Aardbevingen #10

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Op vrijdag 18 februari 2011 10:14 schreef Frutsel het volgende:
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Weer Arkansas... 4.0 en 4.3

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"to always have an all-hazards disaster preparedness kit."

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Turkey quake may give warning clues - 1 hour before actual quake strikes
A series of foreshocks which preceded the 1999 Turkey earthquake may provide clues to increased warning times, say an international team of geoscientists.

It is known that some earthquakes are preceded by foreshocks, but so far scientists have been unable to distinguish foreshocks from the almost constant minor seismic activity at plate boundaries. Until foreshocks are followed by a major quake, there is no way of objectively determining that that's what they actually were.

In research published today in Science lead author, Dr Michel Bouchon of the National Centre for Scientific Research at The Université Joseph Fourier in Grenoble, and his co-authors in Turkey, looked at seismic records from recording stations near the epicentre of the magnitude 7.6 earthquake, which devastated the city of Izmit in northwestern Turkey.

Bouchon says they chose the Izmit earthquake because it was one of the best recorded large earthquakes to date.

"It also occurred on the fault which has been the most seismically active continental fault in the past 100 years, with nine earthquakes of magnitude 7 or greater."

Previous research has shown the earthquake was caused by two tectonic plates sliding along a 150-kilometre section of the fault-line in the brittle upper-crust, which in this region is about 17 kilometres thick. Below the upper-crust, rocks are hotter and more ductile and the two plates move past each other continuously at a rate of about 2.5 centimetres a year. The upper-crust usually remains still, but occasionally it catches up with the movement below, resulting in a jolting earthquake.

Whole lot o' shakin' goin' on

In this study, Bouchon and colleagues have identified a pattern of continuous background vibration in the 44 minutes before the earthquake struck.

During that time there was a long-duration seismic signal consisting of a succession of repetitive seismic bursts.

Bouchon says that the seismic vibration before the quake was caused by slow, irregular slipping of the fault at depth, in the zone where the earthquake began - the hypocentre.

The hypocentre for the Izmit quake is estimated to have been 13 to 17 kilometres below the surface. That puts the zone of nucleation close to the base of the brittle part of the crust.

"The fault is slipping slowly in that area, and a patch of the fault - which has a size of a few hundred metres - is resisting this slipping," he says. "The irregular slip produces the foreshocks."

According to Bouchon and co-authors, laboratory and theoretical models of earthquake nucleation predict that there should be slip instability before earthquakes, but whether that instability is large enough to be detected, and lasts for long enough to be useful, is not known.

The authors say the next step is to re-examine the near-fault seismic records of other large, well-recorded earthquakes and see if there are similar signals.
From tens of seconds to tens of minutes

Professor Phil Cummins, a seismologist at the Australian National University in Canberra, says our knowledge of what is really going on that deep in the crust is limited. But he says the study by Bouchon and colleagues is just one small step to better understanding what happens immediately before a quake.

"[This research] seems very exciting," Cummins says.

"This is the most solid evidence I've seen that there is a phase of accelerated creep prior to an earthquake that potentially could be observable a reasonable time beforehand," he says.

"[Current] earthquake early warning is aimed at giving seconds or tens of seconds warning", he says, "and in that time it's possible to take measures that might reduce fatalities, things like shut down gas mains, stop trains, shut down critical systems. So if you have tens of minutes I would say that's significant."

"I'm sure that many seismologists are going to go back and look at their records ... I'd be disappointed and a little surprised if no one else found this."

"But a lot of work still needs to be done before it can be used as an operational early warning system," he says.

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Op vrijdag 18 februari 2011 16:33 schreef Roel_Jewel het volgende:
Vandaag is het precies 255 jaar geleden dat de zware aardbeving bij Düren plaatsvond. http://goo.gl/BkcNV Dat u het weet.

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Op dinsdag 22 februari 2011 01:40 schreef Roel_Jewel het volgende:
Aardbeving (6.3) treft Christchurch, NieuwZeeland

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Op dinsdag 22 februari 2011 02:13 schreef rechtsedirecte het volgende:
http://www.nzherald.co.nz(...)ry_id=116912#7379145

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Gletsjer breekt af door aardbeving Nieuw-Zeeland
Uitgegeven: 22 februari 2011 12:19
Laatst gewijzigd: 22 februari 2011 12:19

AMSTERDAM - Als gevolg van de aardbeving in Christchurch dinsdag is dertig miljoen ton ijs afgebroken van de grootste gletsjer in Nieuw-Zeeland.
Schade na aardbeving Nieuw-Zeeland.

Gidsen bij de Tasmangletsjer in de Zuidelijke Alpen hebben gezegd dat door de aardbeving stukken ijs van de gletsjer zijn afgebroken, die vervolgens ijsbergen vormden in het meer waar het smeltwater van de gletsjer in uitmondt.

Volgens toeristen op de rondvaartboten bij de gletsjer veroorzaakten de ijsblokken golven tot wel 3,5 meter hoog.

De gletsjer ligt op zo'n 200 kilometer van Christchurch. In de stad zijn zeker 65 doden gevallen. Er wordt vermoed dat nog meer dan honderd mensen onder het puin van ingestorte gebouwen liggen.

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Op dinsdag 22 februari 2011 13:50 schreef zenkelly het volgende:

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www.nu.nl

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Op woensdag 23 februari 2011 12:13 schreef Frutsel het volgende:
Foto genomen net buiten Christchurch, luttele ogenblikken na de aardbeving

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Op woensdag 23 februari 2011 12:13 schreef Frutsel het volgende:
Foto genomen net buiten Christchurch, luttele ogenblikken na de aardbeving

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Lyttelton volcano will not come back to life
Fears that Lyttelton's extinct volcano could come back to life following last week's devasting earthquake in Christchurch are unfounded, experts say.

Over the past week there has been plenty of discussion amongst some groups that the Lyttelton Volcano - an incredibly old and extinct volcano - was perhaps coming back to life following last week's horrific earthquake.

WeatherWatch.co.nz asked GeoNet experts if the volcano could come back to life, and was in any way connected to the recent severe earthquake activity.

GeoNet's Sara Page said: "There has been a lot of talk on the Lyttelton Volcano. Rest assured none of the current activity in Christchurch is of volcanic origin, and is not going to re-awaken the long extinct volcano.

"Luckily for all of those in the South Island, all of the volcanic activity is in the North Island".

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Chili opnieuw getroffen door aardbeving

Chili is vandaag getroffen door een aardbeving met een kracht van 6,2 op de schaal van Richter. Het epicentrum van de beving ligt ongeveer 100 kilometer ten noordoosten van Arica op een diepte van 110 kilometer.

Geen schade bij kopergiganten
In eerste instantie werd gemeld dat de kracht van de beving nog een tiende groter was dan de 6,2 waarop hij nu wordt gemeld. “Er zijn geen meldingen van gewonden of schade aan de infrastructuur”, zei een woordvoerder van de noodhulp in de regio. De bevolking zou alleen opgeschrikt zijn.

Het staatsbedrijf Codelco,’s werelds grootste koperproducent, meldde nog geen schade aan installaties. De op twee na grootste kopermijn Collahuasi werd ook niet getroffen en zegt haar productie op het standaardniveau te kunnen uitvoeren.

Vorig jaar bijna vijfhonderd doden
Vorig jaar rond deze tijd werd Chili opgeschrikt door een serie zware aardbevingen. Na een beving eind februari 2010 met een kracht van van 8,8 werd destijds geen tsunamiwaarschuwing gegeven. Bewoners aan de kust werden toen verrast door vloedgolven waardoor in totaal 497 doden vielen. In maart volgden nog een aantal bevingen met een kracht van 7,2.

Arica ligt in een regio bij de grens met Peru en Bolivia. De zware beving van februari 2010 vond plaats ten noorden van Concepción. Dat is de op twee na grootste stad van Chili en ligt ruim 2.500 kilometer onder Arica.

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Tsunami-alarm na zware aardbeving in Japan

TOKIO - Het noordoosten van Japan is getroffen door een krachtige aardbeving. Gebouwen schudden heen en weer en enkele hogesnelheidstreinen vielen automatisch even stil.
De politie had tot dusver geen meldingen van grote schade binnengekregen, maar de beving kon naar verluidt gevoeld worden tot in Tokio.

De beving had een kracht van 7,2 op de schaal van Richter. Het epicentrum lag 160 kilometer ten oosten van het noordelijke eiland Honshu, 10 kilometer onder het zeeoppervlak. Na de beving is een tsunami-alarm uitgevaardigd. De diensten verwachten een golf van 50 centimeter.

De beving duurde ongeveer 20 seconden, zeiden getuigen. Het deed zich voor rond 12 uur 's middags lokale tijd. Japan behoort tot de landen met de meeste aardbevingen ter wereld.

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MAP 5.1 2011/03/09 06:25:12 38.299 143.067 10.8 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 4.9 2011/03/09 06:12:13 38.681 143.022 10.0 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 4.7 2011/03/09 05:27:06 37.830 145.135 10.0 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 5.3 2011/03/09 04:45:54 38.543 142.740 27.0 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.7 2011/03/09 04:37:03 38.666 142.991 25.5 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.2 2011/03/09 04:32:10 38.727 143.001 32.1 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 4.8 2011/03/09 04:15:39 38.857 142.658 12.6 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.2 2011/03/09 04:05:53 38.870 142.420 10.9 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.0 2011/03/09 03:19:00 38.795 142.962 19.9 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.2 2011/03/09 03:08:35 38.339 143.097 24.4 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 5.6 2011/03/09 02:57:16 38.402 142.825 17.5 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 7.2 2011/03/09 02:45:18 38.510 142.792 14.1 NEAR THE EAST COAST OF HONSHU, JAPAN

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Op woensdag 9 maart 2011 08:29 schreef Frutsel het volgende:
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MAP 5.3 2011/03/09 08:02:36 38.606 143.103 15.4 OFF THE EAST COAST OF HONSHU, JAPAN
MAP 5.1 2011/03/09 07:56:27 38.849 142.929 10.7 NEAR THE EAST COAST OF HONSHU, JAPAN
MAP 5.0 2011/03/09 07:13:48 38.246 143.108 9.9 OFF THE EAST COAST OF HONSHU, JAPAN

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Beijing (CNN) -- The death toll from Thursday's earthquake in southwest China is at least 14, with more than 120 injured, the civil affairs ministry told CNN.

The 5.4-magnitude earthquake hit near the Myanmar border, the U.S. Geological Survey said.

Earlier, Chinese state television had put the number of wounded at 211.

The quake collapsed houses in the remote Yingjiang county in Yunnan province, the ministry of civil affairs said.

State media said the quake hit the area shortly before 1 p.m. local time, cutting down power and toppling buildings that included hotels and schools.

The epicenter was two kilometers away from the center of Yingjiang county, which has a population of more than 270,000 and is home to several of China's ethnic minorities.

China Central Television showed damaged buildings with debris and red lanterns lying around as police officers directed traffic on a chaotic street.

Aftershocks continued to jolt the area as firefighters and other rescuers helped the people trapped, Li Zhiren, the deputy county chief told CCTV.

Minor quakes under magnitude 5 began shaking the area this year, according to Xinhua news agency.

The local seismological bureau had recorded more than 1,200 such tremors before Thursday, Xinhua said.

Many jittery residents celebrated the lunar New Year holiday in tents last month.

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Geen schade na krachtige aardbeving in Papoea-Nieuw-Guinea

Papoea-Nieuw-Guinea is vandaag getroffen door een aardbeving met een kracht van 6,6 op de schaal van Richter. De beving heeft geen schade veroorzaakt, zo melden seismologen.

Het epicentrum bevond zich op een dertigtal kilometer ten noordoosten van de kleine stad Kandrian,
op het eiland Nieuw-Brittannië. (afp/adb)

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Op donderdag 10 maart 2011 11:02 schreef SoldMayor het volgende:

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Death toll after quake in SW China rises to 22 with 201 injured, BNO News confirms

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Op donderdag 10 maart 2011 13:23 schreef zenkelly het volgende:
Erg vreemd trouwens, dat een 5.4 met een diepte van 38 km. doden en gewonden geeft, terwijl die van Japan een 7.2 was en dat daar geen berichten zijn over gewonden, doden of schade....

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Op vrijdag 11 maart 2011 07:38 schreef Tourniquet het volgende:
Wow, 8.8 voor de Japanse kust!

http://earthquake.usgs.go(...)uakes/usc0001xgp.php

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Op vrijdag 11 maart 2011 08:19 schreef Keiichi het volgende:
http://www.knmi.nl/~sleeman/LIVE_new/intro.html

Slaan de seimosgraven hier nou uit van die aarbeving in Japan, of beven we zelf ook een beetje?

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HONOLULU The Pacific Tsunami Warning Center in Hawaii has widened its tsunami warning to include Hawaii and the rest of the Pacific Ocean, while a watch notice was issued for west coast of the U.S.

Sirens were sounded in Honolulu shortly after the warning was issued Thursday at 9:31 p.m. Haiwaii time.

The warning follows a massive earthquake that has struck off the northeastern coast of Japan.

It says the estimated earliest arrival in Hawaii of the first tsunami wave is 2:59 a.m. local time time Friday (7:59 a.m. ET).

"A tsunami has been generated that could cause damage along the coastlines of all islands in the state of Hawaii," the Pacific Tsunami Warning Center's bulletin said. "Urgent action should be taken to protect lives and property."

A tsunami watch was also issued for the coasts of Oregon, Washington and California as well as parts of Alaska, The Oregonian newspaper reported. The paper said any wave which reached the coast could hit just before 7:30 a.m. local time Friday.

The warning also includes Australia, New Zealand, Mexico and Central and South America. The coast of North America is not included in the warning.

Tsunami warnings are issued due to the imminent threat of a tsunami.