"Cascadia is America's own tectonic version of Sumatra, where the magnitude 9.3 earthquake and tsunami of 2004 occurred. Stretching off the Pacific shore from northern California some 1300 kilometers to the tip of Vancouver Island, the Cascadia subduction zone appears capable of its own magnitude 9 earthquake. What do we know about its behavior and its history? What would that great Cascadia earthquake be like?"
The Great Cascadia Earthquake of 2xxx

There is a possibility that one of the future GREAT earthquake's the world will see, in the near future, will come from the Cascadia region of North America, and that it will originate with the Juan de Fuca plate.

Since 2005 there has been a series of ongoing "creeping" earthquakes taking place within the subduction zone of the Juan de Fuca plate.

Two weeks prior to February 2, 2007, scientists in Canada began picking up "...an unusual travelling tremor deep inside the earth’s crust." 

"Herb Dragert, a researcher with the Geological Survey of Canada in Victoria, said the wandering tremor is the result of subtle, slow slippage of the Juan de Fuca plate as it pushes against the North American plate in an area known as the Cascadia subduction zone. 

A sudden slippage of the two plates would trigger an earthquake similar in magnitude to the one off the coast of Sumatra on Dec. 26, 2004 that killed more than 300,000 people." 
Earthquake scientists detect plate slippage

Late in the evening on February 2, 2007 CTV.ca in Canada issued a warning about a window of increased earthquake activity, based on research being done by Canadian earthquake experts:
"Experts warn that British Columbia's south coast has entered a two-week window of increased probability in which a major earthquake could occur.

While the chances of that happening are still very slim, such an event could trigger a tsunami equal to the size and the strength of what hit the Sumatra-Andaman Islands in 2004.

Seismologists with B.C.'s Geological Survey of Canada made the announcement after measuring a series of minor tremors deep below the Earth's surface and along the Cascadia Subduction Zone -- a long, sloping fault that stretches from northern California to Vancouver Island.

The zone, which separates the Juan de Fuca Plate and the North American Plate, has a very large fault area which can produce large earthquakes with a magnitude of 9.0 or greater if a rupture were to occur.

"Where the Juan de Fuca plate is subducting beneath the North American plate, and where those plates are touching, it's locked," earthquake seismologist Alison Bird told CTV.ca."
B.C. enters window of increased quake risk

Late in the evening February 3, 2007, and early in the day February 4, 2007, stories started circulating that the 'silent' earthquake tremor traveling deep inside the subduction zone had suddenly stopped and the earthquake danger was over. Later in the day, February 4, 2007, Canadian news stories were once again circulating about an open window of increased earthquake activity for the southern part of British Columbia.

One of the troubling parts about the news story, is that there is hardly any mention of the risk facing areas in the U.S. It appears the media in the U.S. is being silenced; being told not to carry the story. Those in the Pacific Northwest, on the United States side, are equally at risk should a GREAT earthquake strike the region, yet, the American people for the most part are not being told about the heightened risk they are facing. 

Is pressure being put on the Canadian geological services to silence, or lessen the danger risk? It has happened in the past with other geological services, such as the European Mediterranean Seismological Centre, so it is possible with Canada. 

There are a lot of 'jack boots' working for the U.S.G.S. and the U.S. Government these days, and they don't like it when one of the other geological services says and does things that don't conform with the 'god-like' manner (we are superior to you attitude) of the U.S.G.S.

Similar types of disinformation surfaced when a massive tectonic movement took place in Indonesia on November 2, 2002, just a day before the massive Denali, Alaska earthquake inflicted a visibly big surface tear through Alaska. 
Details: 
The Earthquake Event of November 2002 - Forerunner of the GREAT Indonesian EQ (Earthquake) 

Denali, Alaska earthquake information: 
 http://www.aeic.alaska.edu/Denali_Fault_2002/

A massive earthquake may, or may not, strike the Pacific Northwest - southern British Columbia region in the time period being predicted, but it is going to happen. It is not a matter of IF it is going to happen, it is only a matter of WHEN it is going to happen. With geological and climate instabilities increasing around the globe at a heightened pace, the event is likely to happen sooner rather than later. 

The climate instabilities risk was added, because the melting glaciers and ice caps are adding water to the oceans, which is in turn is adding an increased weight load, and this is a situation that is further weakening already weakened tectonic plates. This in turn causes increased geological instabilities around the world. It is one natural system impacting another natural system, and one of the reasons global climate changes are such a danger.

The Pacific Northwest - southern British Columbia Cascadia region continues to be an area at risk from a GREAT earthquake. An earthquake that will in turn very likely cause a catastrophic tsunami, and very possibly set off a chain of volcanic eruptions on a scale not seen in modern recorded history.
 

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 Earth Changes Central

April 17, 2009
The Economist

Easels holding seismic maps of Italy are standing all around the western headquarters of the United States Geological Survey in Menlo Park, California. Given that Californians live in permanent fear of “the big one”, they feel “lots of scientific and emotional connections” to Italy’s recent earthquake, which killed 294 people and destroyed ancient towns, says Ross Stein, a scientist there.

America’s entire western coast sits on or near tectonic faults. Since these forces formed the coast’s harbours, and since people have settled largely around those harbours, the populations tend to be where the risks are highest.

In California, which has about 1,500 known faults, two are particularly menacing. One is the southern San Andreas, where the Pacific plate shears north-west along the North American plate, and where a “swarm” of tremors under a desert lake near the Mexican border has recently caused worry about a bigger quake being triggered near Los Angeles.

The other is the Hayward fault that cuts through Oakland, Berkeley and the rest of the Bay Area east of San Francisco. It has ruptured on average every 140 years for the past 700 years; the last big one was just over 140 years ago. Depending on the time of day, location and depth of a quake, Mary Lou Zoback, an earthquake specialist at Risk Management Solutions, a firm that produces loss scenarios for insurance companies, reckons that a magnitude 7.05 rupture in the Hayward fault could kill 4,500, injure 50,000, leave hundreds of thousands homeless and cause $250 billion in economic loss, most of it uninsured.
Click here!

Oregon, Washington and British Columbia might worry too. Their region, called Cascadia, is the result of another plate, the Juan de Fuca, shoving underneath the North American. These faults produce big ones about every 500 years, less frequently than California’s. But when they do, the shaking is otherworldly. The last giant, in 1700, was of magnitude nine, which has the energy of about 31 eights, 1,000 sevens, or 30,000 sixes. (This month’s quake in Italy measured 6.3.)

The best way to prepare is to build safer structures, says Jeanne Perkins, who advises local governments in the San Francisco Bay Area. One difference between California and Italy, she says, is that its cities and buildings are younger. Building codes have progressed with each quake, taking big leaps after tremors in 1971, 1989 and 1994. They also seem to be enforced.

Brick buildings have been the deadliest in the past, and are now rare in California, though still common in Oregon and Washington. Wooden houses fare relatively well because they are flexible and light. Office buildings used to be dangerous, but many have now been retrofitted.

The biggest worry, says Ms Perkins, is so-called “soft-storey” residential blocks that predate the recent building codes. These are buildings that have parking garages, restaurants or shops on their ground floors, with few load-bearing walls holding up the flats above. She estimates that about 2,800 residential blocks in San Francisco have soft storeys, and about 1,500 in Oakland. Often these contain rent-controlled flats, raising fears that the poor would be more likely to die.

Mr Stein in Menlo Park urges perspective. He has spent $5,000 retrofitting his own house, keeps his survival kit up to date and has clipped whistles on his and his daughters’ key chains (“the best thing if you’re trapped”). But he enjoys life on the sun-kissed coast. Besides, he winks, “my cappuccino machine is on a separate, uninterruptible, power supply.”

 http://www.economist.com/world/unitedstates/displaystory.cfm?story_id=13496828 
 

"Some researchers have found that the combined effect of the Sun and Moon of the syzygies (conjunction and oppositions) is approximately three times as great as the effect produced at quadrature.

Alexis Perrey of Dijon, France, compared soli-lunar positions of almost 24,000 earthquakes between 1751 and 1852. He also learned that quakes of large magnitude often take place soon after the Sun and Moon are in line to the Earth, and when the Moon is in perigee. 12,347 earthquakes occured in syzygy weeks, compared to 11,601 at quadrature.

"They are also more frequent," he said, "when the action of the Sun and Moon on the Earth is in the same direction, and shocks are more numerous when the Moon is overhead than when near the horizon."

A research group from the French Academy later used Perrey’s data to discover something they never expected to find.

"There is a maximum of earthquake activity," one spokesman said, "when Jupiter and Saturn are close to conjunction in the same mean longitudes—265° and 135°." Why this should occur in the signs Leo and Sagittarius more so than in Jupiter-Saturn conjunctions in any other sector of space is still a complete mystery."
 

ASTROLOGY: The Space Age Science
by Joseph F. Goodavage

“Professor Charles C. Conroy, who cooperated with the Weather Bureau office at Los Angeles, described March 10 as an unusually hazy day with temperatures in the upper 70s and above-normal humidity.

“In the late afternoon the air was filled with a peculiar bluish haze resembling a veil of smoke.  At 4:30 P.M. I called the attention of Mark H. Stanley of the Weather Bureau to this phenomenon.  At 4:45 P.M. a sheet of alto-stratus cloud moved rapidly from the West and at 5:10 P.M. had already covered the sky.  The earthquake occurred at 5:54 P.M.  This cloud sheet persisted but thinned gradually after 6:45 P.M., and the Moon shone with increasing brightness in the evening.”

Weather observations and reports, both official and private, indicate peculiar weather or other phenomena of some kind either preceding or occurring during seismic phenomena.  There often seems to be a kind of “earthquake weather” preceding the first shocks.  Birds and animals are known to vacate the premises sometimes days before a quake occurs.  This seems to confirm the idea that subtle, powerful changes are building up in the geomagnetic field as a result of magnetic conjunctions of planets.  It is now established that most, if not all animals are able to tune in” on the earth’s magnetic field.”

ASTROLOGY: The Space Age Science
by Joseph F. Goodavage

Note: Having read this book in late 60's, I personally witnessed this phenomena during the 1971 Quake in Los Angeles.  The Quake occurred at 6:05 AM, still dark, but watched this inky high up in ionosphere cloud dissipate over a couple hours.
 

PAPUA New Guinea has been pummelled by non-stop tidal waves and unusually high tides that have forced 75,000 people from their homes this month, the United Nations says.

The autonomous PNG region of Bougainville, the Solomon Islands, the Marshall Islands and the Federated States of Micronesia were also affected by the high waves, according to the UN Office for the Coordination of Humanitarian Affairs. 

"Half the population of (PNG's) Manus Island has been displaced," OCHA spokeswoman Elisabeth Byrs said. 

"The government of Papua New Guinea has declared a state of national disaster and a team of OCHA experts should arrive Wednesday to examine their needs.

"The fact that the affected islands are scattered and the never-ending nature of the tidal waves make the evaluation of the situation very difficult." 

Australia this week announced it will give $1 million to Papua New Guinea after the high sea swells inundated several provinces. 

The three major tectonic plates off the Pacific Northwest coast are undergoing a gradual shift, and the area in which they converge -- popularly known as the "Triple Junction" -- appears to be migrating in a southeasterly direction.

Image: As the North American crust interacts with the Migrating Mendocino Triple Junction, the crust is first significantly thickened and then equivalently thinned over a distance of a few hundred kilometers (within a time frame of 5 Ma or less). This process of ephemeral crustal thickening is proposed to result from viscous coupling between the northward migrating Gorda (Juan de Fuca) slab and the base of North America south of the triple junction. 

The change isn't a cause for alarm, researchers say; in fact, it has been slowly taking place over millions of years. But advances in technology, and data provided in part by formerly classified U.S. Navy hydrophones, are giving scientists a new perspective on the underlying geology of the region -- an understanding that may change previous accepted models of seafloor spreading, undersea volcanism and, ultimately, seismic hazards.

Findings of the research, conducted by Robert Dziak of Oregon State University, were just published in the journal Geology.

This "reorganization" of the Triple Junction may indicate that the subduction of the northern portion of the Juan de Fuca plate beneath the North American plate may be slowing and eventually cease, Dziak said.

"It appears that it is turning into a transform boundary, where the plates slide past each other instead of 'colliding,'" said Dziak, an associate professor at OSU whose lab is at the university's Hatfield Marine Science Center in Newport. "In many ways, it is becoming more like the San Andreas Fault to the south, where the earthquake danger comes from strike-slip events, rather than a subduction quake.

"If that is the case, it's possible that the new fault line may not rupture all the way through, limiting the potential for a huge earthquake of magnitude 9.0 or higher," Dziak added. "That doesn't mean the Northwest isn't susceptible to a major earthquake. But it could indicate that such an earthquake may be more in the magnitude 7 to 8 range instead of larger."

Dziak compared the present fault lines with ancient fault lines using sonar data collected during 16 different research cruises over the past 23 years. Slight changes in the overall motion of the plates influence how they interact, he says, and are leading to the shift.

The Triple Junction is where the Juan de Fuca plate, the North American plate and the Pacific plate converge in an area off the Pacific Northwest coast from Oregon to Vancouver Island. Seafloor spreading associated with the tectonic action created two major ridges, the Juan de Fuca Ridge to the south and the Explorer Ridge to the north.

Over long periods of time -- literally millions of years -- these ridges have gradually reoriented themselves and formed an independent plate called the Explorer plate, which sheared off the Juan de Fuca plate and slowly has been subducting beneath Vancouver Island. The plate, about 200 kilometers in length, is subducting beneath the North American plate at the rate of about 4.3 centimeters a year.

Eventually, Dziak said, the Explorer plate will disappear.

"It is a small plate, caught between the two larger plates," he explained. "It's an example of the segmentation that is taking place that may be changing the seismic hazard profile of the entire region."

To evaluate that seismic hazard, Dziak and his colleagues at OSU's Hatfield Marine Science Center have used a hydrophone system called the Sound Surveillance System to "listen" for subtle earthquakes offshore. SOSUS, as it is known, was used by the U.S. Navy during the Cold War to monitor submarine activity in the northern Pacific Ocean. As the Cold War ebbed, these and other unique military assets were offered to civilian researchers performing environmental studies.

When they first started using SOSUS, the researchers discovered that there were literally thousands of earthquakes taking place off the coast that had never been monitored. The frequency of these quakes -- most falling in the magnitude 2 to 4 range -- initially stunned researchers because they weren't being detected on land, even by the most sensitive seismometers. These small quakes occurred daily, but every so often there would be a "swarm" of as many as a thousand quakes in a three-week period.

"In the last 10 years, I've seen seven of these swarms," Dziak said. "The plate doesn't move in a continuous manner and some parts move faster than others. When it gets caught up and meets resistance, these swarms occur and when they do, lava breaks through onto the seafloor.

"Usually, the plate moves at about the rate a fingernail might grow -- say three or four centimeters a year," he added. "But when these swarms take place, the movement may be more like a meter in a two-week period."

The SOSUS data are only 15 years old, so it is difficult to determine how the long-term effects of changes in the tectonic plates affect shorter-term seismic activity. There is no indication how these swarms of small quakes may be related, if at all, to the possibility of a major earthquake. Compared to the Indian Ocean, for example, the Northwest's Cascadia Subduction Zone is seismically "quiet" on a year-to-year basis, though there are indications the region may have had several large earthquakes in the past.

"We still have a lot to learn," Dziak said. "The Juan de Fuca is one of the most actively monitored tectonic plates on the planet, yet we are learning new things about it every day. And we still have a lot more to learn before we can pinpoint exactly what our hazard situation really is."
 http://www.sciencedaily.com/releases/2006/04/060417110331.htm

Swarm of Earthquakes Detected Off Oregon
 

Apr 11, 9:04 PM (ET)

By JEFF BARNARD 
sponsored links 
 

GRANTS PASS, Ore. (AP) - Scientists listening to underwater microphones have detected an unusual swarm of earthquakes off the central Oregon Coast. 

Scientists don't know what the earthquakes mean, but they could be the result of magma rumbling underneath the Juan de Fuca Plate - away from the recognized earthquake faults off Oregon, said geophysicist Robert Dziak of the National Oceanic and Atmospheric Administration and Oregon State University's Hatfield Marine Science Center in Newport, Ore. 

They hope to send out the OSU research ship, Wecoma, to take water samples, looking for evidence that sediment on the ocean bottom has been stirred up and chemicals in the water that would indicate magma is moving up through the crust, Dziak said. 

There have been more than 600 quakes over the past 10 days in a basin 150 miles southwest of Newport. The biggest was magnitude 5.4 and two others were more than magnitude 5.0, OSU reported. They have not followed the typical pattern of a major shock followed by a series of diminishing aftershocks, and few have been strong enough to be felt on shore. 

It looks like what happens before a volcanic eruption, except there are no volcanoes in the area, Dziak said. 

The Earth's crust is made up of plates that rest on molten rock, which are rubbing together side to side and up and down. When the molten rock, or magma, erupts through the crust it creates volcanoes. That can happen in the middle of a plate. When the plates lurch against each other, they create earthquakes along the edges of the plates. 

In this case, the Juan de Fuca Plate is a small piece of crust being crushed between the Pacific Plate and North America, Dziak said. 

On the hydrophones, the quakes sound like low rumbling thunder and are unlike anything scientists have heard in 17 years of listening, Dziak said. Some of the quakes have also been detected by earthquake instruments on land. 

The hydrophones are leftover from a network the Navy used to listen for submarines during the Cold War. They routinely detect passing ships, earthquakes on the ocean bottom and whales calling to each other. 

Date: 2004-07-15 
 

'Anti-plume' Found Off Pacific Coast
CORVALLIS, Ore. – The gradual subduction of the Juan de Fuca plate beneath the North American plate puts tremendous stress on the seafloor, creating cracks and fissures, hydrothermal vents, seafloor spreading, and literally hundreds of small earthquakes on a near-daily basis.

Now a North American team of scientists has documented for the first time a new phenomenon – the creation of a void in the seafloor that draws in – rather than expels – surrounding seawater. 

They report their discovery in the July 15 issue of the journal Nature.