Iceland Rocked by Thousands of intense earthquakes

This is a Saturday May 8 2010 file image taken from video of a column of ash rising from Iceland's Eyjafjallajokul volcano. 

It was reported Tueday Aug. 19, 2014 that thousands of small intense earthquakes are rocking Iceland amid concerns that one of the country's volcanoes may be close to erupting. 

Iceland has raised its aviation alert level for the risk of a possible volcanic eruption to orange, the second-most severe level. 

The alert is worrisome because of the chaos that followed the April 2010 eruption of Eyjafjallajokul, when more than 100,000 flights were cancelled because volcanic ash floating in the atmosphere is considered an aviation safety hazard. 

Credit: AP Photo/ APTN

Thousands of small intense earthquakes are rocking Iceland amid concerns that one of the country's volcanoes may be close to erupting.

Iceland has raised its aviation alert level for the risk of a possible volcanic eruption to orange—the second-most severe level.

The alert is worrisome because of the chaos that followed the April 2010 eruption of Eyjafjallajokul, when more than 100,000 flights were cancelled because volcanic ash floating in the atmosphere is considered an aviation safety hazard.

Some 3,000 earthquakes have taken place since Saturday in Bárðarbunga (pronounced [b'aurðarbuŋka]), a subglacial stratovolcano located under Iceland's largest glacier.

Iceland's Meteorological Office said that no earthquakes above magnitude 3 have been recorded in the last 24 hours.

Seismologists said Tuesday magma is moving, but it is traveling horizontally.

JAMSTEC: Japan deep sea drilling boat Chikyu casts off to find Earthquakes

Japan's deep-sea drilling vessel Chikyu is anchored at Shimizu port, Shizuoka prefecture on September 11, 2013. 

A Japan-led team of seismologists set off Friday on a mission to drill deep beneath the seabed in a search for the origin of earthquakes.

A Japan-led team of seismologists set off Friday on a mission to drill deep beneath the seabed in a search for the origin of earthquakes.

The scientists weighed anchor on Japan's deep-sea drilling vessel Chikyu, heading for a spot in the ocean off the Kii peninsula, southwestern Japan, and a fracture in the Earth's crust known as the Nankai Trough.

Experts have warned the trough, which marks the place where the Philippine Sea plate slides under the Eurasian plate, is the likely source of a monster earthquake sometime in the near future.

Tamano Omata

Japan's government last year unveiled a worst-case scenario, warning a big quake in the area could kill over 320,000 people, dwarfing the March 11, 2011, quake-tsunami disaster.

In its four-month mission, the latest stage of a multi-year project that began in 2007, the team plans to drill 3,600 metres (2.2 miles) down and take samples from the crust.

They will also be readying for another trip next year in which they hope to get 5,200 metres down, to the spot where the action actually happens.

"It would be unprecedented to drill directly into a seismogenic zone, the area believed to release great energy and cause crusts to slide along fault lines and trigger tsunami," said Tamano Omata, a researcher for the Japan Agency for Marine-Earth Science and Technology (JAMSTEC).

Scientists want to plant sensors—such as seismometers, deformation-measuring devices and thermometers—in the zone, that will form part of a system called Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET), which is linked directly to onshore monitors.

"We expect to become able to monitor how the crusts move immediately before a quake hits," Omata said.

Shinichi Kuramoto

Shinichi Kuramoto, deputy director of JAMSTEC's Center for Deep Earth Exploration, said recent research has shown mild earthquakes, in which the two crusts slip gently past each other, have occurred frequently over stretches of the Nankai Trough in the past five years.

He said it was possible these were precursors to a mega-quake.

"Directly drilling into and observing the place that may release a big quake would be a big step towards understanding the seismological mechanism," he said.

The 56,752-ton Chikyu—"Earth" in Japanese—has been anchored in central Shimizu port, and was open to foreign press this week ahead of the mission.

The vessel, built in 2005 at a cost of $500 million, is equipped with a 121-metre (400-foot) drill tower that can descend 7,000 metres below the seabed, nearly three times as deep as its predecessors.

It depends on satellite location systems with pinpoint accuracy that allow its captain to know exactly where the ship is in relation to the Earth's crust.

Seismically-active Japan experiences 20 percent of the world's major earthquakes every year.

Building standards are high and its people are well-practised at taking cover when quakes strike, meaning damage and death tolls are often much lower than in other parts of the world.

But its proximity to major tectonic faults means the risk is ever-present.

DONET is a submarine cabled real-time seafloor observation infrastructure which was designed to realize precise earthquakes and tsunamis monitoring on seafloor in the long period of time. 

It consists of an approximately 300km length of backbone cable system, 5 science nodes, and 20 observatories. 

Its installation on 20 stations at Kumanonada started in 2006 and has been completed in July 2011.

Studies Link the Rise Of Significant Earthquakes to Oil and Gas extraction

Two new papers tie a recent increase in significant earthquakes to re-injection of wastewater fluids from unconventional oil and gas drilling.

The first study notes “significant earthquakes are increasingly occurring within the United States midcontinent.” In the specific case of Oklahoma, a Magnitude “5.7 earthquake and a prolific sequence of related events … were likely triggered by fluid injection.”

The second study, of the Raton Basin of Southern Colorado/Northern New Mexico by a U.S. Geological Survey (USGS) team, concludes;

”the majority, if not all of the earthquakes since August 2001 have been triggered by the deep injection of wastewater related to the production of natural gas from the coal-bed methane field here.”

Both studies are being presented at the annual meeting of the American Geophysical Union this week.

These studies, together with other recent findings, make a strong case that we need national regulations on wastewater injection to prevent induced earthquakes.

Background
As hydraulic fracturing has exploded onto the scene, it has increasingly been connected to earthquakes. Some quakes may be caused by the original fracking — that is, by injecting a fluid mixture into the earth to release natural gas (or oil).

More appear to be caused by reinjecting the resulting brine deep underground.

In August 2011, a USGS report examined a cluster of earthquakes in Oklahoma and reported:

Our analysis showed that shortly after hydraulic fracturing began small earthquakes started occurring, and more than 50 were identified, of which 43 were large enough to be located. Most of these earthquakes occurred within a 24 hour period after hydraulic fracturing operations had ceased.

In November 2011, a British shale gas developer found it was “highly probable” its fracturing operations caused minor quakes.

In March 2012, Ohio oil and gas regulators said “A dozen earthquakes in northeastern Ohio were almost certainly induced by injection of gas-drilling wastewater into the earth.”

In April, the USGS delivered a paper at the annual meeting of the Seismological Society of America that noted “a remarkable increase in the rate of [magnitude 3.0] and greater earthquakes is currently in progress” in the U.S. midcontinent.

The USGS scientists pointed out that ”a naturally-occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region.”

They concluded:

While the seismicity rate changes described here are almost certainly manmade , it remains to be determined how they are related to either changes in extraction methodologies or the rate of oil and gas production.

The Earth’s Core: An Enigma 1,800 Miles Below Our Feet

Geologists have long known that Earth’s core, some 1,800 miles beneath our feet, is a dense, chemically doped ball of iron roughly the size of Mars and every bit as alien. 

It’s a place where pressures bear down with the weight of 3.5 million atmospheres, like 3.5 million skies falling at once on your head, and where temperatures reach 10,000 degrees Fahrenheit — as hot as the surface of the Sun. 

It’s a place where the term “ironclad agreement” has no meaning, since iron can’t even agree with itself on what form to take. It’s a fluid, it’s a solid, it’s twisting and spiraling like liquid confetti.

Researchers have also known that Earth’s inner Martian makes its outer portions look and feel like home. The core’s heat helps animate the giant jigsaw puzzle of tectonic plates floating far above it, to build up mountains and gouge out seabeds. 

At the same time, the jostling of core iron generates Earth’ magnetic field, which blocks dangerous cosmic radiation, guides terrestrial wanderers and brightens northern skies with scarves of auroral lights.

Now it turns out that existing models of the core, for all their drama, may not be dramatic enough. Reporting recently in the journal Nature, Dario Alfè of University College London and his colleagues presented evidence that iron in the outer layers of the core is frittering away heat through the wasteful process called conduction at two to three times the rate of previous estimates. 

The theoretical consequences of this discrepancy are far-reaching. The scientists say something else must be going on in Earth’s depths to account for the missing thermal energy in their calculations. 

They and others offer these possibilities:

• The core holds a much bigger stash of radioactive material than anyone had suspected, and its decay is giving off heat.
• The iron of the innermost core is solidifying at a startlingly fast clip and releasing the latent heat of crystallization in the process.
• The chemical interactions among the iron alloys of the core and the rocky silicates of the overlying mantle are much fiercer and more energetic than previously believed.
• Or something novel and bizarre is going on, as yet undetermined.

“From what I can tell, people are excited” by the report, Dr. Alfè said. “They see there might be a new mechanism going on they didn’t think about before.”

Researchers elsewhere have discovered a host of other anomalies and surprises. They’ve found indications that the inner core is rotating slightly faster than the rest of the planet, although geologists disagree on the size of that rotational difference and on how, exactly, the core manages to resist being gravitationally locked to the surrounding mantle.

Miaki Ishii and her colleagues at Harvard have proposed that the core is more of a Matryoshka doll than standard two-part renderings would have it. 

Not only is there an outer core of liquid iron encircling a Moon-size inner core of solidified iron, Dr. Ishii said, but seismic data indicate that nested within the inner core is another distinct layer they call the innermost core: a structure some 375 miles in diameter that may well be almost pure iron, with other elements squeezed out. 

Against this giant jewel even Jules Verne’s middle-Earth mastodons and ichthyosaurs would be pretty thin gruel.

Core researchers acknowledge that their elusive subject can be challenging, and they might be tempted to throw tantrums save for the fact that the Earth does it for them. Most of what is known about the core comes from studying seismic waves generated by earthquakes.

As John Vidale of the University of Washington explained, most earthquakes originate in the upper 30 miles of the globe (as do many volcanoes), and no seismic source has been detected below 500 miles. But the quakes’ energy waves radiate across the planet, detectably passing through the core.

Granted, some temblors are more revealing than others. “I prefer deep earthquakes when I’m doing a study,” Dr. Ishii said. “The waves from deep earthquakes are typically sharper and cleaner.”

Read more of this article here: Earth’s Core - The Enigma 1,800 Miles Below Us

ESA ENVISAT: Earth movements from Japan earthquake

Envisat Advanced Synthetic Aperture Radar coseismic interferogram from descending track 347, processed by JPL/Caltech ARIA project. Data acquired on 19 February and 21 March 2011, spanning the main shock of the magnitude 9 earthquake and several aftershocks that occurred in Japan on 11 March 2011 and the following days (until 21 March).

One colour cycle represents 50 cm of motion in the satellite line of sight (approximately east at 41 degrees from the vertical), i.e. about 35 cm of motion on the ground. The seismicity plot is from the US Geological Survey.

Credits: Based on ESA data - JPL/Caltech ARIA project (E. Fielding, Principal Scientist JPL/Caltech; S. Yun, Research Scientist JPL/Caltech; P. Agram, KISS Postdoctoral Fellow Caltech)

Japanese Tsunami: Fukushima No 3 reactor building explosion

An explosion rocked an earthquake-hit nuclear plant Monday, as Japan struggled to avert a catastrophic reactor meltdown caused by a quake and tsunami feared to have killed more than 10,000.

A new tsunami scare triggered evacuations on the devastated northeast coast after a large wave was spotted rolling in to shore, but authorities said they had detected no sign of a tsunami or a quake that would have caused it.

Japan has been battling to control two overheating reactors at the ageing Fukushima plant after the cooling systems were knocked out by Friday's 8.9-magnitude quake and the resulting tsunami that swallowed up whole towns.

Shortly after Prime Minister Naoto Kan said the plant was still in an "alarming" state, a blast at its number-three reactor shook the facility and sent plumes of smoke billowing into the sky.

The plant's operator TEPCO said that nine people were injured in the blast, which authorities said was probably a hydrogen explosion.

The chief government spokesman Yukio Edano said TEPCO reported that the reactor was probably undamaged and there was a low possibility of a major radiation leak at the plant, 250 kilometres (160 miles) northeast of Tokyo.

Another explosion blew apart the building surrounding the plant's number-one reactor on Saturday but the seal around the reactor itself remained intact.

Powerful quake strikes near Solomon Islands

Powerful quake strikes near Solomon Islands

A powerful 7.2 magnitude earthquake struck near the Solomon Islands in the western Pacific on Monday, triggering panic and causing some damage but no major tsunami, officials said.

Several houses collapsed, leaving a number of people homeless, and some tourists reportedly suffered minor injuries, disaster officials said, after a series of tremors shook the area.

The US Geological Survey said the epicentre of the biggest quake was about 103 kilometres from the earthquake-prone island town of Gizo, measured at a depth of about 30 kilometres (19 miles).

It was the largest of a swarm of tremors centred on the area, ignited by a 6.5 magnitude quake early on Monday and followed several hours later by aftershocks of magnitude 5.3 and 5.2 and 5.7

On the tiny island of Rendova, near Gizo, several houses collapsed but there were no other reports of damage, Julian Makaa of the National Disaster Management Office told AFP.

"The earthquake caused a small wave, and a few people suffered minor injuries as they ran away from the shore in panic," he said.

Tajikistan quake leaves 10,000 without shelter: officials

Tajikistan quake leaves 10,000 without shelter: officials

An earthquake in the Pamir mountains of Tajikistan has destroyed hundreds of homes, leaving some 10,000 people without shelter in the dead of winter, officials said Sunday.

"According to preliminary information, 300 houses have been destroyed," a regional spokesman for the country's Civil Defense Committee responsible for the affected area told AFP.

Some 10,000 people have been left without shelter as scores of other homes have been damaged, the spokesman said, citing preliminary information.

Two schools, a clinic and a power line have also been destroyed, he added.

The spokesman reported no deaths but said dozens of sheep and goats were killed in the earthquake that struck around ten high-altitude villages in the Pamir mountains in eastern Tajikistan on Saturday.

The US Geological Survey reported that a 5.3-magnitude earthquake struck 235 km (145 miles) east of the Tajik capital Dushanbe at 07:15 a.m. (0215 GMT) on Saturday. It had a depth of 44.5 km (27.7 miles), the survey said.

Authorities said they were assessing damages, but their work was complicated by the location of the destroyed villages. More than 25,000 people live in the affected area, the Vanj district.

Sun, moon causing tremors deep in San Andreas fault

The faint tug of the sun and moon on the San Andreas Fault stimulates tremors deep underground, suggesting that the rock 15 miles below is lubricated with highly pressurized water that allows the rock to slip with little effort, according to a new study by University of California, Berkeley, seismologists.

"Tremors seem to be extremely sensitive to minute stress changes," said Roland Burgmann, UC Berkeley professor of earth and planetary science. "Seismic waves from the other side of the planet triggered tremors on the Cascadia subduction zone off the coast of Washington state after the Sumatra earthquake last year, while the Denali earthquake in 2002 triggered tremors on a number of faults in California. Now we also see that tides - the daily lunar and solar tides - very strongly modulate tremors."

In a paper appearing in the Dec. 24 issue of the journal Nature, UC Berkeley graduate student Amanda M. Thomas, seismologist Robert Nadeau of the Berkeley Seismological Laboratory and Burgmann argue that this extreme sensitivity to stress - and specifically to shearing stress along the fault - means that the water deep underground is under extreme pressure.

"The big finding is that there is very high fluid pressure down there, that is, lithostatic pressure, which means pressure equivalent to the load of all rock above it, 15 to 30 kilometers (10 to 20 miles) of rock," Nadeau said. "Water under very high pressure essentially lubricates the rock, making the fault very weak."

Though tides raised in the Earth by the sun and moon are not known to trigger earthquakes directly, they can trigger swarms of deep tremors, which could increase the likelihood of quakes on the fault above the tremor zone, the researchers say. At other fault zones, such as at Cascadia, swarms of tremors in the ductile zone deep underground correlate with slip at depth as well as increased stress on the shallower "seismogenic zone," where earthquakes are generated. The situation on the San Andreas Fault is not so clear, however.

"These tremors represent slip along the fault 25 kilometers (15 miles) underground, and this slip should push the fault zone above in a similar pattern," Burgmann said. "But it seems like it must be very subtle, because we actually don't see a tidal signal in regular earthquakes. Even though the earthquake zone also sees the tidal stress and also feels the added periodic behavior of the tremor below, they don't seem to be very bothered."

Nevertheless, said Nadeau, "It is certainly in the realm of reasonable conjecture that tremors are stressing the fault zone above it. The deep San Andreas Fault is moving faster when tremors are more active, presumably stressing the seismogenic zone, loading the fault a little bit faster. And that may have a relationship to stimulating earthquake activity."

Seismologists were surprised when tremors were first discovered more than seven years ago, since the rock at that depth - for the San Andreas Fault, between 15 and 30 kilometers (10 to 20 miles) underground - is not brittle and subject to fracture, but deformable, like peanut butter. They called them non-volcanic tremors to distinguish them from tremors caused by fluid - water or magma - fracturing and flowing through rock under volcanoes. It was not clear, however, what caused the non-volcanic tremors, which are on the order of a magnitude 1 earthquake.

To learn more about the source of these tremors, UC Berkeley seismologists began looking for tremors five years ago in seismic recordings from the Parkfield segment of the San Andreas Fault obtained from sensitive bore-hole seismometers placed underground as part of the UC Berkeley's High-Resolution Seismic Network. Using eight years of tremor data, Thomas, Burgmann and Nadeau correlated tremor activity with the effects of the sun and moon on the crust and with the effects of ocean tides, which are driven by the moon.

They found the strongest effect when the pull on the Earth from the sun and moon sheared the fault in the direction it normally breaks. Because the San Andreas Fault is a right-lateral strike-slip fault, the west side of the fault tends to break north-northwestward, dragging Los Angeles closer to San Francisco.