Posts Tagged ‘volcanos’

Supervolcanos can erupt sponataneously without an external trigger

January 7, 2014

New research suggests that supervolcanos do not need an external trigger to erupt. Bouyancy effects and the magma volume could be sufficient for spontaneous eruption.

Wim J. Malfait, Rita Seifert, Sylvain Petitgirard, Jean-Philippe Perrillat, Mohamed Mezouar, Tsutomu Ota, Eizo Nakamura, Philippe Lerch, Carmen Sanchez-Valle. Supervolcano eruptions driven by melt buoyancy in large silicic magma chambersNature Geoscience, 2014; DOI:10.1038/ngeo2042

From the Press Release:

Scientists have reproduced the conditions inside the magma chamber of a supervolcano to understand what it takes to trigger its explosion. These rare events represent the biggest natural catastrophes on Earth except for the impact of giant meteorites. Using synchrotron X-rays, the scientists established that supervolcano eruptions may occur spontaneously, driven only by magma pressure without the need for an external trigger. The results are published in Nature Geosciences.

A well-known supervolcano eruption occurred 600,000 years ago in Wyoming in the United States, creating a huge crater called a caldera, in the centre of what today is Yellowstone National Park. When the volcano exploded, it ejected more than 1000 km3 of ash and lava into the atmosphere, 100 times more than Mt Pinatubo in the Philippines did in 1992. Big volcanic eruptions have a major impact on the global climate. The Mt Pinatubo eruption decreased the global temperature by 0.4 degrees C for a few months. The predictions for a super volcano are a fall in temperatures by 10 degrees C for 10 years.

Abstract: Super-eruptions that dwarf all historical volcanic episodes in erupted volume and environmental impact are abundant in the geological record. Such eruptions of silica-rich magmas form large calderas. The mechanisms that trigger these super-eruptions are elusive because the processes occurring in conventional volcanic systems cannot simply be scaled up to the much larger magma chambers beneath supervolcanoes. Over-pressurization of the magma reservoir, caused by magma recharge, is a common trigger for smaller eruptions, but is insufficient to generate eruptions from large supervolcano magma chambers. Magma buoyancy can potentially create sufficient overpressure, but the efficiency of this trigger mechanism has not been tested. Here we use synchrotron measurements of X-ray absorption to determine the density of silica-rich magmas at pressures and temperatures of up to 3.6 GPa and 1,950 K, respectively. We combine our results with existing measurements of silica-rich magma density at ambient pressures to show that magma buoyancy can generate an overpressure on the roof of a large supervolcano magma chamber that exceeds the critical overpressure of 10–40 MPa required to induce dyke propagation, even when the magma is undersaturated in volatiles. We conclude that magma buoyancy alone is a viable mechanism to trigger a super-eruption, although magma recharge and mush rejuvenation, volatile saturation or tectonic stress may have been important during specific eruptions.

Supervolcanos do not occur all that often – perhaps one every 50,000 to 100,000 years. When they do occur they devastate a large geographical area and affect the climate for a decade or so. How much destruction of organic life occurs depends on the geographical area affected and the life that is extant there.

New Zealand’s Taupo Volcano was the most recent and erupted about 26,500 years ago. With a VEI of 8, just over 1,000 kmof ash were ejected. Though modern man had reached Australia by then, the effects of this eruption do not seem to have significantly delayed the march of humans. The Toba eruption 74,000 years ago occurred when the total population of all human species (Modern Humans, Neanderthals, Denisovans …..) was between 1 and 10 million. This eruption is also classified as a VEI of 8 and 2,800 km³ of material was ejected. Life was virtually extinguished from India to South East Asia. The effects were devastating not only in the fall out-zone but also – it seems – in hampering the expansion of modern humans out of AfricarabiaThis eruption may thus have caused one of the critical bottlenecks which has determined the subsequent evolution and expansion of humans. 

Image

Toba Fallout (Smithsonian Institute)

While a supervolcano could erupt at any time, it is much more probable to occur than a major asteroid collision with the earth (one in 100,000 years as opposed to once in tens of millions of years). But the volume of magma involved suggests that some early detection (perhaps 5 -10 years) may be possible. For the pressure to build up sufficiently in such a volume a significant bulging of the earth’s crust is likely and should be detectable. But while science fiction can imagine a battery of nuclear warheads to divert an oncoming asteroid in its trajectory, it is difficult to conceive of any way to prevent a supervolcano from erupting. Geo-engineering on a  scale massive enough to relieve some of the pressure in the magma is just conceivable at the edge of fantasy but even that could not prevent the eruption.

Advertisements

Undersea volcanic activity creating new island chain at Norway’s Loki’s Castle

August 3, 2013

South of Svalbard between Norway and Greenland there is vigorous and active field of hydrothermal vents on the sea floor along the Mid-Atlantic Ridge. The field lies in Norwegian waters and is located at  73°33′N 8°09′Ø, about 300 km west of Bear Island and about 600km east of Jan Mayen Island and at a depth of about 2,350m. It was discovered in 2008 by researchers from the University of Bergen and has been called Loki’s Castle (Lokes slott in Norwegian).

Loki's Castle on the Mid-Atlantic Ridge

Loki’s Castle on the Mid-Atlantic Ridge

In 2008, University of Bergen researchers found metal deposits and unique wildlife in the environment created by the hydrothermal vents.

University of Bergen News

This summer a team led by the director of UiB’s Centre for Geobiology, Professor Rolf Birger Pedersen, discovered five new hydrothermal vents in Loki’s Castle. The vents were discovered at depths ranging from 100 to 2,500 metres. In this area, which is the most geological active part of Norway, a new volcanic seabed is formed at a rate of two centimetres a year.

… Norway is a volcanic country on par with Iceland. The difference being that whereas Iceland’s volcanoes are onshore, Norway’s volcano landscape is in the deep sea. Norway’s volcanoes are lined up underwater in large active earthquake zones, and there are hydrothermal vents churning out hot water – at 320 degrees Celsius – which gives rise to unique ecosystems and metal deposits on the seabed. ….

…. For the past ten years, researchers and students from the centre have explored this volcanic underwater world. Through their summer expeditions to the area, they have discovered new Norwegian nature every year. In this period they have surveyed hundreds of undersea volcanoes and a number of hydrothermal vents. Loki’s Castle (Lokeslottet), Soria Moria and Trollveggen are the names given to the hydrothermal vents discovered by the UiB researchers in 2005 and 2008. ..

 They have found significant metal deposits that are formed around the hydrothermal vents in Loki’s Castle. The material value of these deposits remains unknown, but the mining industry is already showing a growing interest in exploiting these resources on the seabed. Deep-ocean mining could become a reality in the not too distant future. The distinctive wildlife in the deep seas, with the hydrothermal vents as oases of a unique genetic life, means that any industrial activity must be weighed against environmental concerns.

Based on their knowledge, the UiB researchers are thus proposing that deep-marine nature parks should be established as soon as possible. This is of particular importance for Norway, with vast deep-sea areas to manage. This management must be based on scientific knowledge.

Video of the undersea volcanoes.

The Local

“We have discovered five new vent fields in Norwegian national waters between Jan Mayen island and Loki’s Castle,” Rolf Pedersen, the professor leading the research, told The Local.  “The vent fields were discovered during a cruise with RV GO Sars in July this summer. ……. 

Pedersen made his name in 2008 when he discovered the underwater volcanic range Loki’s Castle. The new discovery comprises hundreds more volcanos, some just 20m below the surface. 
 
“We have found volcanoes at such a shallow level and they could break the surface at any time and form a new island group,” Pedersen told VG newspaper.  “We have long known that Iceland has both volcanic activity and hot springs, but we thought that we did not have anything like that in Norway. But we do, it was only under water.” 
 
The scientists have already discovered some 50 new species on the site, which Olsen said could lead to new drugs being developed. 
 
“There are biological species which haven’t been discovered before that live in extremely harsh environments. This brings the potential to discover new molecules that we haven’t been aware of which could be used in the development of drugs.” 
=================

In Norse mythology Loki was one of the jǫtnar, a mythological race, and a god.

Loki is the son of Fárbauti and Laufey, and the brother of Helblindi and Býleistr. By the jötunn Angrboða, Loki is the father of Hel, the wolf Fenrir, and the world serpent Jörmungandr. By his wife Sigyn, Loki is the father of Narfi and/or Nari. And by the stallion Svaðilfari, Loki is the mother—giving birth in the form of amare—to the eight-legged horse Sleipnir. In addition, Loki is referred to as the father of Váli in the Prose Edda.

Loki’s relation with the gods varies by source. Loki sometimes assists the gods and sometimes causes problems for them. Loki is a shape shifter and in separate incidents he appears in the form of a salmon, mare, seal, a fly, and possibly an elderly woman. Loki’s positive relations with the gods end with his role in engineering the death of the god Baldr. Loki is eventually bound by the gods with the entrails of one of his sons.

Could solar flare last week be linked to two major earthquakes yesterday?

April 17, 2013

Like primitive man I am overwhelmed by the power of the Sun and a firm believer that even minute solar effects can have a major effect on the Earth and its systems. (I also note that my deification of the Sun must be similar to that by our ancient ancestors and is probably not unconnected to my moving to Scandinavia). In any case I am convinced that for climate

“Solar effects are much more profound than many so-called climate scientists like to admit”,

but I am not sure how strong the link to earthquakes is.

The link between solar effects (radio flux, sunspots, magnetic reversals, proton events….) and volcano activity and earthquakes has been postulated and studied many times but if any such link does exist it is not something obvious and it is by unknown mechanisms. For some this search for such a link is not “science” and there is no link. For others it can be a lifetime’s quest. But “intuition” and “gut-feeling” keeps me believing that there must be a connection. It could well be that the build-up of stresses upto some “breaking point” within the earths crust are a result of ongoing geologic processes and do not need any external trigger like solar activity or the position of the planets to be unleashed. But even continental drift and the build-up of seismic or volcanic stresses are all – ultimately – driven by energy fluxes. And all energy fluxes on Earth can eventually be traced to the Sun (except perhaps if the energy is from any ongoing nuclear reactions in the Earth’s core).

There were two major earthquakes yesterday – USGS

  1. 6.6, 23km ESE of Aitape, Papua New Guinea, 2013-04-16 22:55:27 UTC, 13.0 km deep
  2. 7.8, 83km E of Khash, Iran, 2013-04-16 10:44:20 UTC, 82.0 km deep

And – I note in passing – on April 11th – 5 days ago there was a solar flare and a Coronal Mass Ejection (CME) event. Could be just a coincidence of course – but perhaps not …

Discovery News: APR 11, 2013 03:00 PM ET

The sun has unleashed the biggest solar flare of the year, quickly followed by an Earth-directed coronal mass ejection (CME). Both phenomena have the potential to impact communications and electronics on Earth and in orbit.

Although the sun is currently experiencing “solar maximum” — the culmination of its approximate 11-year cycle — scientists have noted that this particular maximum is a lot quieter than predicted. At this time, the sun should be bubbling with violent active regions, exhibiting sunspots, popping off flares and ejecting CMEs. But so far, the sun seems to be taking it relatively easy.

This morning (at 0716 UT), active region (AR) 1719 erupted with an M-class flare. With a rating of M6.5, this event is the most energetic flare of 2013 (although it’s a lot less impressive than 2012′s X-class fireworks). What’s more, the site of the explosion unleashed a CME in our direction.

A CME is a magnetic ‘bubble’ containing high-energy solar particles. When the CME hits Earth’s global magnetic field, it may align just right to generate a geomagnetic storm. Should this happen, we’ll be able to measure the extreme magnetic distortion of the magnetosphere and bright aurorae at high latitudes may result. Aurorae are caused when solar particles are injected into the polar regions via the Earth’s magnetic field — the particles then collide with atmospheric gases, generating a beautiful light display.

This morning’s CME was clocked traveling at a breakneck speed of 600 miles per second — at that rate it should hit Earth in the early hours of Saturday morning (April 13).

Shortly after the M-class flare erupted, a weak solar energetic particle (SEP) event was detected. This “radiation storm” was the result of relativistic particles slamming into the Earth’s upper atmosphere originating from the flare site.

Image: NASA’s Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 EDT on April 11, 2013. This image shows a combination of light in wavelengths of 131 and 171 Angstroms. Credit: NASA/SDO

El Hierro Volcano Update – Red Alert continues and La Restinga evacuated

October 11, 2011

Update 11/10 – 17:17 UTC People in La Restinga have been evacuated to Valverde with buses and private vehicles. They are asked to stay with family if possible or can spend the night in a student home or in tents in Valverde. La Restinga people who were not at home when the Red Alert was called were denied to enter their homes. This happened also to people living in the higher parts of La Restinga! Police threatened people protesting against the fact they could not get belongings from their houses with high fines.  Only the press is admitted to La Restinga!

Earthquakes upto September 30th - El Hierro: image http://earthquake-report.com

Red alert issued for undersea volcanic eruption of the El Hierro island coast (Canary Islands)

October 11, 2011

From iweather:

El Hierro. Google Maps

El Hierro: Google maps via iweather

Spain’s Instituto Geográfico Nacional (IGN) confirmed on Tuesday that an underwater eruption has occurred five kilometres off the southern coastline of El Hierro, the smallest of the Canary Island. The eruption is Spain’s first since the eruption in 1971 of the Teneguía volcano on the island of La Palma (Canary Islands).

The IGN says all three of its seismic stations on El Hierro in the Canary Islands have registered a volcanic tremor of low frequency in the south of the island at La Restinga, the southern-most village in the Canaries.  The estimated 537 residents of the town were summonsed to a local football field on Tuesday afternoon to be briefed on evacuation procedures.

A Red Alert has since been issued by local authorities for the town. A notice posted on the Emergencia El Hierro website on Tuesday evening stated: “Phase pre-eruptive. It involves the initiation of a preventive evacuation. Make yourself available to the authorities.”

Scientists from IGN and CSIC (Consejo Superior de Investigaciones Científicas), meanwhile, have conducted a reconnaissance flight over the sea to the area south of the island, where they have located dead fish floating on the surface five kilometres from the coast. The dead fish were identified in an area where lower seismic magnitude occurred on October 9, at a depth of approximately 2 km.

The present volcanic activity is understood to be occurring at a depth of 600 metres (just under one kilometre) below sea level, in the Las Calmas sea. …..  English language newspaper  islandconnections.eu reported: “The martime chief for the province of Santa Cruz de Tenerife Antonio Padrón has issued a recomendation that boats should not sail closer than four miles off El Hierro. Divers have also been told to suspend all activities.” ….

The eruption takes place amidst an unprecedented earthquake swarm in El Hierro. The number of earthquakes recorded since July 17, 2011 on El Hierro has now exceeded 10,000. ……

El Hierro pictured from space by the MODIS satellite on Tuesday afternoon, 11 October

El Hierro pictured from space by the MODIS satellite on Tuesday afternoon, 11 October: image via iweather

More details at http://www.irishweatheronline.com/news/earth-science/geology/volcanic-red-alert-issued-as-residents-are-evacuated-from-el-hierro-town/41346.html

 

 

Merapi eruptions slowing down but still deadly

November 13, 2010

Mount Merapi volcano continued spewing hot gas ash but not as violently as before. But the death toll continues to climb as people succumb to their injuries.

Mount Merapi spews volcanic material as seen from Argomulyo, Indonesia, Friday, Nov. 12, 2010.(AP Photo/Achmad Ibrahim)

The Jakarta Globe now puts the toll at 240 lives:

Indonesia’s Mount Merapi volcano has killed 240 people since it began erupting late last month, with more than 390,000 people in makeshift camps, an official said. That figure continues to rise as people with severe burns die from their wounds and officials count those who have died from respiratory problems, heart attacks and other illnesses related to the blasts.

In addition, search operations continue for bodies buried under a thick layer of ash that shrouds whole villages. On Friday, soldiers pulled eight more bodies from around one hard-hit village, said Waluyo Rahardjo, who works for the search and rescue agency.

The Associated Press reports:

Ash has continuously shot out of the crater since it roared to life Oct. 26, occasionally canceling international flights into and out of Jakarta, hundreds of miles (kilometers) to the volcano’s west. After the output slowed overnight, an advisory from the Volcanic Ash Advisory Center in Darwin, Australia, showed the ash patch was well clear of the capital. The airport in Yogyakarta, at the foot of the mountain, however, remained closed.

Officials warned residents that less ash does not mean the volcano is finished.

“The activity of Merapi is still high, but the intensity of eruptions is reducing now. But people still should be careful. Merapi is still on high alert,” said Surano, a state volcanologist who uses only one name.

While officials struggle to persuade hundreds of thousands of people who live on the volcano’s fertile slopes not to return to their homes, a new kind of evacuee has been seen in recent days. Villagers checking on their homes and crops have seen Javan leopards — who live in a national park near the crater — heading down the mountain.

The cats likely feel the continuing tremors, said Tri Prasetyo, who runs the park, and are seeking safer ground. It’s also possible that prey is scarce in areas scorched by searing gases.

Aceng , a Java leopard, released back into the wild. Credit IAR

The Javan leopard — a subspecies of the cat only found on the island of Java — is critically endangered, with no more than 250 left in the wild. Some put the total population as low as 50.

Joko Tirtono, the manager of a zoo in Yogyakarta, said zoo keepers are now searching villages where the leopards have been spotted and laying traps in which they hope to capture the cats alive.

Today is Volcano day – over 1900 years after Pompeii

August 24, 2010

Dr. Erik Klemetti is reporting from Pompeii.

The eruption of Vesuvius that buried Pompeii – and lead Pliny to write his Letters that birthed volcanology occurred (at least we think) on August 24, 79 A.D. So, eat some olives in memory of those who perished over 1,900 years ago – and hope that Naples is prepared the next time Vesuvius rumbles so that we don’t repeat “Volcano Day”.

Pompeii victim:http://www.nationalgeographic.com/history/ancient/images/sw/pompeii-victim-50657432-sw.jpg

Photo: Cast of Pompeii victim

UK University parents emit twice as much CO2 as Ash Cloud Volcano

August 24, 2010

A new study by the UK’s low cost delivery service for students has found that the average fuel cost in the UK for transporting student belongings to and from university is £192 million per year. In total, parents taking their children’s belongings to and from uni emit 291k tonnes of CO2 every year – twice as much CO2 as Iceland’s Eyjafjallajökull volcano; which grounded flights across the world with a giant ash cloud, emitted every day.

http://topics.nytimes.com/top/news/international/countriesandterritories/iceland/eyjafjallajokull/index.html?inline=nyt-geo


The research, commissioned by low cost student baggage delivery service www.UniBaggage.com asked 1,196 parents if they helped their children move their belongings to and from student housing throughout their three years at university. In the academic year of 2008 – 2009 there were 2,396,050 university students in the UK.

The NYT reports that:

Seismic activity is petering out at the volcano that caused major European air-traffic disruption earlier this year, though the eruption has not yet been declared officially over, the authorities in Iceland said Monday. The most serious problem now is posed by mud flows created when heavy rains mix with ash settled along the top of glaciers close to the Eyjafjallajokull (pronounced EY-ya-fyat-lah-YO-kut) volcano, said Sigurlaug Hjaltadottir, a geophysicist with Iceland’s Meteorological Office.

But Eyjafjallajokull’s bigger sister Katla is still due to erupt at any time.

Volcano Katla on Iceland getting ready to erupt?

July 10, 2010

For the last 1000 years eruptions of Eyjafjallajökull on Iceland have always triggered subsequent Katla eruptions. After the ash clouds in the spring caused by the eruptions under Eyjafjallajökul glacier, the region under Katla is rumbling.

There have been 14 earthquakes under the Mýrdalsjökull glacier in the last 48 hours. reported by the Iceland Meteorological Office.

Katla Volcano usually erupts every century, says Iceland’s President Olafur Grimsson. and the last eruption was in 1918. “The time for Katla to erupt is coming close.”

“I don’t say if, but I say when Katla will erupt,” Grimsson says. “We have been waiting for that eruption for several years.”

“It can create, for a long period, extraordinary damage to modern advanced society.”

Map of earthquake epicentres

Significant ash clouds from a Katla eruption could compound the global cooling which has already started. Perhaps we shall soon have another year without a summer!!

Do volcanoes cause climate change?

April 18, 2010

Do volcanoes cause climate change or it the other way around?

Freysteinn Sigmundsson, a vulcanologist at the University of Iceland believes that climate change can impact eruptions. “Global warming melts ice and this can influence magmatic systems,” he told Reuters. The end of the Ice Age 10,000 years ago coincided with a surge in volcanic activity in Iceland, apparently because huge ice caps thinned and the land rose. “We believe the reduction of ice has not been important in triggering this latest eruption,” he said of Eyjafjallajokull. “The eruption is happening under a relatively small ice cap.”

http://www.scientificamerican.com/article.cfm?id=ice-cap-thaw-iceland-volcanoes

But Steven Goddard writing in What’s Up with That suggests it is the other way around.

http://wattsupwiththat.com/2010/04/17/volcanoes-cause-climate-change/#more-18609

Not climate, but perhaps solar effects can impact geological changes in the earth’s crust and influence eruptions. It seems unlikely that a feedback loop from surface air conditions could work to change the earth’s crust.

Clouds and dust from volcanoes can surely affect weather and maybe even weather for a few years. Perhaps volcanoes can even change climate but I think the jury is out on that.


%d bloggers like this: