Right... I didn't think I had to emphasize it. :) You found it fine.
The point is they believe a new plate is forming and this caused some of the group of quakes we were talking about before.
And from the part you highlighted..."while analysis of 300 major earthquakes over the last 30 years had shown no large aftershocks occurring far away."
This in a way actually shows something odd is happening.
If most quakes aren't felt far off, and these few aftershocks felt very long distances off ARE then something weird happened. Thats all I was getting at.
October 28th, 2012, 08:29
Ryan Ruck
Re: Earthquakes, Plate Tectonics and Volcanism
I've been watching some movies most of the day and pretty oblivious to all ongoings in the world for a bit. Just turned on FNC before I hit the rack and see there has been a 7.7 earthquake off the western coast of Canada that has resulted in Tsunami warnings for a huge area of the western US and Alaska but Hawaii looks to be under the gun. Showing footage of traffic jammed streets as the waves are expected to impact shortly at this moment.
October 28th, 2012, 18:14
American Patriot
Re: Earthquakes, Plate Tectonics and Volcanism
Apparently some tidal waves have hit Hawaii as well
October 28th, 2012, 23:01
Ryan Ruck
Re: Earthquakes, Plate Tectonics and Volcanism
Yeah, from what I heard it wasn't much though. Something like 1.5-2ft waves but I think there may have been some 5ft waves recorded.
I will say, it was pretty funny listening to the news channels as the waves were supposedly incoming. They sounded like they were hoping there'd be waves coming ashore as big as the one in the movie Deep Impact. LOL!
Ended up being nothing more than some boats bobbing in the water.
October 29th, 2012, 00:07
American Patriot
Re: Earthquakes, Plate Tectonics and Volcanism
Mega Tusnami
hahaha
October 29th, 2012, 02:24
Phil Fiord
Re: Earthquakes, Plate Tectonics and Volcanism
October 29th, 2012, 02:27
Phil Fiord
Re: Earthquakes, Plate Tectonics and Volcanism
For the Spanish speakers:
October 29th, 2012, 04:29
Ryan Ruck
Re: Earthquakes, Plate Tectonics and Volcanism
Now there is something just not right about that Spanish version...
By the way, last I saw the area this quake happened at was still spitting out 4 and 5 magnitude aftershocks.
December 10th, 2012, 21:23
American Patriot
Re: Earthquakes, Plate Tectonics and Volcanism
hmmmmmmmmmmm so there IS a connection after all from large quakes causing other quakes....
Rare great earthquake triggers large aftershocks all over the globe
A Magnitude-8.6 earthquake on April, 11, 2012 set in motion an unprecedented increase in global seismic activity, study shows.
Large earthquakes can alter seismicity patterns across the globe in very different ways, according to two new studies by U.S. Geological Survey seismologists. Both studies shed light on more than a decade of debate on the origin and prevalence of remotely triggered earthquakes. Until now, distant but damaging “aftershocks” have not been included in hazard assessments, yet in each study, changes in seismicity were predictable enough to be included in future evaluations of earthquake hazards. http://en.es-static.us/upl/2012/09/A...quake_580.jpegRemote earthquakes in the six days preceding (top) and the six days following (bottom) the M=8.6 main shock in the East Indian Ocean on April 11, 2012. The color scale indicates seismic stress, with purple = zero and red = high.
In a study published in this week’s issue of “Nature,” USGS seismologist Fred Pollitz and colleagues analyzed the unprecedented increase in global seismic activity triggered by the Magnitude-8.6 East Indian Ocean quake of April 11, 2012, and in a recently published study in the “Proceedings of the National Academy of Sciences,” seismologist Volkan Sevilgen and his USGS colleagues investigated the near-cessation of seismic activity up to 250 miles away caused by the 2004 M9.2 Sumatra earthquake.
While aftershocks have traditionally been defined as those smaller earthquakes that happen after and nearby the main fault rupture, scientists now recognize that this definition is wrong. Instead, aftershocks are simply earthquakes of any size and location that would not have taken place had the main shock not struck.
“Earthquakes are immense forces of nature, involving complex rock physics and failure mechanisms occurring over time and space scales that cannot be recreated in a laboratory environment,” said USGS Director Marcia McNutt. “A large, unusual event such as the East Indian earthquake last April is a once-in-a-century opportunity to uncover first order responses of the planet to sudden changes in state of stress that bring us a little closer to understanding the mystery of earthquake generation.”
Global aftershock study: April 2012: East Indian Ocean quake triggers many distant quakes
An extraordinary number of earthquakes of M4.5 and greater were triggered worldwide in the six days after the M8.6 East Indian Ocean earthquake in April 2012. These large and potentially damaging quakes, occurring as far away as Mexico and Japan, were triggered within days of the passage of seismic waves from the main shock that generated stresses in Earth’s crust.
The East Indian Ocean event was the largest — by a factor of 10 — strike-slip earthquake ever recorded (the San Andreas is perhaps the most famous strike-slip fault). “Most great earthquakes occur along subduction zones and involve large vertical motions. No other recorded earthquake triggered as many large earthquakes elsewhere around the world as this one,” said Pollitz, “probably because strike-slip faults around the globe were more responsive to the seismic waves produced by a giant strike-slip temblor.”
Another clue in the six days of global aftershocks following the M8.6 quake is that the rate of global quakes during the preceding 6-12 days was extremely low. “Imagine an apple tree, with apples typically ripening and then falling at some steady rate,” Stein said. “If a week goes by without any falling, there will be more very ripe apples on the tree. Now shake the trunk, and many more than normal might drop.”
http://en.es-static.us/upl/2012/09/2...hquake_350.pngSome 380 seconds into the greatest earthquake to rupture since 1960, the simulated dynamic Coulomb stress waves (red-blue) shed continuously off the 2004 M=9.2 Sumatra rupture front can be seen sweeping through the Andaman Sea, where faults remarkably shut down for the next five years.
Earthquakes since 1964 are shown as black dots, and the Sunda trench along which the 1400-km-long earthquake occurred is the arcuate black line on the left (west). Sumatra is on the right, and Myanmar/Burma is at top. Sevilgen et al (Proc. Nat. Acad. Sci, 2012) find that despite the magnitude of thesedynamic stress waves, the much smaller permanent stresses account for the change in seismicity after the main shock. Image Credit: Seismicity.net.
The authors emphasize that the week of global triggering seen after the East Indian Ocean quake has no bearing on the hypothesis advanced by others that the 2004 M9.2 Sumatra, 2010 M8.8 Maule, Chile, and 2011 M9.0 Tohoku, Japan, are related to each other. Instead, the effect of increased earthquakes lasted a week—not a decade.
Sumatra quake affects faults up to 250 miles away
While global triggering of large aftershocks appears very rare, regional triggering is common and important to understand for post-main shock emergency response and recovery. Sevilgen and his USGS colleagues studied the largest quake to strike in 40 years to understand just how great the reach is on aftershock occurrence. After the M9.2 earthquake in Sumatra in 2004, aftershocks larger than M4.5 ceased for five years along part of a distant series of linked faults known as the Andaman back arc fault system. Along a larger segment of the same system, the sideways-slipping transform earthquakes decreased by two-thirds, while the rate of rift events – earthquakes that happen on a spreading center – increased by 800 percent, according to Sevilgen and his colleagues at the USGS. These very large, but distant seismicity rate changes are unprecedented.
The authors investigated two possible causes for the changes in remote seismicity rates: the dynamic stresses imparted by the main shock rupture, which best explain the global triggering in the April 2012 quake case; and the small but permanent stress changes, which best explain this one. The authors found that the main shock brought the transform fault segments about ¼ bar of pressure farther from static failure, and the rift segments about ¼ bar closer to static failure (for comparison, car tires are inflated with about 3 bars of pressure), which matches the seismic observations.
Why it matters
Incorporating the probability of aftershocks into the hazard assessment of an area is important because the damage of even a moderate aftershock sometimes exceeds that wrought by the main event. For example, a M6.3 aftershock five months after the M7.1 New Zealand earthquake in 2010 hit a more populated area, causing 181 deaths and tripling the insured property damage of the main event.
That is afterquakes. You were discussing precursor quakes as indicators of upcoming mega quakes. That's the cart after the horse so to speak and not surprising at all.
December 11th, 2012, 00:03
American Patriot
Re: Earthquakes, Plate Tectonics and Volcanism
Quote:
Originally Posted by Malsua
That is afterquakes. You were discussing precursor quakes as indicators of upcoming mega quakes. That's the cart after the horse so to speak and not surprising at all.
Ummm.. I think you got this wrong Mal.
A "precursor quake" (and that's a word you made up, not me lol) is nothing more than a QUAKE that happens then there are "aftershocks".
The way I see it, these big quakes are followed by OTHER big quakes somewhere else.
In fact, Japan has a big assed fucking quake a couple of weeks back, now Thailand gets one (or whoever the hell it was, I can't tell one oriental place from another, and most of them are full of commies or Muslims, so who cares anyway?)
The point I was attempting to make before was that these big quakes are connected to OTHER big quakes a few days or weeks later (not decades, weeks).
February 14th, 2013, 13:53
American Patriot
Re: Earthquakes, Plate Tectonics and Volcanism
Hmmm Eastern Siberia... Russia.... Nuke test?
6.9 - EASTERN SIBERIA, RUSSIA
Preliminary Earthquake Report
Magnitude
6.9
Date-Time
14 Feb 2013 13:13:53 UTC
15 Feb 2013 00:13:53 near epicenter
14 Feb 2013 06:13:53 standard time in your timezone
Location
67.613N 142.601E
Depth
9 km
Distances
340 km (211 miles) N (356 degrees) of Ust'-Nera, Russia
389 km (242 miles) E (85 degrees) of Verkhoyansk, Russia
866 km (538 miles) NE (39 degrees) of Yakutsk, Russia
2970 km (1845 miles) NNE (30 degrees) of ULAANBAATAR, Mongolia
Location Uncertainty
Horizontal: 14.7 km; Vertical 2.8 km
Parameters
Nph = 608; Dmin = 983.4 km; Rmss = 1.18 seconds; Gp = 27°
Version = 8
Mount Mayon has erupted dozens of times since records began
A volcano has erupted in the Philippines, killing four German climbers and their guide.
Mount Mayon, 330km (206 miles) south-east of the capital Manila, sent a cloud of ash and rocks into the sky early on Tuesday.
The ash blast caught a group climbing the mountain, which is famous for its near-perfect cone.
At least seven other climbers were hurt in the eruption, which lasted for just over a minute.
"Five killed and seven are injured, that is the latest report," National Disaster Risk Reduction and Management Council chief Eduardo del Rosario said.
Four of those killed were German nationals and the fifth was their Filipino guide, the NDRRMC said later in a statement.
A guide on the mountain told a local television station by telephone that those who died were hit by the rocks that rained down on them after the ash blast.
Twenty people were approaching the summit of the mountain when the eruption occurred.
"It was so sudden that many of us panicked," Jun Marana, a local resident, told AFP news agency. "When we stepped out we saw this huge column against the blue sky."
In an advisory, the Philippine Institute of Volcanology and Seismology called the eruption a "small phreatic event" that lasted about 73 seconds and sent ash 500m into the air. No intensification of volcanic activity was observed, it said, and the alert level would not be raised.
But it said small steam and ash ejections could occur with little or no warning and advised against entry to the 6-km (4-mile) radius Permanent Danger Zone around the volcano.
Chief state seismologist Renato Solidum described the eruption as a "stream driven explosion", a "normal process" in any volcano. There was no need for local residents around the mountain to evacuate, he said.
Mt Mayon has erupted at least 48 times since records began. The most violent eruption, in 1814, killed more than 1,200 people and devastated several towns.
The most recent eruption was in late 2009, when tens of thousands of local residents were forced to evacuate as the volcano rumbled back to life.
Ash and water vapor soar above Mexico's Popocatepetl crater
Ash falls on several towns and parts of the city of Puebla
Authorities prevent people from going within a 7-mile radius of the volcano
On a clear day, Popocatepetl can be seen in Mexico City
(CNN) -- Mexico's Popocatepetl volcano rumbled Saturday with explosions and expulsions of ash and gas, prompting authorities to bar people from getting close to a crater that is within sight of Mexico City and many of its 19 million residents.
The country's National Center for Disaster Prevention reported that -- following 12 "low-intensity" emissions of a small amount of water vapor and gas -- there was "an exhalation with some explosive component" around 9 a.m. (10 a.m. ET).
This was "followed by a spasmodic tremor ... with moderate to large amplitudes, which has been accompanied by a continuous emission of ... ash and water vapor," according to the government agency.
At that time, the emissions had gone at most 400 meters (1,300 feet) above Popocatepetl's crater. Ash had fallen on the towns of San Nicolas de los Ranchos and Huejotzingo, as well as the northern part of the city of Puebla.
As the day wore on, the volcanic material soared even higher. An updated government report at 2 p.m. -- three hours after the first one went out -- indicated that ash, steam and gas were spewing an average of 500 meters up into the sky.
Mexican authorities restricted access within 12 kilometers (7.5 miles) of the volcano.
Located in a national park southeast of Mexico City, Popocatepetl can be seen from there on a clear day. It is one of Mexico's highest peaks and last had a major eruption in 2000.
http://www.bigislandvideonews.com/wp...05/25_-175.jpgHONOLULU, Hawaii – A magnitude 7.4 earthquake has struck south of the Fiji Islands, but no Pacific wide tsunami is expected and there is no tsunami threat to Hawaii.
The Pacific Tsunami Warning Center says based on all available data a destructive tsunami has not been generated.
The quake happened 106 miles below the ocean, and was actually closest to Vaini, Tonga (174 miles to southwest.)
The quake was 441 miles southeast of Suva, Fiji.
According to the United States Geological Survey, the Eastern Margin of the Australia Plate, which stretches from New Zealand to the east of Tonga and Fiji, is highly active.
From the USGS Tectonic Summary:
The eastern margin of the Australia plate is one of the most sesimically active areas of the world due to high rates of convergence between the Australia and Pacific plates. In the region of New Zealand, the 3000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand.
Since 1900 there have been 15 M7.5+ earthquakes recorded near New Zealand. Nine of these, and the four largest, occurred along or near the Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting intraplate deformation. The largest recorded earthquake in New Zealand itself was the 1931 M7.8 Hawke’s Bay earthquake, which killed 256 people. The last M7.5+ earthquake along the Alpine Fault was 170 years ago; studies of the faults’ strain accumulation suggest that similar events are likely to occur again.
North of New Zealand, the Australia-Pacific boundary stretches east of Tonga and Fiji to 250 km south of Samoa. For 2,200 km the trench is approximately linear, and includes two segments where old (>120 Myr) Pacific oceanic lithosphere rapidly subducts westward (Kermadec and Tonga). At the northern end of the Tonga trench, the boundary curves sharply westward and changes along a 700 km-long segment from trench-normal subduction, to oblique subduction, to a left lateral transform-like structure.
These ominous pictures show volcanic smoke billowing from one of Japan's most active volcanoes, Mount Sakurajima, captured as its erupted for the 500th time this year.
At 5000m, this is the highest plume of ash recorded from the mountain since 1955, and caused darkness and ash falls over the centre of nearby Kagoshima city.
Situated on the southern Japanese main island of Kyushu, the 1,117 metre (3,686 ft) volcano began erupting on the night of August 18, local time.
The images, taken by the Kagoshima Local Meteorological Observatory, show ash pouring from the volcano's summit.
Locals living in the shadow of Sakurajima have been urged to cover up and wear masks as a health and safety measure, but there are no immediate reports of injuries.
Volcanologists believe the mountain may spew out more ash this year than in the previous two decades.
Masato Iguchi, a professor at the Sakurajima Volcano Research Center, said 2012 saw a record number of eruptions.
Kyoto University’s disaster reduction research institute keeps close tabs on the volcano in order to avoid a repeat of its 1914 eruption, in which 58 people died.
That episode was the most powerful volcanic eruption to hit Japan in a hundred years.
At present, Sakurajima erupts on a small scale several thousand times a year, sending ash a few kilometres above its peak.
Motorists on Saturday were alarmed to notice hot, stinking gas spurting from a newly formed crater in the middle of a roundabout close to the perimeter fence of Rome’s Fiumicino airport -- less than 900 yards from the end of a runway.
Spectators gathered around the smoking crater, which measured about six feet wide and three feet deep, before firefighters and vulcanologists arrived to seal off the roundabout to prevent inhalation of the gas, suspected to be a cocktail of carbon dioxide, hydrogen sulphide and methane. Tests are now underway.
While initial reports suggested the gas came from rotting organic matter trapped underground, one expert said volcanic activity was more likely.
“From Mount Etna in Sicily up to the Alban hills around Rome there is a good deal of underground volcanic activity,” Alberto Basili, a seismologist at the Italian National Institute for Geophysics and Vulcanology, told the Daily Telegraph.
The area covers Mount Vesuvius, which buried the Roman city of Pompeii when it erupted in 79AD, to a number of lakes formed in extinct volcanoes north of Rome.
“Gas underground can remain hot for tens of thousands of years after volcanoes erupt, and every now and then it can rise to the surface from miles underground,” said Mr Basili.
“We have seen things like this elsewhere around Rome, with farm animals being killed after they breath in the gas,” he said.
Despite being a stone’s throw from the end of a main runway at Fiumicino, Europe’s sixth largest airport, which handles 37 million passengers a year, Mr Basili said there was no cause for fear over flight safety. “This is a limited phenomenon – it will not have created alarm at the airport,” he said.