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Big Bunny
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« Reply #45 on Apr 11, 2010, 12:13pm » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
11-APR-2010 09:40:29 -10.93 161.19 6.8 51.9 SOLOMON ISLANDS
http://www.iris.edu/seismon/
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #46 on Apr 11, 2010, 6:45pm » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
11-APR-2010 22:08:10 37.08 -3.47 6.2 616.7 SPAIN
http://www.iris.edu/seismon/
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #47 on Apr 13, 2010, 8:28pm » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
14-APR-2010 00:12:25 33.03 96.56 5.2 10.0 QINGHAI, CHINA
14-APR-2010 00:01:16 32.69 96.87 5.3 10.0 QINGHAI, CHINA
13-APR-2010 23:49:42 33.26 96.67 6.9 46.9 QINGHAI, CHINA
13-APR-2010 21:40:00 33.18 96.62 5.0 18.9 QINGHAI, CHINA
http://www.iris.edu/seismon/
Quake kills hundreds in north-west China
By China correspondent Stephen McDonell and wires
Updated 23 minutes ago
![[image]](http://img707.imageshack.us/img707/3581/r54862232327895691758.jpg "[image]")
The quake's epicentre was reportedly 380 kilometres south-east of the city of Golmud.
A powerful earthquake in north-west China has reportedly killed 300 people and left others trapped under rubble.
The earthquake measuring 6.9 struck the remote Qinghai Province. The epicentre was reportedly 380 kilometres south-east of the city of Golmud.
At least some of the deaths have occurred in the ethnic Tibetan town of Yushu.
The death toll is expected to rise rapidly as people are pulled out of collapsed houses.
Qinghai is an isolated mountainous province in the west of China and at one point formed part of greater Tibet.
It has a large ethnic Tibetan population and is the home of the Dalai Lama.
Troops have been dispatched to the area.
Residents without shelter
Many residents of the remote Yushu region could be without shelter following the quake, in temperatures that hover near freezing and even colder in the high mountain villages.
"Certainly there have been people hurt. Rescuers are trying to pull them out," resident Talen Tashi said.
"A lot of one-storey houses have collapsed. Taller buildings have held up, but there are big cracks in them."
People from the Yushu prefecture highway department were frantically trying to dig out colleagues trapped in a collapsed building, department official Ji Guodong said.
Most of the low residential buildings had fallen, Huang Limin, a government official in Yushu told state television.
"Casualties are unclear. Maybe dozens were injured, maybe more. It's hard to say," said Zhuo De, an ethnic Tibetan resident of Yushu, who spoke by phone from the capital of Qinghai province after contacting his family in Yushu.
"The homes are built with thick walls and are strong, but if they collapsed they could hurt many people inside."
A magnitude 5.0 quake struck the same region late on Tuesday night, and aftershocks of magnitude 6 and over rattled the town this morning, sending fearful residents into the streets.
The Tibetan plateau is regularly shaken by earthquakes, but casualties are usually minimal because so few people live there.
Movement of the Indian subcontinent toward the Himalayas has thrust up the plateau, triggering quakes in the foothills including the magnitude 8 quake that hit Sichuan province in May 2008, killing 80,000 people.
http://www.abc.net.au/news/stories/2010/04/14/2872246.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #48 on Apr 15, 2010, 10:21am » | |
Volcanic ash grounds flights worldwide
9 News
![[image]](http://img408.imageshack.us/img408/8282/307740icelandvolcano501.jpg "[image]")
Smoke and steam rises from the volcano under the Eyjafjallajokull glacier in Iceland have grounded hundreds of flights across Europe / AP ( http://www.news.com.au/travel/news/thous....0-1225854313492 )
Iceland's second volcano eruption in a month has melted part of a glacier and caused heavy flooding.
Hundreds of flights worldwide were cancelled or delayed as volcanic ash from Iceland swept across northern Europe, closing airspace above Britain, Ireland, Scandinavia and other countries.
Thousands of passengers from Hong Kong to Dublin were stranded as aviation chiefs decided it was too risky to allow planes to fly through the cloud of ash, which is upwards of 6km above the earth's surface.
The ash from the volcano under Iceland's Eyjafjallajokull glacier blew southeast after Wednesday's eruption towards Scotland and Norway, before covering Britain and Scandinavia, according to the London-based Volcanic Ash Advisory Centre.
Although not visible from the ground, volcanic ash can be highly dangerous for aircraft, clogging up the engines and reducing visibility, experts warn.
Norway was the first to ground its flights on Wednesday evening, followed by Scotland overnight and then London, before air traffic controllers announced no flights could go through British and Irish airspace after 1100 GMT (2100 AEST).
Finland closed its northern airspace an hour later, although Helsinki-Vantaa airport remained open, and Denmark and Sweden said they would follow suit.
Belgian air space had been partially closed and would be shut down entirely from 1430 GMT (0030 AEST, Friday) an official said, and Dutch air traffic control said the Netherlands air space was being progressively closed.
Earlier, about 40 to 50 flights were cancelled at Amsterdam's Schiphol airport, all bound for Scandinavia, Britain and parts of Russia, while delays were also reported on US and Canada-bound flights.
Icelandic airports, however, reported no problems.
"The wind is blowing the ash to the east," Hjordis Gudmundsdottir of the Icelandic Airport Authority said, adding: "It's amazing really."
About 300 flights in and out of London's Heathrow and Gatwick airports had already been cancelled before the airspace was closed, leaving many of the 260,000 passengers that typically use the airports each day with nowhere to go.
Flights from all over the world, including Tokyo, Hong Kong, Dubai, Paris and Athens, were affected by the cancellations in northern Europe.
A spokeswoman for Britain's air traffic control service said the airspace closures could also cause European flights to the United States to be re-routed.
"A lot of traffic from Western Europe to America would normally fly through our space," she said.
Some airlines raced to get their flights completed before the cloud hit - Pakistani International Airlines diverted a flight from Lahore to Manchester in northwestern England to London, just before the capital's airports shut.
"It will be difficult to fly to UK and other European countries affected by the ash cloud until it settles completely," said PIA spokesman Sultan Hasan.
British airspace was only supposed to be closed until 1700 GMT (0300 AEST, Friday), although the airline BA said it was grounding all its British flights until Friday morning.
David Rothery, a senior lecturer in earth sciences at Britain's Open University, said flight restrictions were an essential safety precaution.
"This is because if volcanic ash particles are ingested into a jet engine, they accumulate and clog the engines with molten glass," he said.
http://www.iinet.net.au/customers/news/articles/1040016.html
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #49 on Apr 15, 2010, 12:09pm » | |
Iceland Eruption: New Satellite Image of Volcanic Ash Cloud
![[image]](http://img52.imageshack.us/img52/3317/1004151100421241212.jpg "[image]")
This image, acquired on 15 April 2010 by Envisat's Medium Resolution Imaging Spectrometer (MERIS), shows the vast cloud of volcanic ash sweeping across the UK from the eruption in Iceland, more than 1000 km away. The ash, which can be seen as the large grey streak in the image, is drifting from west to east at a height of about 11 km above the surface Earth. (Credit: ESA)
ScienceDaily (Apr. 15, 2010) — This image, acquired today by ESA's Envisat satellite, shows the vast cloud of volcanic ash sweeping across the UK from the eruption in Iceland, more than 1000 km away.
Carried by winds high up in the atmosphere, the cloud of ash from the eruption of the Eyjafjallajoekull glacier in southwest Iceland has led to the closure of airports throughout the UK and Scandinavia, with further disruption in northern Europe expected later. The ash, which can be seen as the large grey streak in the image, is drifting from west to east at a height of about 11 km above the surface Earth. It poses a serious danger to aircraft engines; hence the airspace shut down.
The volcano erupted, for the first time since 1821, on 20 March and started erupting for a second time on Wednesday. The volcano, under the glacier ice, has caused ice melt and subsequent flooding and damage locally.
This image was acquired on 15 April 2010, at 13.25 (CEST) by Envisat's Medium Resolution Imaging Spectrometer (MERIS) while working in Full Resolution Mode to provide a spatial resolution of 300 metres.
http://www.sciencedaily.com/releases/2010/04/100415110042.htm
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #50 on Apr 15, 2010, 12:51pm » | |
The OFFICIAL story:
Recent Earthquake Activity Is Not Unusual, Scientists Say
ScienceDaily (Apr. 15, 2010) — China's tragic magnitude 6.9 earthquake on April 13 and the recent devastating earthquakes in Haiti, Chile, Mexico, and elsewhere have many wondering if this earthquake activity is unusual.
Scientists say 2010 is not showing signs of unusually high earthquake activity. Since 1900, an average of 16 magnitude 7 or greater earthquakes -- the size that seismologists define as major -- have occurred worldwide each year. Some years have had as few as 6, as in 1986 and 1989, while 1943 had 32, with considerable variability from year to year.
With six major earthquakes striking in the first four months of this year, 2010 is well within the normal range. Furthermore, from April 15, 2009, to April 14, 2010, there have been 18 major earthquakes, a number also well within the expected variation.
"While the number of earthquakes is within the normal range, this does not diminish the fact that there has been extreme devastation and loss of life in heavily populated areas," said USGS Associate Coordinator for Earthquake Hazards Dr. Michael Blanpied.
What will happen next? Aftershocks will continue in the regions around each of this year's major earthquakes sites. It is unlikely that any of these aftershocks will be larger than the earthquakes experienced so far, but structures damaged in the previous events could be further damaged and should be treated with caution. Beyond the ongoing aftershock sequences, earthquakes in recent months have not raised the likelihood of future major earthquakes; that likelihood has not decreased, either. Large earthquakes will continue to occur just as they have in the past.
Though the recent earthquakes are not unusual, they are a stark reminder that earthquakes can produce disasters when they strike populated areas -- especially areas where the buildings have not been designed to withstand strong shaking. What can you do to prepare? Scientists cannot predict the timing of specific earthquakes. However, families and communities can improve their safety and reduce their losses by taking actions to make their homes, places of work, schools and businesses as earthquake-safe as possible.
http://www.sciencedaily.com/releases/2010/04/100415114725.htm
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
|
Big Bunny
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| | Re: Earthquakes III
« Reply #51 on Apr 19, 2010, 8:48pm » | |
Seismic activity rises in California
CARA MIA DIMASSA
April 20, 2010
LOS ANGELES: Seismologists are unable to explain a marked recent increase in earthquake activity in Southern California.
There have been 70 quakes greater than magnitude 4.0 in Southern California and Baja California so far this year, the most of any year in the past decade. There were 30 last year and 29 in 2008.
Big earthquakes tend to occur in cycles, and experts have said the region has been in a quiet cycle in recent years.
The string of quakes this year raises the possibility that Southern California might again be entering a more active seismic period. Scientists said the increase did not mean the Big One was imminent, but it could mean more quakes were on the way.
Egill Hauksson, a geophysicist at the California Institute of Technology, said the rate of quakes in the region was ''probably … picking up again'' after a relative lull that lasted more than 10 years.
''What it means is that we are going to have more earthquakes than in the average year. With more earthquakes, we're bound to have more bigger ones. But there are always fewer of those than the smaller ones.''
Scientists, however, have not been able to identify reasons that fully explain the increase.
Many of the earthquakes this year have been aftershocks to a 7.2 temblor that rattled the Mexicali area earlier this month. The border region had experienced smaller quakes before the big one. And there have been more than 1000 aftershocks, including more than a dozen that registered higher than 5.0.
The Mexicali quake was the region's largest since one of 7.3 in the Mojave Desert in 1992. Despite their size, neither quake did catastrophic damage because they occurred in relatively remote areas far from large population centres.
In California, scientists say one of their biggest concerns remains the San Andreas fault, which has produced some of the state's largest earthquakes. Experts have said the San Andreas is overdue for an eruption. State officials have also often noted that only about one in six Californians has earthquake insurance.
http://www.smh.com.au/world/seismic-acti....00419-spbs.html
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
|
Big Bunny
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| | Re: Earthquakes III
« Reply #52 on Apr 19, 2010, 9:05pm » | |
Volcanoes: be afraid, be very afraid - the supervolcano is coming
KATE RAVILIOUS
April 16, 2010
![[image]](http://img696.imageshack.us/img696/867/ash420420x08739580.jpg "[image]")
Smoke and steam hangs over the volcano under the Eyjafjallajokull glacier in Iceland. Photo: AP
Every so often the earth chooses to remind us that we really aren't in control of this planet.
The volcanic eruption in Iceland, which began on Wednesday (?), is just such a reminder.
As ash spews out across northern Europe, grounding all flights across Scandinavia and Britain, we begin to realise how powerless we humans are.
But as volcanic eruptions go, the fireworks on Iceland are small fry.
Scientists rank volcanoes according to how explosive they are, using the volcanic explosivity index (VEI), which goes from zero to eight. The measurement is based on how much material is thrown out of the volcano, how high the eruption goes and how long it lasts.
Like the scale used to measure earthquake size, the VEI is logarithmic - meaning that a volcano with a VEI of five is 10 times more powerful than one with a VEI of four.
As yet, scientists haven't managed to gather enough data to calculate the VEI of Eyjafjoll, but Thorvaldur Thordarson, an expert on Icelandic volcanism at the University of Edinburgh, estimates that this one is probably a two or three - similar to the eruptions seen on Mount Etna on Sicily in 2002 and 2003, and the kind of eruption we expect to see somewhere on earth at least once every year.
By contrast, the eruption of Mount St Helens, in the north-west of the US in May 1980, was a one-in-10-year event, with a VEI of about four.
Meanwhile, Pinatubo's boom in the Philippines in 1991 was a one-in-50- to 100-year spectacle, with a VEI of about five or six.
Bigger still was the eruption of Tambora in 1815, on the island of Sumbawa, Indonesia. Its ash was responsible for some of the spectacular sunsets painted by Turner.
Rated as a seven on the VEI scale (a one-in-1000-year event), it was the most deadly eruption in recorded history, killing more than 70,000 people.
But as the Eyjafjoll event is showing, even baby eruptions can cause quite a nuisance.
The last time Iceland experienced an eruption of this size was in 2004, when the Grimsvotn volcano blew.
"On that occasion the ash cloud went to the north, but this time the jet stream has carried it south-east, towards the UK," Thordarson says.
Having its ash carried into some of Europe's busiest flight paths has made Eyjafjoll big news.
No aircraft can risk flying through the cloud - the chances of choking the engines and stalling the plane are high. And so we have to twiddle our thumbs until Eyjafjoll decides she has let off enough steam.
If Eyjafjoll is anything like Grimsvotn, the eruption will peter out in a day or two, but there is a chance that things could go on for a lot longer.
"We suspect it will end today or tomorrow, but it could last for weeks, months or even years," Thordarson says.
And even if Eyjafjoll goes quiet again soon, that doesn't mean she has finished yet.
"The last time Eyjafjoll erupted [in 1823], it lasted for more than a year, so we could see more of the same disruption over the coming months," says Bill McGuire, director of the Aon Benfield UCL Hazard Research Centre at University College London.
Thordarson agrees, saying that we may well get a number of intermittent explosive events at Eyjafjoll over the next couple of years.
For vulcanologists, this most recent eruption is no surprise.
"There has been lots of unrest under this particular volcano for the past 10 years, which picked up in intensity at the beginning of this year," says Thordarson.
In fact, many vulcanologists are rubbing their hands with glee.
"It is a nice surprise for us, as this one hasn't erupted for a while," says Dougal Jerram, from the University of Durham.
To vulcanologists, Iceland is heaven.
There are 30 active volcanic systems on the island and very frequent firework displays.
Geologists believe the reason for Iceland's explosive nature is that it sits over a "mantle plume" - a rising column of abnormally hot molten rock, originating at the edge of the earth's core.
To make matters even more spectacular, this particular mantle plume has positioned itself under the mid-Atlantic ridge: the crack that runs down the middle of the Atlantic, where the ocean floor divides and continuously spews out fresh lava.
Despite its perfect position, Iceland has failed to live up to its reputation in recent decades.
"The volcanoes have been very quiet over the last half of the 20th century," Thordarson says.
But in the past 10 years, vulcanologists have noticed increased rumblings from below, suggesting that Iceland might be entering a more active phase again and brewing some really big bangs.
If the vulcanologists are right, we could be in for a bumpy ride.
The last time Iceland had a colossal eruption was in 1783. Laki, a fissure close to the Grimsvotn volcano, burst open and threw up fountains of lava and clouds of ash for eight months.
The poisonous sulphur dioxide gas killed over half of Iceland's livestock population and led to a famine that wiped out about a quarter of the country's population.
Meanwhile, as the cloud blew south it wreaked havoc over Europe, too.
"This outpouring of sulphur dioxide during unusual weather conditions caused a thick haze to spread across western Europe, resulting in thousands of deaths throughout 1783 and the winter of 1784," says Jerram.
The fog was so thick that boats across Europe were forced to stay in port.
Further afield, the effects were also severe.
"There is evidence that Laki may have caused the failure of the rice harvest in Japan that year, and weakened the African and Indian monsoon circulation," Thordarson says.
On the explosivity index, Laki is judged to have been a six - the kind of volcano that occurs once every century, on average.
So how would we cope if Iceland produced another Laki tomorrow?
"I think modern society is better equipped to deal with the health and environmental effects, but the economic consequences of halting air traffic for five months or so would be very severe," Thordarson says.
Worse still would be a repeat of an eruption such as that of Oraefajokull, Iceland's largest active volcano, which last erupted in 1362.
"This eruption was two or three orders of magnitude larger than Laki and the largest eruption in Europe in the past 2000 years," says Thordarson.
But when it comes to truly big threats, Iceland's volcanoes are mere distractions. Every 100,000 years or so a catastrophic eruption occurs, known as a "supervolcano".
More than 1000 cubic kilometres of material are blasted into the air and the ash and gas cloud sends earth into a chill for years.
The last time one erupted was 74,000 years ago, when Toba, on the Indonesian island of Sumatra threw out nearly twice the volume of Mount Everest in magma.
Toba was more than 5000 times as explosive as the eruption of Mount St Helens in 1980 and comes in as an eight on the VEI scale.
There is much debate about how devastating Toba was for humans, but without a doubt it will have had a very severe impact.
Some scientists argue that it may even have caused a bottleneck in human evolution.
Previous supervolcanic eruptions have been linked to mass extinction events, such as the Permian extinction 250 million years ago - which wiped out more than 90 per cent of marine species and was associated with an eruption at the Siberian Traps.
And unfortunately, there is no way of avoiding the next super-eruption.
"It is not a question of if, it is a question of when," says McGuire.
Unlike conventional volcanoes, supervolcanoes are not always obvious from the surface, making it difficult for scientists to predict where the next one might be simmering.
Possible contenders for the next eruption include Yellowstone volcano in Wyoming, the Phlegrean fields volcano west of Naples, Italy, and Lake Taupo in New Zealand.
However, there are many other areas where a supervolcano could pop up, including Indonesia, the Philippines, several Central American countries, the Andes, Japan, the Kamchatka peninsula in eastern Russia, and even Europe (the area around Kos and Nisyros in the Aegean Sea might be a supervolcano).
In 2005, a working group (commissioned by the Geological Society of London) investigated the threat of a supervolcano and concluded that "an area the size of North America or Europe could be devastated, and pronounced deterioration of global climate would be expected for a few years following the eruption".
"Such events could result in the ruin of world agriculture, severe disruption of food supplies, and mass starvation. The effects could be sufficiently severe to threaten the fabric of civilisation."
This week's fireworks on Iceland are just sparklers compared to what is to come.
http://www.smh.com.au/world/science/volc....0416-sj01.htm l
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #53 on Apr 19, 2010, 9:10pm » | |
Volcano ash sparks health fears
REYKJAVIK
April 18, 2010
![[image]](http://img101.imageshack.us/img101/1112/iceland200x09219751.jpg "[image]")
No sign of abating … the volcano in Iceland is spewing ash over Europe. Photo: AP
HEALTH authorities have warned that the fallout of volcanic ash over parts of Iceland could jeopardise the safety of its drinking water.
And a geophysicist said the eruption showed no signs of abating.
Halldor Runolfsson from the Icelandic Food and Veterinary Authority said there were concerns for human health but the greatest risk was to livestock.
''It is important to prevent the ash from reaching water supplies, both for public and animal health reasons and for safe milk production.''
His colleague Guthjon Gunnarsson said the agency was evaluating the quality of drinking water, which was mostly protected because it was sourced from under the ground.
Dr Runolfsson said the ash posed the greatest risk to livestock because it contained high levels of fluoride, which can cause problems in bones and teeth.
Since the eruption began on Wednesday, it has been spewing a six-kilometre plume of ash into the sky, sending a giant cloud of it towards Europe and prompting the continent's biggest air travel shutdown since World War II.
The question for scientists is how long the eruption might continue, particularly at its current strength. Geophysicist Pall Einarsson, from the Institute of Earth Sciences at the University of Iceland, said that question could not yet be answered.
Iceland had many volcanoes, and their eruptions often followed a pattern, Professor Einarsson said. ''Usually they are most vigorous in the beginning. But this volcano is very different from that.''
Researchers were monitoring the volcano for indications that the eruption was tapering off.
![[image]](http://img62.imageshack.us/img62/8792/volcano420x09164368.jpg "[image]") ![[image]](http://img406.imageshack.us/img406/7387/839412icelandvolcano336.jpg "[image]")
Fireworks display... lightning streaks across the sky as lava flows from Eyjafjallajokul. Low-energy lightning around Eyjafjallajokull volcano. Lightning is often active during eruptions, arcing between particles as they exit the volcanic vent at around 100 metres per second. The dramatic volcanic eruption has entered a new phase - producing less smoke but bubbling with lava and throwing up chunks of molten rock. Picture: AP / Jon Pall Vilhelmsson
One complication was the eruption's location, under the Eyjafjallajokull glacier. The underside of the ice has melted, causing flooding, forcing evacuations and destroying bridges and roads. The rest of Europe is concerned about how the meltwater might affect the volcano and the ash it generates.
Jennie Gilbert, from the University of Lancaster in Britain, said the presence of water could affect the characteristics of the sandlike ash produced by the volcano. As the molten rock hits the cold water, it is fused into a glassy material. When the pressure builds up and the volcano explodes, this material breaks up into fine particles. In Britain, the Health Protection Agency said some particles might settle to the ground but may not be visible.
It advised people - particularly those with respiratory problems - to have medicines on hand and to limit outdoor activities.
http://www.smh.com.au/world/volcano-ash-sparks-health-fears-20100417-slgb.html
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
|
Big Bunny
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| | Re: Earthquakes III
« Reply #54 on Apr 19, 2010, 9:20pm » | |
Getting a bird's eye view of Eyjafjallajokull's power and wrath
PHILIP SHERWELL AT THE VOLCANO
April 19, 2010
![[image]](http://img192.imageshack.us/img192/8489/volcano2420x09772058.jpg "[image]")
Wreaking havoc... the Icelandic volcano.
THE power and wrath of Eyjafjallajokull has come into dramatic clarity in the past few days as the clouds parted for the first time since the glacier-topped volcano threw world air travel into turmoil.
Fresh eruptions thrust torrents of molten rock through the shattered ice sheets in the mountain crater, spewing a towering wall of ash, dust and steam high into the air.
I was aboard a small six-seater helicopter carrying the first civilian passengers to approach the scene on Friday night when coastguard observers in an aircraft high above warned the pilot to be wary of the latest barrage of explosions.
The plumes dwarfed the helicopter as we flew above a riverbed dotted with thousands of cannon balled-sized lumps of ice left behind when an earlier eruption set off a glacial flood.
Strong winds whipped the shroud of black, grey and white hues as it soared to more than 6000 metres above the ring of cloud that clung to the ice-clad mountain top. The power of the blasts has carried the ash - a potent threat to aircraft engines - even further up into the North Atlantic jet stream that passes over the island near one of the world's busiest flight paths.
It is a rare combination and it was clear that, for now at least, Eyjafjallajokull was not easing up. Vulcanologists said it was impossible to predict how long the eruptions would continue or whether an even more violent neighbouring volcano might follow suit.
Eyjafjallajokull is not one of the biggest or most volatile of Iceland's 22 active volcanoes. Hidden from our view by the volcanic debris lies an even greater threat, the larger crater of nearby Katla.
Eyjafjallajokull has erupted only three times since the Vikings settled the island in the ninth century, most recently when it blew intermittently for 14 months in the early 1820s.
Each time it has been followed within months or a year by a big eruption at Katla. That volcano has also blown another 20 or so times in its own right, on average once every 60 to 80 years. Another is long overdue.
Matthew Jones, a British glacier expert, said there was no evidence of ground rumblings beneath Katla. ''But we do know from past ash layers embedded together that the two volcanoes seem to be interconnected in the timings of previous explosions.''
http://www.smh.com.au/travel/travel-news....0418-smnu .html
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #55 on Apr 19, 2010, 10:03pm » | |
Eruption surge sends new ash cloud towards Britain
April 20, 2010 - 11:56AM
The eruption of a volcano in Iceland strengthened yesterday, sending a new ash cloud towards Britain, the country’s air authorities said.
"The volcano eruption in Iceland has strengthened and a new ash cloud is spreading south and east towards the UK," said the National Air Traffic Services (NATS), which manages British airspace.
"Latest information from the Met Office [weather forecasting service] shows that the situation is worsening in some areas," NATS said in a statement.
![[image]](http://img402.imageshack.us/img402/7290/gallvolcanicashcloud600.jpg "[image]")
A cloud of volcanic ash is seen spreading from the southern side of Iceland in this satellite photograph.
It added that Scottish airports should still be open from 7am on Tuesday (4pm AEST), as had been announced earlier in the day, but the situation for Northern Irish airports was uncertain.
More airspace over England may become available from 1pm on Tuesday (10pm AEST) although not as far south as the main London airports, NATS said.
But it added that "the situation is likely to change overnight".
News of the latest cloud comes as European governments started opening the continent’s airspace to new flights, giving hope to hundreds of thousands of passengers around the world trapped as volcanic ash in the atmosphere grounded airlines.
The huge cloud of ash that has blanketed Europe forced the cancellation of another 20,000 flights on Monday and Britain and other governments sent navy ships and deployed other measures to rescue stranded passengers.
But under relentless pressure from airlines facing a new billion dollar-plus bill, EU transport ministers agreed to ease restrictions from Tuesday.
European air traffic control group, Eurocontrol, predicted after the announcement on easing curbs that flights over the continent could be running normally again by Thursday.
British Airways said it hoped to resume flights into and out of London from Tuesday evening.
France said it would begin to reopen airports progressively from Monday with restricted flights from Paris to start from early on Tuesday.
Flights over Germany remained banned until the early hours of Tuesday, but some operated with special permission.
A spokeswoman for German carrier Lufthansa said it had permission to land 50 flights from Asia, Africa and North and South America, carrying 15,000 passengers in total.
Three KLM flights carrying passengers left Amsterdam-Schiphol airport on Monday for Shanghai, Dubai and New York, the Dutch Transport Minister announced.
EU Transport Commissioner Siim Kallas said: "From tomorrow morning on, we should progressively see more planes start to fly."
But he insisted: "There cannot be any compromise on safety. All the decisions must be based on scientific evidence and expert analysis."
Nearly 7 million passengers have been affected by blanket shutdowns, which governments said were essential but which airlines blame for unnecessary chaos and massive financial losses.
In Europe marooned passengers juggled hellish combinations of rail, boat and road links, zig-zagging across borders in desperate attempts to make it home - whether to the other end of Europe or to the United States.
Britain ordered its flagship aircraft carrier HMS Ark Royal and HMS Ocean and HMS Albion to pick up thousands of Britons from France - where they have come from all over Europe - and Spain.
"This is the biggest challenge to our aviation transport network for many years," Prime Minister Gordon Brown said.
Spain, one of the few countries operating normally, struck an agreement with Britain, France and Germany to fly hundreds of thousands of their nationals back to Europe via Spanish airports.
EU leaders have come under fire for their dealing with the chaos sparked by Iceland’s Eyjafjoell volcano, as forecasters predicted the ash cloud could soon reach Canada.
"This is a European embarrassment and it’s a European mess," said Giovanni Bisignani, director general of the International Air Transport Association.
Air France, British Airways, KLM and Lufthansa reported no problems after flights to test fears the ash cloud would destroy jet engines.
Authorities in Sweden, Croatia, Hungary and the Czech Republic announced the resumption of flights.
Romania and Bulgaria announced their airspace had been reopened.
But as airlines argued their case, a senior US military official said the ash had affected one of NATO’s F-16 fighter planes, which detected a glass build-up inside its engine.
Ash from volcanoes can be turned into a glass form at high temperatures when it passes through a jet engine.
Companies are losing €200 million [$292.6 million] a day, IATA said.
http://www.smh.com.au/travel/travel-news....00420-spps.html
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #56 on Apr 21, 2010, 7:36pm » | |
Iceland volcano: why we were lucky we weren't wiped out
The volcanic ash cloud from Eyjafjallajokull has caused travel chaos and misery. But we were lucky. An eruption in the future could wipe out the human race
* Simon Winchester
* guardian.co.uk, Wednesday 21 April 2010 21.00 BST
![[image]](http://img202.imageshack.us/img202/3500/aphoneboothlieshalfb001.jpg "[image]")
A phone booth lies half-buried in volanic ash after the eruption on Montserrat, 1998. Photograph: AP/Gregory Bull
The map is almost uncannily similar to today's: a spray of black dots showing the recorded sightings of a foul grey haze spreading across Europe, from Helsinki to Naples, from Heligoland to Mallorca, and reaching eventually to Aleppo and Damascus – and all of it caused by clouds of ash from an immense volcano erupting far across the sea in Iceland.
But this was a map made from data collected in 1783. The volcano was called Laki, it erupted for eight dismal months without cease, ruined crops, lowered temperatures and drastically altered the weather. It killed 9,000 people, drenched the European forests in acid rain, caused skin lesions in children and the deaths of millions of cattle. And, by one account, it was a contributing factor (because of the hunger-inducing famines) to the outbreak six years later of the French revolution.
Great volcanoes have a habit of prompting profound changes to the world – very much greater in extent than the most savage of earthquakes and tsunamis, even though the immediate lethality of the latter is invariably much more cruel. Though ground-shaking events are generally fairly local in extent, their potential for killing can be terrific: 250,000 died after the Tangshan earthquake in China in 1975; and a similar number died in the Indian ocean tsunami of 2004. Volcanoes seem by contrast relatively benign: the accumulated total number of deaths in all of the great volcanoes of the last 300 years has probably not exceeded a quarter of a million: the total number of casualties from a hundred of the biggest recent eruptions has been no more than those from a single giant earthquake.
But there is a signal difference. Earthquakes and their aftershocks, once done, are done. Volcanoes, however, often trigger long-term and long-distance ill-effects, which history indicates generally far outweigh their immediate rain of death and destruction. Emanations of particles from the tiniest pinprick in the earth's crust, once lifted high into the skies by an explosive eruption, can wind themselves sinuously and menacingly around the entire planet, and leave all kinds of devastation in their train. They can disrupt and pollute and poison; they can darken skies and cause devastating changes in the weather; they can and do bring about the abrupt end to the existence of entire populations of animals and people.
Earthquakes and tsunamis have never been known to cause extinctions; but volcanoes and asteroid collisions have done so repeatedly – and since the earth is today still peppered with scores of thousands of volcanoes ever yearning to erupt, they and the dramatic long-term effects of their eruptions are in fact far more frequent, far more decisive, and far greater than those that are triggered by any other natural phenomenon on the planet.
It is worth remembering that ours is a world essentially made from and by volcanoes. They are creatures that will continue to do their business over the aeons, quite careless of the fate of the myriad varieties of life that teems beneath them and on their flanks. Including, of course, ours.
There is perhaps no better recent example of the havoc that a big eruption can cause than that which followed the explosive destruction of Mt Toba, in northern Sumatra, some 72,000 years ago (which, in geological time, is very recent indeed). The relics of this mountain today are no more than a very large and beautiful lake, 60 miles long and half a mile deep – the caldera that was left behind by what is by most reckonings the largest volcanic explosion known to have occurred on the planet in the last 25 million years.
On the widely used volcanic explosivity index (VEI), Toba is thought to have been an eight – meaning that in the unusually flamboyant official language of vulcanology it was a super-plinian type eruption with mega-colossal characteristics (Eyjafjallajökull is by contrast listed as a strombolian type, with its characteristic regarded as merely gentle, and having a probable VEI rating of just two).
About 680 cubic miles of rock were instantly vaporised by the super-eruptive blast of Toba, all of which was hurled scores of thousands of feet into the air. This this is what did the lasting damage, just as Iceland's high-altitude rock-dust is doing today. But while we today are merely suffering a large number of inconvenienced people and a weakening of the balance sheets of some airlines, the effect on the post-Toban world was catastrophic: as a result of the thick ash clouds the world's ambient temperature plummeted, perhaps by as much as 5C – and the cooling and the howling wave of deforestation and deaths of billions of animals and plants caused a sudden culling of the human population of the time, reducing it to maybe as few as 5,000 people, perhaps 1,000 breeding pairs. Many anthropologists believe that the event caused a sudden evolutionary bottleneck, with genetic implications that linger to this day. Put more crudely, humanity was nearly wiped out by Toba, and only by the merest hair's-breadth did our ancestors of 72,000 years ago manage to cling on and bequeath to us our current existence.
Mercifully, from humanity's point of view, there have been very few Tobas known in planetary history. They are probably so large that they reach the upper limit of the kind of eruptions that can physically occur on earth – one VEI-8 event occurs only every 100,000 years or so. Yet of those known to have occurred, two have taken place in Britain (mainly because Britain has such a vast variety of geology, with almost every age of rock known in the world found somewhere between Cape Wrath and the Port of Dover). They are comfortingly ancient: both – the volcano that created Scafell in the Lake District, and the other that gave us Glen Coe in the Western Highlands – took place more than 400 million years ago.
But others of the 47 known VEI-8 volcanoes are more alarmingly recent. Taupo in New Zealand erupted with mega-colossal force some 22,500 years ago. The newer of the great eruptions that helped form the mountains of today's Yellowstone national park in Wyoming took place just 640,000 years ago, and all the current signs – from such phenomena as the rhythmic slow rising and falling of the bed of the Yellowstone river, as if some giant creature is breathing far below – suggest another eruption is coming soon. When it does, it will be an American Armageddon: all of the north and west of the continent, from Vancouver to Oklahoma City, will be rendered uninhabitable, buried under scores of feet of ash. (I mentioned this once in a talk to a group of lunching ladies in Kansas City, soothing their apparent disquiet by adding that by "soon" I was speaking in geologic time, and that meant about 250,000 years, by which time all humankind would be extinct. A woman in the front row exploded with a choleric and incredulous rage: "What?" she said. "Even Americans will be extinct?")
Ratcheting down the scale a couple of notches, to the only slightly less gigantic eruptions that are classified as VEI-7 and VEI-6, and a host of more familiar eruptions come into view. These include Santorini, the Aegean volcano whose destruction around 4,000 years ago may have triggered the collapse of the Minoan civilisation; Laki, the 1783 Icelandic volcano mentioned above, and which most obviously parallels today's events at Eyjafjallajökull; the Javan volcano of Krakatoa, which erupted so infamously in August 1883; and the rather more profoundly world-affecting eruption of 1815, also in the Dutch East Indies, of the huge stratovolcano on Sumbawa Island, known as Tambora. Each of these had massive after-effects, and all of the effects were global in their extent.
Tambora is the most notorious, not least because it was so immense: almost 40 cubic miles of pulverised Sumbawan rock were hurled into the sky, which darkened, cooled and polluted a world that, unlike in Toba's day, was already well populated and widely civilised. The consequences ranged from the dire – a lowering of temperature that caused frosts in Italy in June and snows in Virginia in July, and the failure of crops in immense swathes across Europe and the Americas – to the frankly ludicrous – Irish migrants, promised better weather in New England, found it on landing to be every bit as grim as the Connemara and Cork they had left, and so either went home, or pressed on in hope to California.
And Tambora's eruption had its effects on art also: a gloomy Byron wrote the gloomiest of poems, Darkness ("Morn came and went, and came, and brought no day/ And men forgot their passions in the dread/ Of this their desolation . . ."); Mary Shelley, it is said, became so fed up with the rain while visiting Byron in Geneva that she followed suit and wrote her exceptionally gloomy novel Frankenstein. Only JMW Turner rose more cheerfully to the occasion: the lurid colours of many of his paintings, it is said, owe much to the flaming Tambora sunsets that had half the world astonished, and Turner evidently inspired.
Krakatoa's immediate aftermath was dominated initially by dramatic physical effects – a series of tsunamis that were measured as far away as Portland Bill and Biarritz, a bang of detonation that was clearly heard (like naval gunfire, said the local police officer) 3,000 miles away on Rodriguez Island, and a year's worth of awe-inspiring evening beauty – astonishing sunsets of purple and passionfruit and salmon that had artists all around the world trying desperately to capture what they managed to see in the fleeting moments before dark. A Londoner named William Ascroft left behind almost 500 watercolours that he painted, one every 10 minutes like a human film camera, from his Thames-side flat in Chelsea; Frederic Church, of America's so-called Hudson River School, captured the crepuscular skies over Lake Ontario in their full post-Krakatoan glory; and many now agree that Edvard Munch had the purple and orange skies over Oslo in mind when 10 years afterwards he painted, most hauntingly, The Scream.
Yet there was an important legacy to Krakatoa's eruption that was not shared by the other giant volcanoes of the time. Close mapping of the spread of the 1883 sunsets showed them girdling the earth in a curious set of spirals, the stratospheric aerosols evidently being borne around the world on high-altitude winds that no one at the time knew even existed. An atmospheric scientist in Hawaii mapped them and decided to call the air current the equatorial smoke stream; it later became, more elegantly and economically, the jet stream. There has to be some irony that the jet stream that drives today's Icelandic dust so dangerously over Britain and mainland Europe is a phenomenon that was first discovered as a direct consequence of the study of Krakatoa.
And yet, of all the consequences of the truly great volcanoes of the past, the phenomenon of mass extinctions of life must surely be the most profound and world-changing of all. Between two and five major extinction events occur in the world every million years or so. We humans have not thus far been privileged to observe one of them – hardly surprisingly, since they would probably occur so slowly as to be barely noticeable. However, with painstaking care, palaeontological evidence is currently being amassed to link sudden and catastrophic changes in world climate, changes that promote such extinction crises, with the known major eruptions of the past, and with what are known as flood basalt events (such as those that have been triggered specifically in the past by eruptions of Eyjafjallajökull and her neighbouring volcano in Iceland, Katla, which is herself currently well overdue for an eruption). It is a study that opens up a fascinating speculative possibility.
For what if the kind of event that we have seen this month, and which caused us all in Europe such commercial inconvenience, is in fact not just a minor volcanic hiccup, but the beginning of an event that causes in time a mass extinction of some form of earthbound life? And further, since we know from the history books that the massive eruption of Santorini once had the power to destroy one proud part of human society, what if the extinction we might be beginning to see turns out to be what will one day surely occur, and that is the extinction of us?
Simon Winchester is a journalist and author; one of his books is Krakatoa: The Day The World Exploded.
http://www.guardian.co.uk/world/2010/apr....tion-human-race
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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Big Bunny
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| | Re: Earthquakes III
« Reply #57 on Apr 23, 2010, 4:13pm » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
23-APR-2010 10:03:07 -37.42 -72.94 6.1 35.0 CENTRAL CHILE
http://www.iris.edu/seismon/
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
|
Big Bunny
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| | Re: Earthquakes III
« Reply #58 on Apr 24, 2010, 8:35pm » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
24-APR-2010 12:11:55 -6.32 131.05 4.5 35.0 TANIMBAR ISLANDS REG., INDONESIA
24-APR-2010 11:28:38 0.92 120.55 4.5 10.0 MINAHASSA PENINSULA, SULAWESI
24-APR-2010 07:41:03 -1.86 128.16 6.0 53.4 HALMAHERA, INDONESIA
http://www.iris.edu/seismon/
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
|
Big Bunny
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| | Re: Earthquakes III
« Reply #59 on Apr 26, 2010, 2:17am » | |
Latest significant seismic activity:
DATE LAT LON MAG DEPTH REGION
26-APR-2010 04:09:47 22.20 123.64 4.6 10.0 SOUTHEAST OF TAIWAN
26-APR-2010 02:59:50 22.25 123.73 6.5 10.0 SOUTHEAST OF TAIWAN
http://www.iris.edu/seismon/
|
"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."
Arthur Schopenhauer, Philosopher, 1788-1860
"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."
John F. Kennedy |
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