Saturday, October 12, 2013

PLANETARY TREMORS: Concrete Risks - Major Earthquake Would Collapse Over A Thousand Buildings In Los Angeles!

October 12, 2013 - UNITED STATES - More than 1,000 old concrete buildings in Los Angeles and hundreds more throughout the county may be at risk of collapsing in a major earthquake, according to a Times analysis.

By the most conservative estimate, as many as 50 of these buildings in the city alone would be destroyed, exposing thousands to injury or death.




A cross-section of the city lives and works in them: seamstresses in downtown factories, white-collar workers in Ventura Boulevard high-rises and condo dwellers on Millionaires' Mile in Westwood.

Despite their sturdy appearance, many older concrete buildings are vulnerable to the sideways movement of a major earthquake because they don't have enough steel reinforcing bars to hold columns in place.

Los Angeles officials have known about the dangers for more than 40 years but have failed to force owners to make their properties safer. The city has even rejected calls to make a list of concrete buildings.

In the absence of city action, university scientists compiled the first comprehensive inventory of potentially dangerous concrete buildings in Los Angeles.

The scientists, however, have declined to make the information public. They said they are willing to share it with L.A. officials, but only if the city requests a copy. The city has not done so, the scientists said.

Recent earthquakes have spotlighted the deadly potential of buildings held up by concrete. A 2011 quake in Christchurch, New Zealand, more than two years ago toppled two concrete office towers, killing 133 people. Many of the 6,000 people killed in a 1995 earthquake in Kobe, Japan, were in concrete buildings.





In 1971, the Sylmar earthquake brought down several concrete structures, killing 52. Twenty-three years later, the Northridge earthquake wrecked more, including a Bullock's department store and Kaiser medical office.

Seismologists said a bigger quake is overdue.

"We know darn well that if a bunch of people die, there will be lots of stories, lots of reports, things will change," said Thomas Heaton, director of Caltech's Earthquake Engineering Research Laboratory. "But the question is, do we have to have lots of people die in order to make this change?"

In the Roaring '20s, concrete buildings helped transform the Los Angeles skyline, as office towers and apartments rose from the city's landscape.

By the 1970s, canyons of concrete towers lined some of L.A.'s most famous streets: Wilshire, Hollywood, Sunset, Ventura, Main and Broadway. They include landmarks such as the Capitol Records tower, the Hollywood Plaza apartments and the W Hotel in Westwood, according to city records.

A team of Times reporters mined thousands of city and county records to identify older concrete buildings. The Times found more than 1,000 buildings in Los Angeles and hundreds elsewhere in the county that appeared to be concrete.

Reporters walked through seven L.A. business districts to gauge the accuracy of the list. They pulled building permits and sent questionnaires to dozens of property owners, asking them to review the details. In these areas, The Times found 68 older concrete buildings, according to public records. Of those, just seven had been retrofitted, or strengthened to survive large earthquakes. The reporters' work covered a fraction of the older concrete structures in the city.





The survey showed the difficulties of accurately identifying concrete buildings. Some city records didn't specify the construction materials used. Some buildings that appeared to be made of concrete turned out to be steel framed, while others that appeared to be brick or steel were concrete.

Hollywood — which is bisected by a fault capable of producing a 7.0 earthquake — has one of the biggest concentrations of concrete buildings. In a few blocks around Hollywood Boulevard and Vine Street, The Times found 14 concrete structures built before 1976, when city codes started requiring more steel rebar. Only three have been retrofitted.

The story is much the same on a stretch of Ventura Boulevard in the Encino area. The Northridge quake battered several concrete buildings in the district, including a 10-story hotel. Owners spent $4 million to better protect it in an earthquake. Out of 10 concrete buildings on that section of the street, only the hotel and one other structure have been strengthened.

In two downtown neighborhoods, along Broadway and Santee Street, The Times found 17 concrete buildings. None had a record of retrofitting.

One of those buildings is owned by Scott Kim's family. When they bought the five-story factory for their sewing supply business, Kim said, they didn't think to have it examined by a structural engineer.

"It went through other earthquakes, and it's still here," said Kim, whose family paid $5 million for the property a decade ago. "I know back in the day they built buildings much sturdier than buildings today."

Charles Tan, an engineer who has helped retrofit downtown buildings, warned that surviving past earthquakes doesn't mean the structure is safe.

"I've had that said to me quite often: 'Look, this building looks good, has no cracks, no damage,'" Tan said. "A lot of these buildings haven't, at least these specific ones in downtown haven't been tested yet with a high-magnitude earthquake in this exact vicinity."





Owners might be unaware of the risks, but city officials have been warned repeatedly about the dangers of concrete buildings since 1971.

That year, the Sylmar quake shattered two concrete structures at the 46-year-old Veterans Administration Hospital in San Fernando. The three-story buildings pancaked when the concrete crumbled, leaving the red tile roof smashed on the ground. Many patients were crushed under the debris; 49 people died.

Seismic experts were more alarmed by Olive View Medical Center in Sylmar, which had opened just months before and was built using stricter codes. The five-story hospital lurched sideways when some of its first-floor columns broke. Three concrete stairwells toppled. A two-story psychiatric building collapsed. Three people died.

After Sylmar, L.A. officials beefed up seismic codes for new buildings, requiring more steel inside concrete columns to prevent chunks from breaking away. The extra steel acts like a cage, keeping the concrete in place, even if the column cracks.

But structures built before the mid-1970s remained at risk because many lack adequate steel rebar and can't bend. Engineers call these buildings "non-ductile."

When more concrete buildings fell in the 1994 Northridge earthquake, Los Angeles Councilman Hal Bernson and Karl Deppe, a top city building official, decided the time was right to push for tougher retrofitting laws.

Their proposal called for creating a list of all vulnerable buildings across the city, including concrete ones. Property owners would be required to prepare a plan to strengthen them.

"It would be criminal" not to pursue mandatory retrofitting, Deppe said at the time.

Bernson and others had reason to hope. They had successfully pushed the city a decade earlier to require property owners to retrofit or demolish about 8,000 brick buildings. But Los Angeles was still recovering from a recession after the Northridge quake, and then-Mayor Richard Riordan didn't want to burden businesses with more regulations. Bernson's proposal eventually died. Officials instead settled on a voluntary retrofitting program.

"There's two sides: There's the human risk. There's the financial risk," Bernson said in a recent interview. "To me, there was never any question about the two. The question of human life was always more important than financial."

In the early 2000s, retired building officials tried again to make City Hall focus on concrete dangers. Nothing happened.

Greig Smith, Bernson's former chief of staff, tried twice to revive the issue after he was elected to the City Council in 2003. Both attempts failed. He proposed an alternative: Identify concrete buildings and label the hazardous ones. That failed too.


David Lee's sewing business occupies part of a building in downtown L.A. To determine whether a
building needs retrofitting, owners would have to spend as much as $100,000 on a structural study.
(Mel Melcon / Los Angeles Times)



Property owners have been the biggest opponent of retrofitting rules. Even posting warning signs "scared the heck out of" them, Smith said in an interview.

Many owners say they shouldn't have to pay for expensive fixes on their own.

"The cost of doing this would be greater than the value of the building, and that didn't make sense to us," said Carol Schatz, president and chief executive of the Central City Assn.

Researchers who study how concrete buildings fare in earthquakes say 5% of these structures typically collapse. In Los Angeles, that would be at least 50 buildings.

Many more need retrofitting. Nabih Youssef, an engineer who helped strengthen City Hall, the Coliseum and other prominent L.A. structures, said that based on his experience, about 30% of older concrete buildings require major work. Others believe the number is much higher.

To determine whether a building needs retrofitting, owners would have to spend as much as $100,000 on a structural study that ascertains what is inside the columns.

They would have to hire engineers who might install angled steel beams to provide more support, like an exoskeleton. Another solution could be the addition of sturdy interior concrete walls that stretch from the ground to the roof. The fixes could cost $1 million or more. Occupants probably would have to move out during the renovation, at an additional cost.

"Will it be better safety-wise if you reinforce this? Will you help save lives? Yes," said Martha Cox-Nitikman of the Building Owners and Managers Assn. of Greater Los Angeles. "But that's easy to say — if you have money."

In 2006, the university researchers stepped in.

Backed by a $3.6-million grant from the National Science Foundation, a team led by UC Berkeley engineering professor Jack Moehle set out to produce a list of older concrete buildings that might collapse during a major earthquake.

When he and his team embarked on the mission, Moehle declared that "existing vulnerable buildings are the No. 1 seismic safety problem in the world." They hoped their research would "save thousands of lives."


Concrete columns supporting the stairwells of Olive View Medical Center failed because there was too
little steel reinforcement. After the 1971 Sylmar earthquake, county officials toured the destruction.
(John Malmin / March 4, 1971)

Over the next seven years, Moehle's team identified about 1,500 potentially vulnerable concrete buildings in Los Angeles through public records and their own walking survey. The list was designed to be a first step. Each building would have to be examined more thoroughly to determine whether it needed strengthening.

Moehle declined to give the list to The Times, saying his team could be exposed to legal liability from building owners because the data are far from definitive.

"I don't want to get sued. It's that simple," said Moehle, adding that he would "probably" give it to the city if asked. "It would be their responsibility to figure out what to do with it."

Advocates said the list would give the city a head start in tackling the concrete problem.

"You need to get an elected official who is willing to stick his neck out and take the leadership role," Bernson said.

A spokesman for Mayor Eric Garcetti said he is interested in The Times' report and would review the issue.

Without action from the city, retrofitting has been limited. As downtown and Hollywood gentrified, developers were required to retrofit concrete buildings when converting old office towers and warehouses into residences. Others strengthened their buildings, pressured by lenders or insurers.

Seismologists and engineers say time is running out to fix dangerous concrete buildings.

If the Big One hits the San Andreas fault — and scientists say it's long overdue — seismic waves would cascade into downtown Los Angeles at a magnitude not felt since 1857. Another alarming scenario is a huge temblor striking directly underneath Hollywood or the Westside. More than 300 faults crisscross the L.A. Basin.

Past earthquakes have sparked billions of dollars in retrofitting in the state, with proven results.

Hundreds of state bridges and freeway overpasses have been replaced or retrofitted; all but two are completed. Public and private universities have voluntarily overhauled concrete buildings. State earthquake regulations for hospitals have led to safer, modernized medical buildings.

Los Angeles' 1981 law requiring retrofitting of 8,000 brick buildings saved lives: Although 60 people died in the Northridge quake, none were in brick structures.

But, as structural engineers reported to the state after the Northridge earthquake, the collapse of a single concrete building "has the potential for more loss of life than any other catastrophe in California" since the 1906 San Francisco earthquake.

Earthquake safety has rarely been an issue that draws deep public passions and outrage. Most seismic regulations are approved in the wake of destructive earthquakes, but there hasn't been one in California in nearly 20 years.

"Just like accidents, fires, we don't know when the big earthquake will come," said Yolanda Elizon, a maid for low-income elderly residents at the 10-story Hollywood Plaza Apartments. "I believe if the earthquake comes, only God can save us."

Without a government mandate to fix old concrete buildings, owners are left to make their own judgments about safety.

Ethan Eller manages a 12-story concrete building in the fashion district, where clothing buyers from Paris, Milan and Dubai trickle in each day. He said he doesn't mind spending money to keep his building in good shape and would support reasonable earthquake retrofit requirements.

After the 1985 Mexico City earthquake destroyed many concrete buildings, Eller hired a structural engineer to assess the safety of his. He said he dismissed a costly recommendation to strengthen the lower floors with thick concrete walls and took a less expensive approach. He removed unsafe brick walls, upgraded the building's sprinkler system and bought his tenants emergency kits. - LA Times.




MASS FISH DIE-OFF: Masses Of Dead Fish Continuing To Wash Up Along Neuse And Pamlico Rivers In Carolina?!

October 12, 2013 - UNITED STATES - State Water Quality officer Bert Simons estimated that fish in the Neuse River have been dying for two and a half weeks now, while Coastal Carolina River Watch’s Rick Dove says he’s been fielding calls since at least Oct. 2, when they started washing up at Carolina Pines.


Dead menhaden lie on the sidewalk at Union Point Park in New Bern Monday morning. The dead
fish began washing into the park Sunday. Chuck Beckley/Sun Journal


As of Sunday, thousands of dead menhaden were washing up along New Bern’s shores while the strong odor of their rotting carcasses could be smelled downtown. The same thing is happening along the Pamlico River, Simons said, and it’s a kill that residents can expect to see continue for at least another two weeks.

“The fish kill is just going on day after day,” Dove said. As to the size of the kill, he said, “Nobody’s out there doing a count that I know of,” but based on his experience, Dove is willing to guess that “we’re in the millions at this point. Quite possibly the tens of millions.”

Fish that are still alive “are in their death spirals,” Dove said. “You can see them everywhere.”

It is the third fish kill in four months, following on the heels of kills first reported on July 10 and Aug. 11. Dove described these kills as “moderate” in size.

The last major fish kill, in which about 200 million fish were killed, began just over a year ago on Oct. 2, 2012. That kill, Dove pointed out, took 30 days, and he expects the current one to follow a similar pattern.

Neuse Riverkeeper Lauren Wargo agreed.

“Dead fish will only float for about 48 hours, so what you see out there have just died,” she said. Wargo also described schools of fish swimming with open sores and added that the bottom of the river is littered with dead fish that have sunk. - Star News Online.


More dead fish are turning up in the east. The latest spot is along the Washington waterfront. We captured video Monday just outside the estuarium along Stewart Parkway of hundreds of dead fish.





We've also had reports of dead fish in other parts of the Pamlico River. It's believed this is part of the millions of fish killed in the Tar, Pamlico, and Neuse Rivers last week.

Thursday state officials told us they believed cooler water temperatures that promote growth of a common water mold and strong sunlight that sparks the growth of algae blooms are to blame for all the dead menhaden.
____________________________________________
PREVIOUS STORY/ October 3, 2013:
State officials believe extreme natural changes are to blame for millions of dead fish in two major river systems here in Eastern Carolina.

The dead Menhaden are turning up in both the Neuse and Tar-Pamlico river basins.

State officials believe the fish are dying due to cooler water temperatures that promote growth of a common water mold and strong sunlight that sparks the growth of algae blooms.


WATCH: More Dead Fish Discovered In Pamlico River.




The dead fish are mostly Menhaden, between three and five inches long. They've been spotted this week in the Neuse, from Union Point in New Bern to the mouth of Slocum Creek, as well in Washington, Chocowinity and Blounts Creek areas of the Tar and Pamlico rivers.

Samples of the dead fish are now being analyzed by the state. - WITN.



GLOBAL VOLCANISM: Alaska’s Veniaminof Volcano Erupts - Sends Traces Of Ash Over Two Alaskan Communities!

October 12, 2013 - ALASKA - A volcano on the Alaska Peninsula has again become active during a months-long eruption, with a trace of ash falling on communities up to 35 miles away.





The Alaska Volcano Observatory says in a release that Veniaminof Volcano resumed its 2013 eruption on Saturday after being quiet for about a month.


It's been marked by lava flows, fountaining and intermittent but small ash, steam and gas plumes.

The plumes usually only travel a few miles from the volcano, but the communities of Chignik Lake and Chignik Lagoon, about 35 miles away, reported trace ash on Friday.

The observatory says ash fall from the volcano 480 miles southwest of Anchorage is not considered to be significant. The eruption started in June. - Newsminer.




MASS MAMMAL DIE-OFF: Disaster Precursors - 18 Whales Dead After 22 Beached In Lugo, Spain?!

October 12, 2013 - SPAIN - Eighteen pilot whales from a pod of 22 copies, males, females and young-that beached on Monday Bars coruñesa beach, in the town of Manon, and had been refloated with much effort Cemma volunteers have died in the last hours, this time, on the coast of Vicedo, in Lugo.




In total, there are 18 whales dead, indicated from the Cemma, the Coordinator for the Study of Marine Mammals of Galicia-six on Monday and another eleven today, while the rest of the pack vague, disoriented today wandered upriver on the Sister has gone offshore unlikely to survive without a male guide and so close to the coast, the sources indicated.

Among the 18 pilot whales have died no males, females and young, told Efe Alfredo Lopez, spokesman for the coordinator.

Among the four remaining, three are female teenagers who were out to sea and fourth copy which is missing.

A group of 20 people, including Cemma volunteers, members of Civil Protection, Environmental technicians Xunta have worked all day today, until after 20:00 pm, looking to bail out dead specimens survivors.

The first day on the beach beached 22 Bars and died six out of the sand. They managed to survive 16, including 4 or 5 pups, which were to lead to deeper waters.

However, few hours later, more than half of the herd back to beach, this time on the other side of the estuary of O Barqueiro, Arealonga beach in Vicedo, on the coast of Lugo, and as many ( 7) being scooped by the river Sor.

Of the seven who swam the river, five have died and another disappeared.

Three returned to the ocean but no guide to lead them back to their natural habitat.

These finned specimens, a kind similar to but larger dolphin that lives in deep water near the Atlantic islands (Canaries, Madeira and Azores).

They feed on squid and fish medium. An adult male can reach five feet long and weigh nearly a ton.

The Cemma necropsies performed at some of the examples to try to locate the head of the group and find out what happened.

They suspect that he was hurt or sick, and that made him disoriented. The bodies will be cremated in order to avoid public health problems and others will serve to extract skeletons for da Natureza Museum of SGHN in Ferrol or for scientific purposes. - Ecodiario. [Translated]





GLOBAL VOLCANISM: New Zealand's White Island Volcano Erupts - Alert Level Raised, Then Lowered!

October 12, 2013 - NEW ZEALAND - The unrest at White Island continues, although GNS Science has lowered the aviation threat level from Orange to Yellow.


The dark grey apron of volcanic debris from an explosive eruption on Friday October 11, 2013 at
White Island in New Zealand, seen on October 13. Image: GNS Science.


In the past, I’ve written about the potential dangers of the tourist trips that drop off people inside the crater at White Island. Explosions can occur at a restless volcano like this unexpectedly, and with little-to-no escape route, it still strikes me as a disaster waiting to happen. Case in point, check out the video (below) of an explosion on Friday (October 11) night at White Island taken from the webcam positioned within the crater itself.


Image: GNS Science.

The video is a little dark because, well, it is nighttime, but at around 10 seconds (note: video is sped up by 5 times), you can see an explosion occur that quickly inundates the camera. The brief flashes of light are volcanic lightning, which supports the idea that the eruption was mostly older material fragmenting in a phreatic (steam-driven) explosion. Tourists get right into that crater, so if this explosion occurred during the day when tours were happening, there would have likely been severe injuries if not something worse. A picture of the crater floor (below) from Sunday (October 12) shows the new apron of debris from Friday night’s explosion.


WATCH: White Island eruption. 





Directly after the explosion, the alert level was raised to 2 and aviation threat level to Orange, but since that explosion, seismicity has settled down at the volcano, thus prompting the reduction in the aviation threat level. For those of you wondering why there are two scales, the alert level is for volcanic activity that would effect people on the ground or nearby, while the aviation threat level is for air traffic over the Bay of Plenty.

The aviation threat tends to fluctuate more as it reflects the immediate hazard of ash in the air from an explosion, while the alert status reflects the longer-term state of the volcanic system. It is interesting to note that sulfur dioxide emissions at White Island are high — close to 1000 tonnes/day — which might suggest more magma continuing to rise within the system beneath the island. However, at this point, seismicity is down so it appears that there is no immediate threat of a larger eruption. However, as GNS Science notes, explosions like the one on Friday night should be expected — we just don’t know when they might occur. - WIRED.





STORM ALERT: Category 4 Tropical Cyclone Phailin Makes Landfall In India - 500,000 Evacuated; Biggest Storm In The Region For 14 Years!

October 12, 2013 - INDIA - As many as 500,000 people in India have been evacuated as a massive cyclone sweeps through the Bay of Bengal towards the east coast.

Cyclone Phailin, categorised as "very severe" by weather forecasters, is expected to hit Orissa and Andhra Pradesh states on Saturday evening.


Locals have been shutting up businesses and taking cover as the cyclone approaches.


The Meteorological Department has predicted the storm will bring winds of up to 220km/h (136mph).

A super-cyclone in 1999 killed more than 10,000 people in Orissa.


Cyclone Phailin is expected to be the biggest storm in the region for 14 years.


But officials say this time they are better prepared, the BBC's Sanjoy Majumder in Orissa reports.

The Meteorological Department said Cyclone Phailin was due to make landfall late on Saturday evening, Indian time. The centre of the storm was expected to hit the coast around the town of Gopalpur.

Homes at risk

Officials said Cyclone Phailin would bring a storm surge of at least 3m (10ft) that was likely to cause "extensive damage" to mud houses on the coast.

"No-one will be allowed to stay in mud and thatched houses in the coastal areas,'' said Orissa's Disaster Management Minister Surya Narayan Patra.


WATCH: Very Severe Cyclone Phailin At Landfall. 





The army is on standby in the two states for emergency and relief operations. Officials said helicopters and food packages were ready to be dropped in the storm-affected areas.

Meanwhile, the US Navy's Joint Typhoon Warning Centre predicted that Phailin could produce gusts of up to 296km/h (184 mph), while the London-based Tropical Storm Risk classified Phailin as a Category Five storm - the most powerful.



As many as 500,000 people have left their homes, many for storm shelters.

Parts of Orissa and Andhra Pradesh states have suffered heavy flooding in recent days.

Fishermen have been asked not to venture out to sea.

Heavy rain and winds have already struck Orissa, where authorities have set up storm shelters for evacuees.

Janmejay Mohapatra, a resident of Orissa state capital Bhubaneswar, said it was too dangerous to go out now, as trees were down and debris was flying everywhere.




"Already the rain is very heavy and the wind is gusting at 100-120km an hour," he told the BBC. "The phone lines are down where I am and we have no electricity."

Minister Surya Narayan Patra said:"We are fighting against nature. We are better prepared this time, we learnt a lot from 1999."


WATCH: Cyclone Phailin - Windspeeds expected of 220 kms/hour, says IMD .





India's eastern coast and Bangladesh are routinely hit by cyclonic storms between April and November which cause deaths and widespread damage to property.

In December 2011, Cyclone Thane hit the southern state of Tamil Nadu, killing dozens of people. - BBC.






PLANETARY TREMORS: 6.4 Magnitude Earthquake Strikes Seafloor South Of Greece - Minor Damage To Shops And Houses, No Casualties!

October 12, 2013 - GREECE - An earthquake with a magnitude of 6.4 struck off the coast of Crete on Saturday, causing minor damage to shops and houses, but did not result in any reported casualties.


USGS earthquake location.

The earthquake reportedly took place at 4:12 p.m. (1312 GMT) and occurred at a depth of 22.5 miles, according to the U.S. Geological Survey. It could be felt throughout Greece, even in Athens, which is approximately 173 miles from the quake’s epicenter.

"The quake took place in an area known for its seismic activity,” Efthymios Lekkas, a professor of geology, told Skai radio. “It was strongly felt in Crete but also in the rest of Greece.”

According to the regional newspaper Haniotika Nea, one person in Hania, a city 42 miles east of the quake’s epicenter, sustained minor injuries during the quake after jumping from a balcony. The man, who has not been identified, reportedly panicked and flung himself from a first-floor window, landing on a car.

Despite the region’s reportedly high seismicity, a female resident of Hania told Agence Free-Presse that the duration of the quake was out of the ordinary. "It was very impressive because the shaking lasted some 40-50 seconds,” the woman, who identified herself as Vassia, said.

Local officials corroborated that report. "The earthquake was very strong and lasted long," Manoussos Lionakis, the deputy mayor of Hania, said. "Fortunately, there was no serious damage. The worst I've heard was some rock falls in a ravine west of the city. A bus was trapped, but no one was hurt. We have removed the debris.”


USGS earthquake shakemap intensity.


He added: "Right now we have employees inspecting the buildings in the old city, but, apart from some cracked marble facades here and there, we have found nothing.”

The Associated Press reported that the earthquake prompted residents to run into the streets, but local firefighters said there had not been any emergency calls or serious damage. - IBT.


Tectonic Summary - Seismotectonics of the Mediterranean Region and Vicinity.
The Mediterranean region is seismically active due to the northward convergence (4-10 mm/yr) of the African plate with respect to the Eurasian plate along a complex plate boundary. This convergence began approximately 50 Ma and was associated with the closure of the Tethys Sea. The modern day remnant of the Tethys Sea is the Mediterranean Sea. The highest rates of seismicity in the Mediterranean region are found along the Hellenic subduction zone of southern Greece, along the North Anatolian Fault Zone of western Turkey and the Calabrian subduction zone of southern Italy.



USGS plate tectonics for the region.

Local high rates of convergence at the Hellenic subduction zone (35mm/yr) are associated with back-arc spreading throughout Greece and western Turkey above the subducting Mediterranean oceanic crust. Crustal normal faulting throughout this region is a manifestation of extensional tectonics associated with the back-arc spreading. The region of the Marmara Sea is a transition zone between this extensional regime, to the west, and the strike-slip regime of the North Anatolian Fault Zone, to the east. The North Anatolian Fault accommodates much of the right-lateral horizontal motion (23-24 mm/yr) between the Anatolian micro-plate and Eurasian plate as the Anatolian micro-plate is being pushed westward to further accommodate closure of the Mediterranean basin caused by the collision of the African and Arabian plates in southeastern Turkey. Subduction of the Mediterranean Sea floor beneath the Tyrrhenian Sea at the Calabrian subduction zone causes a significant zone of seismicity around Sicily and southern Italy. Active volcanoes are located above intermediate depth earthquakes in the Cyclades of the Aegean Sea and in southern Italy.

In the Mediterranean region there is a written record, several centuries long, documenting pre-instrumental seismicity (pre-20th century). Earthquakes have historically caused widespread damage across central and southern Greece, Cyprus, Sicily, Crete, the Nile Delta, Northern Libya, the Atlas Mountains of North Africa and the Iberian Peninsula. The 1903 M8.2 Kythera earthquake and the 1926 M7.8 Rhodes earthquakes are the largest instrumentally recorded Mediterranean earthquakes, both of which are associated with subduction zone tectonics. Between 1939 and 1999 a series of devastating M7+ strike-slip earthquakes propagated westward along the North Anatolian Fault Zone, beginning with the 1939 M7.8 Erzincan earthquake on the eastern end of the North Anatolian Fault system. The 1999 M7.6 Izmit earthquake, located on the westward end of the fault, struck one of Turkey's most densely populated and industrialized urban areas killing, more than 17,000 people. Although seismicity rates are comparatively low along the northern margin of the African continent, large destructive earthquakes have been recorded and reported from Morocco in the western Mediterranean, to the Dead Sea in the eastern Mediterranean. The 1980 M7.3 El Asnam earthquake was one of Africa's largest and most destructive earthquakes within the 20th century.

Large earthquakes throughout the Mediterranean region have also been known to produce significant and damaging tsunamis. One of the more prominent historical earthquakes within the region is the Lisbon earthquake of November 1, 1755, whose magnitude has been estimated from non-instrumental data to be about 8.0. The 1755 Lisbon earthquake is thought to have occurred within or near the Azores-Gibraltar transform fault, which defines the boundary between the African and Eurasian plates off the west coast of Morocco and Portugal. The earthquake is notable for both a large death toll of approximately 60,000 people and for generating a tsunami that swept up the Portuguese coast inundating coastal villages and Lisbon. An earthquake of approximately M8.0 near Sicily in 1693 generated a large tsunami wave that destroyed numerous towns along Sicily's east coast. The M7.2 December 28, 1908 Messina earthquake is the deadliest documented European earthquake. The combination of severe ground shaking and a local tsunami caused an estimated 60,000 to 120,000 fatalities. - USGS.




GLOBAL VOLCANISM: Global Volcano Report For October 12, 2013 - Updates On Klyuchevskoy, Soufriere Hills, Jebel Zubair, Tungurahua And Etna!

October 12, 2013 - WORLDWIDE VOLCANOES - The following constitutes the new activity, unrest and ongoing reports of volcanoes across the globe, courtesy of  Volcano Discovery.


Klyuchevskoy (Kamchatka): The KVERT reported this morning that a new flank eruption between the volcanoes Kliuchevskoi and Kamen began at around 8:20 UTC. The flank eruption consisted of a strong explosion that lasted around 10 minutes and ejected an ash plume 6-7 kilometres high which then drifted east.


Lightning inside the eruption cloud above Klyuchevskoy volcano (KVERT webcam).

(11 Oct) We posted the following time-lapse video of the eruption this morning (or evening, in Kamchatka time). At 08:30 UTC (17:30 local time), a new vent opened in the saddle between Klyuchevskoy and neighboring Kamen volcano, producing a fountain of lava and ash rising to about 7 km altitude. The KVERT webcam even captured lightning during this eruption:


WATCH:  Klyuchevskoy volcano eruption with lightning.





Soufriere Hills (Montserrat, West Indies (UK)): (11 Oct) MVO reported that activity at the Soufrière Hills Volcano has remained low over the past week. The dome produced a number of rockfalls and a few volcano-tectonic earthquakes. Volcanic gas emissions were at average levels.


Jebel Zubair (Red Sea): (11 Oct) As of today, the submarine eruption continues with the production of a steam plume of variable size, not always easily identifiable on satellite images. A SO2 plume is also visible on satellite data drifting from the eruption site.


Steam plume from Zubair in the Red Sea on Tuesday (8 Oct).


No ash can be seen on satellite imagery, only steam, and the area of discolored water (indicator of suspended particles) is small if not has disappeared. That suggests that the eruption is currently rather weak and probably has not yet entered the so-called surtseyan phase where solid fragments (ash, lava blocks) are ejected above the surface of the sea.


Tungurahua (Ecuador): (10 Oct) The increase of activity continues. The Ecuadorian Instituto Geofísico (IGPEN) reported that seismic and visual activity increased since Sunday. The volcano currently produces mild to moderate strombolian activity, ejecting fresh lava bombs onto the upper slopes of the summit cone.


Strombolian activity of Tungurahua today (OVT/IGEPN).

The seismic recordings show in increase in the number of events associated with internal fluid (magma) movements as well as emission/explosion signals.

 
Etna (Sicily, Italy): (10 Oct) A swarm of shallow earthquakes occurred yesterday under the SE flank, below Monte Arcimis near Tarderia (Pedara) at depths of 2.7-5.6 km. The two largest events were magnitude 2.7 and felt by local residents.


Map of yesterday's earthquakes under Etna (marker shows one of the two mag 2.7 events).



- Volcano Discovery.