000 and nearby Argentine communities, which are economically dependent on skiers in winter and fishermen and trekkers in summer. Regional airports have been paralyzed. Hotel bookings are way down and restaurants are largely empty. Several thousand residents have pulled up stakes in search of better prospects elsewhere.

Most troubling of all is the uncertainty over when the ordeal will end. "Your business plan depends upon which way the wind's blowing and what's happening inside of a volcano," said Claudio Roccatagliata, manager of the five-star Villa Huinid Resort and Spa. - Wall Street Journal.

WATCH: Lightning and ash as Chile volcano erupts.

WATCH: Lightning inside Chile Puyehue volcano ash cloud.

PLANETARY TREMORS: Seismic Swarms - Earthquakes Continue to Shake Up Christchurch, New Zealand!

Christchurch was still shaking on Christmas Eve, with seismologists logging several sizeable earthquakes overnight, hours after the shattered city in New Zealand was rocked by a swarm of massive tremors. 

• 07:39 UTC - 4.0 Magnitude - Depth 15 km - 10 km East of Christchurch
• 07:51 UTC - 3.5 Magnitude - Depth 8 km - 20 km Southeast of Christchurch
• 10:04 UTC - 3.5 Magnitude - Depth 10 km - 10 km East of Christchurch
• 15:44 UTC - 3.0 Magnitude - Depth 8 km - 10 km East of Christchurch
• 15:56 UTC - 3.3 Magnitude - Depth 9 km - 10 km East of Christchurch
• 16:14 UTC - 3.5 Magnitude - Depth 11 km - 20 km Northeast of Christchurch
• 16:22 UTC - 3.5 Magnitude - Depth 8 km - 10 km Northeast of Christchurch
• 16:26 UTC - 3.5 Magnitude - Depth 9 km - 10 km East of Christchurch
• 17:03 UTC - 3.3 Magnitude - Depth 6 km - 20 km Southeast of Christchurch
• 17:41 UTC - 3.7 Magnitude - Depth 8 km - 10 km East of Christchurch
• 18:15 UTC - 3.0 Magnitude - Depth 7 km - 20 km Northeast of Christchurch