Experts: L.A. Quake Fault "Capable of Massive Temblor"

KTLA News ^ | March 18, 2010

[Touch Not the Cat]

The moderate earthquake that struck the Los Angeles area Tuesday likely occurred a long a fault that could generate a much stronger, major quake in the future, according to scientists.

Seismologists say the Puente Hills thrust system could touch off earthquakes up to magnitude 7.5 directly underneath downtown Los Angeles. Such temblors would prove larger than any in the modern history of the Los Angeles Basin.

The Puente Hills fault, which winds through the area's fractured underbelly for about 25 miles -- from northern Orange County to Beverly Hills -- has generated at least four earthquakes ranging from magnitude 7.2 to 7.5 in the last 11,000 years, according to a study published in the journal Science.

"The bad news," the report said, "is that when the Puente Hills thrust fault ruptures in an earthquake, it tends to do so in a very big way."

Tuesday's magnitude-4.4 quake struck at 4:04 a.m. and was centered 1 mile east-northeast of Pico Rivera, according to the U.S. Geological Survey.

There were no reports of serious damage or injuries.

Residents as far away as San Diego and Santa Clarita reported feeling the quake, which consisted of some rumbling and a quick jolt.

Seismologists have not determined which fault was responsible for Tuesday's shaker, however, Daniel Ponti of the U.S. Geological Survey told the Whittier Daily News that it was likely on the Puente Hills thrust system.

[winoneforthegipper]

Thanks for the Ping.

[winoneforthegipper]

Though this fault line is not a subduction zone it does have an element that was not present in Chile.

This Whittier fault line is capable of producing what is called a “Super Shear” earthquake, where by the “Shear” or S/waves are channeled is such a way as being able to over take each other. What causes this is that the waves actually break the sound barrier while they are propagating outward from the fault quake.

There is much debate on what this actually means to the overall resulting damage from a quake, but it is thought that it holds the key as to why in some slip/strike earthquakes of the same magnitude, the damage is not.

[Quix]

Fascinating.

I’m wondering . . . would you and your cohorts be able to conjecture productively about . . .

ASSUME that a massive, long mountain ridge is to appear with great suddenness over much of the length of California . . .

where

would you expect such a thing . . . and to run from where in the South to where in the North?

And where might subsidence or sinking be on the West and/or East of such a rising ridge?

[Steve Van Doorn]

my wife is going to love that tape.

[gathersnomoss]

One of my favorites as a young teen.

[BenLurkin]

IIRC the Pacific Plate is the one that is rising. A large quake along the San Andreas fault (which is mostly in or east of the San Gabriel Mountains) would lift the L.A. side up about 12 feet.

[DollyCali]

whoa.. very scary & very probable. Not if, just when

[winoneforthegipper]

For the most part the Pacific Plate and the North American Plate in the California region anyways is considered a transform Boundary, so a single earthquake most likely would not result in a trench or a rise of any significance.

However, Quix I will answer your question in another post shortly.

[Quix]

I assume it would be a series of quakes—likely in rapid succession.

One source asserts that observers in the right place will be able to see mountains of a considerable height rise rapidly as they watch.

A pretty dramatic prediction.

I’ve long expected things that dramatic in the end times but have never run across anyone else who thought anything remotely like that . . . until the last several months.

[Quix]

Am curious what leads you to that conclusion. I haven’t ran onto many who have our perspective.

[winoneforthegipper]

I don't have much time this evening to give you maps and things but I will eventually...lol

I did want to respond because I have been looking at this for a few weeks, and this looking intensified a bit yesterday on that whole directional rotation that is observed in Oregon and a good part of Washington.

Anyways there is a fault line that intrigues me in Oregon called the OatField fault, which is part of the Portland Hills fault system.

I have not done all that is required to confirm the possibilities but I think this following scenario might just be the next geological change we see on the west coast.

Imagine From the Puget Sound down to Portland Channel then extending southwestward a new trench, filled with water. A new Island or two...lol

I will try to get more into this later this evening or perhaps tomorrow morning. I really do think the plate tectonics could support such a scenario.

Now will it ever happen, no but there is more of a chance this would happen than Nevada being beach front again.

[Quix]

I wouldn’t think it would be a single quake either—but several in rapid succession.

Then there’s the Hopi map here:

http://www.standeyo.com/index1.html

Thanks for your reply about the Wash Oregon thing.

Interesting.

Take your time.

LUB

[Quix]

Joe, how easy would it be to impose a State boundary lines map on top of this Hopi map???

http://www.standeyo.com/index1.html

[DollyCali]

absolutely NOTHING scientic.. (just too many sci fi movies I guess) :-)

[Quix]

These days

fiction

is more likely to be accurate than the MSM.

[Quix]

Article on huge magma chamber discovered under Western Wash . . . with very interesting links to other more professional articles:

http://www.abovetopsecret.com/forum/thread552156/pg1

Giant Pool of Magma Under Washington StateIt may be the largest ever discovered on the continent

http://news.softpedia.com/news/Giant-Pool-of-Magma-Under-Washington-State-125262.shtml

Geologists recently announced that there might be more things that Mount St. Helens, Mount Rainier and Mount Adams have in common, other than the fact that they are all volcanoes. Preliminary studies seem to indicate that they draw their lava from the same enormous magma pool that spans the entire southwestern portion of Washington state. The science team that conducted the investigation revealed in the October 25 issue of the journal Nature Geoscience that the setup in Washington might be similar to the one known to exist under the Yellowstone supervolcano, LiveScience reports.

“If confirmed by additional methods, this could be one of most widespread magma-bearing areas of continental crust discovered thus far,” the journal entry reads. The leader of the new investigation was geologist Graham Hill, from GNS Science, in New Zealand. He and his team used advanced measuring techniques to assess the electrical conductivity of rocks that lay beneath the northern Cascade Mountain range, and discovered that previous speculations, which held that a layer of low electrical conductivity permeated the entire region, were true. The three volcanoes are indeed connected.

The team’s measurements led the experts to conclude that “fingers,” or filaments, from this layer headed towards the surface, just underneath Mount St. Helens, and Mount Adams. The lower electrical conductivity, geologists know, is characteristic of regions rich in molten rock, as hard rock conduces electricity far better than magma does. The investigation therefore seems to hint at the fact that, under the continental crust, a large pool of semi-molten rock may have formed, spanning the area below all the three volcanoes. These filaments may be contributing to an increased level of volcanic activity.

“Their interpretation is open to disagreement. Other geophysical studies don’t support this theory,” Seth Moran says, quoted by McClatchy Newspapers. The scientist is a volcano seismologist with the US Geological Service (USGS) Cascades Volcano Observatory, in Vancouver, Washington. A significant number of new studies has forwarded in the past few months our understanding of supervolcanoes. Especially useful was the discovery of a new supervolcano in the Italian Alps, which last blew its top off some 280 million years ago.

Knowing as much as possible about volcanoes is crucial, as the US has Yellowstone on its territory. If the massive mountain explodes, it could cover over half of the country’s surface in three feet (one meter) of ash, and cause an unbelievably large damage, according to a study. It’s currently estimated that the supervolcano erupts once every 600,000 years, so, for now, we are safe, but the Earth’s magma flows can be unpredictable, scientists say.

[Quix]

And:

http://www.bellinghamherald.com/2009/10/26/1127403/controversial-study-suggests-vast.html

magma chamber location (map):

http://media.mcclatchydc.com/smedia/2009/10/23/17/20091023_MAGMA_map.large.prod_affiliate.91.jpg

[Steve Van Doorn]

this is different then a caldera?

[Quix]

As this ignorant layman understands such things . . .

a caldera is a large . . . usually oblong/oval . . . area miles in dimensions which was once the site of a huge eruption spewing many cubic miles of material usually high into the atmosphere in a super volcano eruption.

I suppose some caldera are not super volcano sized.

There are often smaller eruptions in the same caldera after the main huge one originally forming it.

The caldera may form a rough bowl/depression shape . . . though there’s usualy ages enough of erosion, later smaller eruptions and perhaps other quake related deformations along with the vast size . . . and altered, quite varied landscape within them . . . that many caldera were not perceived to be caldera initially.

I think that’s about all I have off the top of my head. Perhaps someone that knows what I’ve tried to talk about much better can correct me.

[Quix]

Oh, the caldera is on the surface . . .

the magma or magma plume is usually quite deep . . . sometimes coming nearer the surface in the case of volcanoes.

. . . particularly say in Hawaii.