Posts Tagged ‘Earthquake’

Images of new island born after earthquake in Pakistan

September 28, 2013

A second earthquake (6.8 magnitude) rocked south-west Pakistan today, in a region where at least 400 people died in a 7.7 magnitude quake earlier this week. The earlier quake gave birth to a new island off the coast of Gwadar.

Map locator

The epicentre of Tuesday’s quake, which hit close to the location of the latest seismic shock. BBC

From NASA’s Earth Observatory:

On September 24, 2013, a major strike-slip earthquake rattled western Pakistan, killing at least 350 people and leaving more than 100,000 homeless. The 7.7 magnitude quake struck the Baluchistan province of northwestern Pakistan. Amidst the destruction, a new island was created offshore in the Paddi Zirr (West Bay) near Gwadar, Pakistan.

On September 26, 2013, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured the top image of that new island, which sits roughly one kilometer (0.6 miles) offshore. Likely a mud volcano, the island rose from the seafloor near Gwadar on September 24, shortly after the earthquake struck about 380 kilometers (230 miles) inland. The lower image, acquired by the Operational Land Imager on the Landsat 8 satellite, shows the same area on April 17, 2013.

Earthquake Births New Island off Pakistan

acquired September 26, 2013 – Earthquake Births New Island off Pakistan

Coast of Gwadar acquired April 17, 2013

The aerial photograph below from the National Institute of Oceanography provides a close-up of the landform, estimated to stretch 75 to 90 meters (250 to 300 feet) across and standing 15 to 20 meters (60 to 70 feet) above the water line. The surface is a mixture of mud, fine sand, and solid rock.

Aerial view of new island acquired September 26, 2013

“The island is really just a big pile of mud from the seafloor that got pushed up,” said Bill Barnhart, a geologist at the U.S. Geological Survey who studies earthquakes in Pakistan and Iran. “This area of the world seems to see so many of these features because the geology is correct for their formation. You need a shallow, buried layer of pressurized gas—methane, carbon dioxide, or something else—and fluids. When that layer becomes disturbed by seismic waves (like an earthquake), the gases and fluids become buoyant and rush to the surface, bringing the rock and mud with them.”

Inam asserted that the underground pressure in this case came from expanding natural gas. “The main driving force for the emergence of islands in this part of the world is highly pressurized methane gas, or gas hydrate. On the new island, there is a continuous escape of the highly flammable methane gas through a number of vents.”

Several of these islands have appeared off the 700-kilometer-long Makran coast in the past century noted Eric Fielding, a tectonics scientist at NASA’s Jet Propulsion Laboratory. He explained that the Makran coast is where the Arabian tectonic plate is pushed northward and downward to go underneath the Eurasian continental plate. The thick layer of mud and rock on the Arabian Plate is scraped off and has formed the land in southwestern Pakistan, southeastern Iran, and the shallow underwater area offshore.

“The Makran coast is not very populated and any such event may easily go unnoticed, so satellite images are extremely important,” Inam said. “Mud volcanoes and islands are a natural hazard and threat to navigation.”

The life of this island is likely to be short. That underground pocket of gas will cool, compress, or escape over time, allowing the crust to collapse and settle back down. Waves, storms, and tidal action from the Arabian Sea will also wash away the loose sand, soft clay, and mud. Barnhart says such islands usually last a few months to a year before sinking back below the water line.

Earthquakes release methane from methane hydrates

July 29, 2013

“Natural” release of methane from methane hydrates by earthquakes is more common and more significant than has been thought or accounted for in climate models.

The inescapable conclusion is that effects  being attributed by the demonisation of carbon to man made carbon dioxide emissions (even if real) may well be partly due to the natural release of such methane.  The global temperature pause for the last 17 years or so and the clear but small decline in global temperatures for the last 5 years is quite clear. At the same time emissions from fossil fuel combustion have been steadily increasing. These are a clear indication that the supposed linkage between carbon dioxide concentration and man-made carbon dioxide emissions on climate is very suspect if not completely broken.

It is also becoming increasingly clear that climate models – even though very complicated – are far too simplistic and just don’t (can’t) take all factors into account. Clouds, aerosols, particulates, solar effects, lunar cycle effects through the tides, ocean cycles and now earthquakes are all poorly understood and largely ignored in climate models. There is far more in the realms of the unknown about the climate than is known. We don’t even know what we don’t know.

David Fischer, José M. Mogollón, Michael Strasser, Thomas Pape, Gerhard Bohrmann, Noemi Fekete, Volkhard Spiess & Sabine Kasten, Subduction zone earthquake as potential trigger of submarine hydrocarbon seepage, Nature Geoscience (2013) doi:10.1038/ngeo1886

Here we present geochemical analyses of sediment cores retrieved from the convergent margin off Pakistan. We find that a substantial increase in the upward flux of gas occurred within a few decades of a Mw 8.1 earthquake in 1945—the strongest earthquake reported for the Arabian Sea. Our seismic reflection data suggest that co-seismic shaking fractured gas-hydrate-bearing sediments, creating pathways for the free gas to migrate from a shallow reservoir within the gas hydrate stability zone into the water column. We conservatively estimate that 3.26×108 mol of methane have been discharged from the seep site since the earthquake. We therefore suggest that hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins.

New York Times:

Dr. Fischer and his colleagues analyzed sediment cores taken in 2007 from two locations in the northern Arabian Sea where hydrates were present and seepage was occurring. They found chemical signatures in the cores suggesting that the methane flow greatly increased sometime in the mid-20th century. Looking through seismic records, Dr. Fischer found that a magnitude 8.1 quake occurred in the area in 1945. The quake, which was centered less than 15 miles from where the cores were taken, and a resulting tsunami, killed up to 4,000 people.

The conclusion was inescapable, Dr. Fischer said. “The quake broke open gas-hydrate sediments and the free gas underneath migrated to the surface.” The hydrates themselves did not dissolve. “They remain there,” he said.

Dr. Fischer said the researchers chose the core locations in the Arabian Sea because they wanted to get a better understanding of how methane seepage was related to tectonics, and the area is in an active zone where one of the earth’s tectonic plates slides beneath another. But they were not thinking about the effect of individual earthquakes, and his discovery of the 1945 quake in the records “was probably a moment I’ll never forget,” he said.

The upward flow of methane is continuing today, and the researchers do not know when it might stop. All told, they estimate that nearly 10 million cubic yards of methane have been released from the core sites over the years. But that is a conservative figure, Dr. Fischer said, because immediately following the quake the flow would have been much higher.

 

Durham University finds that fracking is not very significant in causing tremors

April 10, 2013

The fears of earthquakes and water contamination are being wildly exaggerated by all those who would prevent the hydraulic fracturing (fracking) of the vast deposits of gas shale available around the world. But research at the University of Durham puts the threat of micro-seismsity into perspective.

BBC reports:

New research suggests that fracking is not a significant cause of earthquakes that can be felt on the surface. UK scientists looked at quakes caused by human activity ranging from mining to oil drilling; only three could be attributed to hydraulic fracturing.

Most fracking events released the same amount of energy as jumping off a ladder, the Durham-based team said. They argue that the integrity of well bores drilled for fracking is of much greater concern.

The research is published in the Journal of Marine and Petroleum Geology.

 …. Fracking, as it is called, utilises a mixture of water, sand and chemicals pumped underground at high pressure to crack open sedimentary rocks and release the fuels within. But opponents of fracking have long been concerned that the process could induce earthquakes such as the one that occurred near a shale gas operation in Lancashire in 2011.

Now researchers from Durham University’s Energy Institute say that the pumping of fracking liquid does indeed have the potential to reactivate dormant fault lines. But they say that compared to many other human activities such as mining or filling reservoirs with water, fracking is not a significant source of tremors that can be felt on the surface.

“We’ve looked at 198 published examples of induced seismicity since 1929,” Prof Richard Davies from Durham told BBC News. “Hydraulic fracturing is not really in the premier league for causing felt seismicity. Fundamentally it is is never going to be as important as mining or filling dams which involve far greater volumes of fluid.” The researchers detailed just three incidences of earthquakes created by fracking – one each in the US, the UK and Canada. The biggest at Horn River Basin in Canada in 2011 had a magnitude of 3.8.

“Most fracking related events release a negligible amount of energy roughly equivalent to, or even less than someone jumping off a ladder onto the floor,” said Prof Davies. ….. 

 

Swarm of 482 earthquakes (so far) in Iceland

April 2, 2013

Something to watch closely over the next few days. Could a new island be forming?

UPDATE2: 04 Apr 18:57 GMT

The aviation colour code for Hekla volcano has been changed from yellow to green as no further signs of unrest have been detected since it was changed to yellow. The activity in North Iceland has been decreasing today. The activity could still continue for a some time with intense activity in between.

UPDATE: A M5.5 earthquake occurred at 00:59 on 2nd April 2013 about 15 km east of Grímsey island offshore North Iceland. The earthquake was felt at Grímsey, Húsavík, Raufarhöfn, Mývatnssveit, Akureyri and Sauðarkrókur. Several hundruds aftershocks have been detected following the mainshock. The source region is located on a fault system that reaching from Öxarfjörður to the north of Grímsey, the so called Grímsey lineament. Another M4.7 earthquake followed this morning at 08:56 and was located about 7.5km northwest of the night’s main event.

Earthquake sequences are common in this area. It is impossible to predict the further development of the seismic activity and how it might influence faults in its vicinity. Further large events can not be excluded.

==========================================

The Iceland earthquake swarm has now reached a count of 482 according to the Icelandic Met Office.

  • Magnitude less than 1 in all:  39
  • Magnitude 1 to 2 in all:  173
  • Magnitude 2 to 3 in all:  232
  • Magnitude more than 3 in all:  38
  • Total: 482 (upto 712 on 3rd April)
Earthquakes during last 48 hours.  at 04 Apr 19:50 GMT

Earthquakes during last 48 hours. at 04 Apr 19:50 GMT

From Earthquake Report:

Update 10:49 UTC : We have added a Google Earth screenshot to the image series. This Google earth image shows very clearly the many volcanic bubbles at the ocean floor, a result of the separating diverging plates. The 2 tectonic plates are pullling away from each other  (left plate to the West, right plate to the East. This kind of phenomenon is also occurring in the Oceans all over the world. New life (in other words new magma) is added this way to the tectonic plates. The plates are melting away again below ie. the deep trenches of the Pacific Ocean.

Update 10:12 UTC : The Icelandic seismological Bureau wrote : At 00:59 an earthquake about 5.5 occurred, 15 km east of Grímsey. the earthquake was felt in substantial part of central north Iceland. Following the this event at 1:13 another earthquake 4,3 was observed 16 km east of Grímsey and at 08:55 an earthquake 4,7 at same location. Substantial aftershock activity has been observed and still continues. More activity can be expected.

This earthquake is part of a strong swarm at a well know location in the Ocean. The location of the swarm is a relatively shallow ridge area (the zigzagging ridge creates the transform-like earthquakes) . A ridge is a location where 2 tectonic plates are pulling away from each other. Fresh magma will have an easier job to reach the seabed and hot volcanic vents are often found on these locations. A new island in such an area is almost a certainty in the geological future. A pity that there are no permanent ROV’s in this location, we might see some submarine fireworks!
At the time of writing this article, we have counted 314 earthquakes in less than 48 hours!

Screen Shot 2013-04-02 at 12.48.02

Swarm area on Google Earth

Icleand lifts Hekla alert to yellow

March 26, 2013

For the first time in two years the Iceland Meteorological Office has raised the aviation warning code for Mount Hekla from green to yellow due to unusual seismic activity around the volcano. Seven minor seismic events have occurred since 10th March and these are considered abnormal around Hekla. Hekla has erupted 20 times since 874 CE and erupted last in 2000 and previously – in recent times – in 1991, 1981,1980, 1970 and 1947.

The Icelandic Meteorological Officehas changed the aviation colour-code of Hekla volcano from green to yellow, signifying elevated unrest above a known background level during the last weeks. The Icelandic Civil Defence together with the Police in Hvolsvöllur have declared a level of uncertainty for Hekla. The change from green to yellow is a precautionary step due to increased earthquake activity. To date, there are no observable signs that an eruption of Hekla is imminent.

location of iceland volcanos (from decadevolcano.net)

8.7 magnitude earthquake off Aceh again – tsunami watch

April 11, 2012

Update: A small tsunami (17cm) is reported to be heading towards the Aceh coast but the US Geological Survey believes the risk for a large tsunami is small. A tsunami “warning” is in effect in Sri Lanka and the eastern coast of India. Tremors were felt 1500km away across Southern India; in Chennai, Bangalore and Thiruvananthapuram among many other cities.

Breaking!

Indonesia issued a tsunami warning Wednesday after an earthquake with a preliminary magnitude of 8.7 hit waters off westernmost Aceh province. tremors were felt in Singapore, Thailand, Malaysia and India. High-rise apartments and offices on Malaysia’s west coast shook for at least a minute.

The Pacific Tsunami Warning Center in Hawaii said a tsunami watch was in effect for Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, the Maldives and other Indian Ocean islands, Malaysia, Pakistan, Somalia, Oman, Iran, Bangladesh, Kenya, South Africa and Singapore. …

A giant 9.1-magnitude quake off the country on Dec. 26, 2004, triggered a tsunami in the Indian Ocean that killed 230,000 people, nearly three quarter of them in Aceh.

Interestingly the Piers Corbyn’s March forecast for extreme weather (based on solar activity) had identified 8th – 10th April as being especially prone to severe earthquake or volcanic activity.

article image

extract from the Piers Corbyn March Earthquake & Major Volcano Red Warning chart published in March, the period 8th - 10th April was highlighted as a Top Red Warning (R4) period

One year on from the Great Tohoku earthquake and tsunami

March 11, 2012

One year on and young hopes bloom eternal.

Illustration by Yuko Shimizu

Young hopes bloom eternal: Illustration by Yuko Shimizu: From The Japan Times

I was in Japan during the Great Hanshin Earthquake in 1995 when over 6,000 perished in Kobe and – inevitably – I try to relate events to my own experience. But the Graeat Tohuku earthquake and tsunami were something quite different and have claimed more than 20,000 lives.

The death toll was much greater after the Aceh earthquake and tsunami but was spread over many more countries and in that sense is more “diffuse”. Perceptions sometimes get diluted compared to the intensity of the reactions one year ago. The 2004 Indian Ocean earthquake and tsunami claimed over 230,000 lives in 14 countries.

The meltdowns at the Fukushima nuclear plant following the Tohoku earthquake and tsunami were pretty scary but sometimes the coverage (especially in Europe) becomes alarmist and tends to take away from the earthquake and tsunami. But it is worth remembering also that the incidents at Fukushima  – without trying to trivialise them – have caused no radiation related deaths.

Further twists in the Italian manslaughter trial of seismologists

February 21, 2012
L'Aquila house ruin

A panel of seismologists who met just days before the 2009 earthquake in L’Aquila, Italy are on trial over their reassurances to the public. WOLFANGO VIA FLICKR UNDER CREATIVE COMMONS.

Back in September when this trial for manslaughter began, many rushed to the defence of the scientists being indicted as being an “attack on science”. I wrote then that indictments for incompetence or negligence or even gross negligence by scientists  should not be confused with being an indictment of the scientific method. Scientists are in a privileged position but that does not mean that they cannot be liable for their incompetence. As the trial lumbers on it becomes clearer that there was indeed some considerable incompetence involved. Now Nature reports that a Californian scientist and earthquake expert is testifying against the defendents:

….. The hearing also included some true scientific debate when Lalliana Mualchin, former chief seismologist for the Department of Transportation in California, testified as an expert witness for the prosecution. In 2010, when news about the indictment broke, Mualchin was among the few experts who openly criticized — and refused to sign — a letter supporting the indicted seismologists signed by about 5,000 international scientists.

(more…)

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

Scientific negligence goes on trial for manslaughter in Italy

September 20, 2011

“Scientists” today enjoy a general reputation for being unbiased, objective, incorruptible and dauntless seekers after truth. With this reputation they also have little liability for their pronouncements or for the integrity or the quality of their work. This is not sustainable as the politicisation of science is increasingly unavoidable and temptations for scientific misconduct grow. To try and de-politicise science is impractical. More emphasis can be placed on developing ethical standards which should reduce the incidence of misconduct. But I think the key is to ensure that scientists carry some liability for what they do and that they do it honestly. A scientist is no less a professional than a lawyer or an engineer or a physician or an architect. They do have some liability for the quality of what they do. Incompetence, negligence or dishonesty carry penalties for other professions and scientists can not and should not be exempt.

Of course the scientific community is up in arms about the seismologists being tried for manslaughter in Italy, but they do need to be held accountable for their negligence or incompetence – if demonstrated. Wearing a white coat and calling oneself a “scientist” should not provide automatic immunity from accountability and liability.

Scientific American:  By Nicola Nosengo

Six Italian seismologists and one government official will be tried for the manslaughter of those who died in the earthquake that struck the city of L’Aquila on 6 April 2009. The seven were on a committee that had been tasked with assessing the risk associated with recent increases in seismic activity in the area. Following a committee meeting just a week before the quake, some members of the group assured the public that they were in no danger. 

In the aftermath of the quake, which killed 309 people, many citizens said that these reassurances were the reason they did not take precautionary measures, such as leaving their homes. As a consequence, the public prosecutor of L’Aquila pressed manslaughter charges against all the participants in the meeting, on the grounds that they had falsely reassured the public. After several delays, the public prosecutor Fabio Picuti and the defendants’ lawyers appeared this week before Giuseppe Gargarella, the judge for preliminary hearings, who had to decide whether to dismiss the case or proceed with a trial.

During the hearing, the prosecutor called the committee’s risk assessment “superficial and generic”, resulting in “incomplete, imprecise and contradictory public information”. Responding to the thousands of scientists who had signed a letter of support for the defendants, the prosecutor acknowledged that the committee members had no way of predicting the earthquake, but he accused them of translating their scientific uncertainty into an overly optimistic message. More specifically, the accusation focuses on a statement made at a press conference on 31 March 2009 by Bernardo De Bernardinis, who was then deputy technical head of Italy’s Civil Protection Agency and is now president of the Institute for Environmental Protection and Research in Rome. “The scientific community tells me there is no danger,” he said, “because there is an ongoing discharge of energy. The situation looks favorable”. ….

 At the end of the hearing, the judge decided that the trial will begin on 20 September. …

The earthquake was surely not predictable and poor building standards surely contributed to the deaths but whether the scientists exhibited incompetence or negligence is a valid question. And if they did they need to be held accountable even if not perhaps for manslaughter.


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