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Topic started on 2-10-2009 @ 12:34 PM by schrodingers dog
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Folks it looks like there is much more to come in the form of severe earthquakes in Sumatra:
The earthquake which devastated the city of Padang in Sumatra, Indonesia, this week, killing more than 1100 people, may have been only a hint
of worse to come. Since 2004, geologists have been predicting a far nastier earthquake in the region – a shallow tremor that will rip the sea floor
apart, trigger a devastating tsunami and kill far more people.
"Another earthquake is on its way, and all it will take to trigger it is the pressure of a handshake," says John McCloskey, a seismologist at the
Environmental Sciences Research Institute at the University of Ulster in Coleraine, Northern Ireland.
Padang experienced a magnitude-7.6 earthquake on 30 September, just after 5 pm local time. Images of terrified relatives waiting to identify dead
bodies, their T-shirts clutched over their noses to mask the stench, military officials stalking between bright yellow, zipped-up body bags and
centuries-old Dutch colonial mansions obliterated in an instant have flooded around the world.
At first, geologists assumed this was the earthquake they had predicting for many years. "Padang has bad geology," explains McCloskey. "It sits 40
kilometres above the most earthquake-prone stretch of the interface between the Indo-Australian and Eurasian plates."
This interface has not experienced the stress relief of an earthquake for over 200 years, according to McCloskey's analysis of historical coral
growth rings, which show no sign of seafloor uplift. GPS measurements of the rate of plate motion suggest that there has been around 13 metres of
movement in this area over the same period. "A shallow earthquake at the plate interface off Padang is long, long overdue," says
McCloskey.www.newscientist.com... (emphasis mine)
The study and potential tsunami consequences:
Several independent indicators imply a high probability of a great (M > 8) earthquake rupture of the subduction megathrust under the Mentawai
Islands of West Sumatra. The human consequences of such an event depend crucially on its tsunamigenic potential, which in turn depends on
unpredictable details of slip distribution on the megathrust and how resulting seafloor movements and the propagating tsunami waves interact with
bathymetry. Here we address the forward problem by modelling about 1000 possible complex earthquake ruptures and calculating the seafloor
displacements and tsunami wave height distributions that would result from the most likely 100 or so, as judged by reference to paleogeodetic data.
Additionally we carry out a systematic study of the importance of the location of maximum slip with respect to the morphology of the fore-arc complex.
Our results indicate a generally smaller regional tsunami hazard than was realised in Aceh during the December 2004 event, though more than 20% of
simulations result in tsunami wave heights of more than 5 m for the southern Sumatran cities of Padang and Bengkulu. The extreme events in these
simulations produce results which are consistent with recent deterministic studies. The study confirms the sensitivity of predicted wave heights to
the distribution of slip even for events with similar moment and reproduces Plafker's rule of thumb. Additionally we show that the maximum wave
height observed at a single location scales with the magnitude though data for all magnitudes exhibit extreme variability. Finally, we show that for
any coastal location in the near field of the earthquake, despite the complexity of the earthquake rupture simulations and the large range of
magnitudes modelled, the timing of inundation is constant to first order and the maximum height of the modelled waves is directly proportional to the
vertical coseismic displacement experienced at that point. These results may assist in developing tsunami preparedness strategies around the Indian
Ocean and in particular along the coasts of western Sumatra. sciencedirect
The numbers and prediction:
The great Sumatra–Andaman earthquake and tsunami of 2004 was a dramatic reminder of the importance of understanding the seismic and tsunami
hazards of subduction zones1, 2, 3, 4. In March 2005, the Sunda megathrust ruptured again, producing an event5 of moment magnitude (Mw) 8.6 south of
the 2004 rupture area, which was the site of a similar event in 1861 (ref. 6). Concern was then focused on the Mentawai area, where large earthquakes
had occurred in 1797 (Mw = 8.8) and 1833 (Mw = 9.0)6, 7. Two earthquakes, one of Mw = 8.4 and, twelve hours later, one of Mw = 7.9, indeed occurred
there on 12 September 2007. Here we show that these earthquakes ruptured only a fraction of the area ruptured in 1833 and consist of distinct
asperities within a patch of the megathrust that had remained locked in the interseismic period.
This indicates that the same portion of a megathrust can rupture in different patterns depending on whether asperities break as isolated seismic
events or cooperate to produce a larger rupture. This variability probably arises from the influence of non-permanent barriers, zones with locally
lower pre-stress due to the past earthquakes. The stress state of the portion of the Sunda megathrust that had ruptured in 1833 and 1797 was probably
not adequate for the development of a single large rupture in 2007. The moment released in 2007 amounts to only a fraction both of that released in
1833 and of the deficit of moment that had accumulated as a result of interseismic strain since 1833. The potential for a large megathrust event in
the Mentawai area thus remains large. www.nature.com... (emphasis mine)
Now I understand that earthquake predictions are a difficult thing to get right. After all we've been warned about "the big one" coming to
California for a long time. (knocking on wood)
But from my limited understanding of the science it seems that what they are saying here, is that the plates have been stressed beyond what they can
handle and that a major earthquake to relieve that stress is imminent. Also that recent quakes have not fully released that stress.
I'm not sure what that means in time frames ... it could be a year, ten years, or even tomorrow. But from what I'm understanding we're not talking
a century away.
Perhaps someone who is more versed in the science than myself could share their input. 
Related article: Megathrust earthquake could
hit Asia 'at any time'
[edit on 2 Oct 2009 by schrodingers dog]
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reply posted on 2-10-2009 @ 01:02 PM by Charismagic
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reply to post by schrodingers dog
Holy Moly! 
If accurate, this is bad news, not only for Indonesia, but also for the entire belt. A tsunami triggered by an earthquake can affect all the
surrounding areas, parts of the Indian Ocean, reaching Bangladesh, Sri Lanka, India....
If I understand the article correctly, the recent earth fart did not release the stress on the plates enough, so more farts and more devastation on
the way....
Fingers crossed...
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reply posted on 2-10-2009 @ 01:21 PM by ChemBreather
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Hmm, I wonder when they are going to say it could be external forces doing this, like increased pressure from space or something like that !!!
The Squize effect that Cliff High from WebBotProject speaks about ....
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reply posted on 2-10-2009 @ 01:26 PM by Grayelf2009
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If we are truley lining up with the Milky Way,plus it just happens to be the same time for a peak solar cycle ( huge magnetic waves ) ,plus, the
melting ice/water weight displacment. I would venture we are gonna see serious movement.
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reply posted on 2-10-2009 @ 01:34 PM by pyrytyes
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reply to post by schrodingers dog
Thank you for the research effort...
It is hard to argue with the data provided, not that I would, but not having first hand access I (we) have to accept it as given.
Predicting earthquakes is a guessing game: Collect the data, as best one can from previous events; determine the frequency of past quakes, if
possible; generate a model based on the frequencies and displacements, and estimated historical magnitudes, based on observations...Then make your
best guess.
From the model, an estimate of the magnitude can be approximated.
However, the information can not tell one if the future 'quake will be "the one", or if there will be smaller events occurring with increased
frequency.
The data suggests that another event is in the making to relieve the plate boundary stresses. I, along with many others, wish that I could say with
confidence "WHEN". Geology, seismology, is not yet at that stage of development.
However, the indications are, according to Jim Burkhart, a window of Oct. 17 thru the 24th, exists that makes the next major event quite
possible.
Jim is the man who predicted the "Word Series" quake in San Francisco (Oct. 17, 1989) three days before it happened. He lost his job with the USGS
because of his prediction, says he. His site is syzygyjob.com, and his predictions can be seen there along with reasons behind the predictions.
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reply posted on 2-10-2009 @ 02:20 PM by schrodingers dog
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reply posted on 2-10-2009 @ 08:53 PM by OzWeatherman
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Actually I would only speculate that this is possible.
The more earthquakes you get, the more pressure is released gradually. I would be more frightened if there was a alck of earth quakes in this region.
Im not a seismiologist but I have worked in northern australia where we often feel the earthquakes in this region...and they are always a frequent
event.
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reply posted on 2-10-2009 @ 08:59 PM by JacKatMtn
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Anyone heard of Anak Krakatoa?
Isn't this in the same geographic area?
If so, could these recent quakes create another worry, ie volcanic activity..
If I remember correctly, Anak Krakatoa means son of Krakatoa..
Hopefully my memory is failing me 
Don't want to alarm, just want to create awareness..
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reply posted on 2-10-2009 @ 09:04 PM by OzWeatherman
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reply to post by JacKatMtn
Yep its in the same region
When I worked in Darwin met office before I moved here...we used to have a volcanic ash desk, who's main job it was to inform aviators of volcanic
ash plumes. Krakatoa was one of the volcanos that seemed to constantly be spewing out ash, but many volcanos on the ring of fire do
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reply posted on 2-10-2009 @ 09:07 PM by dallas18
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reply to post by JacKatMtn
yeah! and you are correct with anak 
here is where it is located
i have had a feeling for some time that it may waken especially with these earthquakes and possible 2012 scenario
The best-known eruption of Krakatoa culminated in a series of massive explosions on August 26–27, 1883, which was among the most violent
volcanic events in modern and recorded history.
With a Volcanic Explosivity Index (VEI) of 6,[3] the eruption was equivalent to 200 megatons (MT) of TNT—about 13,000 times the nuclear yield of the
Little Boy bomb (13 to 16 kT) that devastated Hiroshima, Japan during World War II and four times the yield of the Tsar Bomba (50 MT), the largest
nuclear device ever detonated.
The 1883 eruption ejected approximately 21 cubic kilometres (5.0 cu mi) of rock, ash, and pumice.[4]
The cataclysmic explosion was distinctly heard as far away as Perth in Western Australia, about 1,930 miles (3,110 km) away, and the island of
Rodrigues near Mauritius, about 3,000 miles (5,000 km) away.[5]
Near Krakatoa, according to official records, 165 villages and towns were destroyed and 132 seriously damaged, at least 36,417 (official toll) people
died, and many thousands were injured by the eruption, mostly from the tsunamis that followed the explosion. The eruption destroyed two-thirds of the
island of Krakatoa.
Eruptions at the volcano since 1927 have built a new island in the same location, named Anak Krakatau (Indonesian: "Child of Krakatoa"). This island
currently has a radius of roughly 2 kilometres (1.2 mi) and a high point around 300 metres (980 ft) above sea level, growing 5 metres (16 ft) each
year.[6]
wiki
it would be absolutely devastating if this were to occur, and i hope it doesn't, i love indonesia
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