Elaine Meinel Supkis
For the last week, I have been watching the West Coast of North America very closely. Today, another major earthquake in the ocean right off shore from Canada at the 10k level clearly show that we just may be seeing a major rift event like the Great Sumatran Earthquake on Boxing Day! This alarming possibility has been increasingly probable since that other quake for the rearranging of the continental plates took a big jerk back then and this put pressure on the Pacific Plate which is slamming into North America. The entire length of California's many fractures have been trembling constantly this last 5 years and the pent up energy along all these systems is tremendous now. Seattle is right in line for a major earthquake, too.
An underwater earthquake of magnitude 6.4 on the Richter scale struck 240 km off the coast of Oregon at 5:37 p.m. Wednesday (0137 GMT Thursday), according to U.S. Geological Survey (USGS).
"So far we have had no reports that the earthquake has even been felt," Bruce Presgrave of the USGS told KNX News, a radio channel in Oregon.
"The tsunami warning centers have not issued any warning for this event," he added.
The mechanism of this quake, the manner in which it shook, was horizontal, making it unlikely to produce a tsunami, according to Presgrave.
I check out the earth every day at the government run geological survey site online. Before the Great Sumatran earthquake that killed a quarter million people I was watching that sector very closely because all the 6.0 quakes that suddenly began, interspaced with many microquakes, too an ominous turn one night. All these quakes were at the 10k level and I was interested as to why this depth was so regular, if we look at the quake charts, the depths can be any range below 10k and on rare occasions, above 10k, very shallow quakes. But the 10 k ones often lead to the biggest terrestrial changes in the landscape. These are the ones that jerk the planet's surface around. So I am presuming the 10k layer represents a key boundary between the inner and outer layers of this planet.
I often say, Mother Nature is the one in control of our fates. She, not some 'gods', rules us. She made us from random atoms floating in the waters of this planet, she made this planet, the star we circle and all the galaxies. She and her evil twin, Lady Luck, rule our futures. Random chance is all about probabilities and Lady Luck probably created the universe itself.
Variations in the sun's output, the random chance of collisions from celestial objects and of course, volcanoes and earthquakes, rule us and made us. Nearly all humans, 96,000 years ago, starved to death when a massive volcano in Sumatra exploded totally and created a long, hard and very cold winter, a very, very long winter, it was, too. It deepened the Ice Ages.
Sumatra is one of the most dangerous places on earth. Yet it is heavily populated because it is also very fertile for when the earth moves and shakes and blows out material from the lower levels, this brings renewed minerals to the surface and all volcanoes in clement climates are clothed in green vegetation.
The latest series of quakes in the Americas are dangerously similar to the great quake which was only 4 years ago and back then, I predicted a mirror quake on the other side of the planet would happen within around 5 years. I suggested back then, the US, seeing the horror of that quake on TV, should review our own systems and take severe measures to protect ourselves. Instead, we were deep within our silly housing bubble and building in very inappropriate places. No one wanted to go back over the existing housing and for example, remove houses sitting on the most dangerous quake zones.
I have lived in California. One can trace some of the world's nastiest points of conflicting interfaces between plates by walking down streets and seeing how curbs are displaced and ripples in the asphalt. Houses and businesses were built right on top of this as if it doesn't exist! The Victorians can be excused in this, they didn't really understand until the long rift shift of the Great San Francisco Quake revealed how much the entire state could jerk in one direction in one second. Fences were suddenly 5' north of the other half of the fence, houses were torn in two, the ground had a long crumpled aspect easily seen in the Central Valley from a distance. They figured out how this sort of works but the idea of plate tectonics was a radical revolution when I was a teenager.
Since then, we now know how this works and the refusal to take plate tectonics into consideration while building continues! Japan puts nuclear reactors all over the place even though they still haven't mapped all the quake zones and a recent quake tore right through one. The states along the entire West Coast should have 'no build' zones chosen by geologists. These long lines of pure death and destruction could be turned into lovely parks with plants that can hold the earth intact while quakes happen. Instead, some of the deadliest zones are highways, offices and homes!
The collapse of the McArthur double decker highway shows us how dangerous this stupid practice is! But then, we all wait for this inevitable event, the sudden movement northwards of the outer edge of an entire continent.
A "strong" underwater earthquake occurred off the coast of B.C. early Saturday morning, registering a magnitude of 6.7.
The quake, the second of three to strike in the same area early this morning, hit at about 3:45 a.m. Pacific Standard Time Saturday, said Guy Urban of the West Coast and Alaska Tsunami Warning Center.
The original quake had a preliminary magnitude of 5.3, Urban told CTV Newsnet.
The outer islands of Alaska have been violently shaking ever since 2004. Starting in the far north, a series of not singlular but group quakes have been moving southwards, step by step. Much of the plate being pushed under the North American continent is doing this at sea so no one notices, no buildings fall. Much of this has been underwater or in sparsely inhabited forests. But the sector running from Vancouver to the end of Baja California is mostly on land and some of which is one of the most densely populated parts of the US.
Hey, what's going on underground around here, anyway?
Tuesday's earthquake beneath Lake Erie -- a mild 3.1 magnitude shimmy felt in some lakeshore communities -- was the 55th recorded quake over 2.0 magnitude in the Buckeye State in the last decade.
That's roughly the same number as in the previous 30 years, according to figures at the Ohio Seismic Network.
"We think Ohio -- especially Northeast Ohio and Lake Erie -- is going through a period of increased seismic activity," said Mike Hansen, coordinator of the Ohio Seismic Network. "Even though we know that we're recording more because we have better equipment than in past years."
Ohio State University geophysics professor Ralph Von Frese went a step further.
"We're the earthquake capital of the Big Ten, at least," he said. "This is earthquake country, and Ohio is situated so that we've experienced more than every state around us."
The stresses building on the West are being felt very far away. The fact that the great rift zone of the Great Lakes is now having micro quakes is alarming. If the West Coast suddenly sees a 1,000 mile long sudden jerk, this causes stresses in the Mississippi valley. Some of the biggest quakes in North America come from this sunken part of the continent. We still don't understand the cause. Even as the Rocky Mountains and the Sierras pile ever higher, the center of the continent is depressed while the East Coast is nearly geologically inert.
They lie on the edge of the province's collective memory like a dream scarce remembered; mythical and elusive, full of meaning and great beauty, yet incomprehensible to the waking mind. Impossible not to marvel at, and revel in, these are the Queen Charlotte Islands, arguably one of the most beautiful and diverse landscapes in the world. This group of islands nestled under the Alaska panhandle is the ancestral home of the Haida - the West Coast Aboriginals who have lived here for thousands of years.
According to Haida legend, Haida Gwaii, as it is now known - is the place where time began. There is an older name for this place, a name that comes from the mists of time and seems to be the most appropriate name of all: Xhaaidlagha Gwaayaai - Islands at the Boundary of the World. Certainly it is not hard to miss the spiritual, even mystical nature of the place. The unusual and abundant flora and fauna that thrive in this Galapagos of the North and the marine and wildlife diversity of the surrounding waters and forests make it an ecological marvel.
The location of the first nest of violent shakes is the Queen Charlotte Islands in Canada. Today's quake just south of here is a certain sign, the shifting of this sector, the whole length, is quite possible. This was no microquake today but in the 6.0+ range, a very dangerous sign. These quakes are not enough to cause the earth's crust to move in any direction. It is rather, like a bucking horse kicking out while standing in place. The horse wants to bolt but can't, yet. A 9.0+ earthquake is when the horse bolts.
The magnetic stripes and age patterns off the west coast of North America are strange in several respects:
Oceanic crust increases in age away from the coast
Magnetic anomalies bend in the Gulf of Alaska
The East Pacific Rise terminates in the Gulf of California. (The ridge segment shown on land is under the Imperial Valley of California. This area is below sea level and underlain by oceanic crust, but is cut off from the sea by the Colorado River delta.)
There is a small ridge off the Pacific Northwest and a subduction zone along the coast. The Cascade Range volcanoes are due to the subduction zone. The small plate between the Pacific and North American Plates is called the Gorda Plate.
These data suggest:
There was once a continuous ridge system off the West Coast.
The West Coast was once occupied by a continuous subduction zone.
Most of the ridge and all the crust on the other side of it has been subducted beneath North America. The small ridge and subduction zone in the Pacific Northwest are the last remnants of these former plate boundaries.
There was once a junction of three ridges in the North Pacific. The anomalies off California tell of east-west spreading, but those off Alaska imply north-south spreading. There must have been an additional ridge to accomodate the differences in plate motion.
The volcanic activity this caused was tremendous. Huge seas of lava flowed over Oregon and Washington states. These states still have huge volcanoes that are very much active. We built cities around them just like Naples in Italy, regarding the dangers of eruptions as a remote possibility. Mt. Versuvius has destroyed whole cities in the deep past which have been dug up by archeologists. Yet people build right next to this very dangerous volcano as if nothing will happen in the future. Humans have a long history of ignoring geology.
Most transform faults occur where oceanic ridges are offset on the sea floor. Such offset occurs because spreading takes place on the spherical surface of the Earth, and some parts of a plate must be moving at a higher relative velocity than other parts. One of the largest such transform boundaries occurs along the boundary of the North American and Pacific plates and is known as the San Andreas Fault. Here the transform fault cuts through continental lithosphere
Of all the most dangerous earthquake zones, this one trumps them all for its violence. For it is a sideways movement. In the Mississippi Valley, it is a dropping movement which can spread devastation but building well-designed structures that can handle this isn't all that hard. But the Californian fault lines move, the the Sumatran subduction zone, violently in opposite directions. Severe restrictions and building codes are required. Builders hate putting in 'invisible' things that make buildings safe which is why we have minimal rules for structures. For example, every single member of my house's internal structure, all the junctions where rafters meet the sills, the joists and frame members meet, have steel ties. On top of this, I put in regular triangulation points so all the parts of the frame are much stronger than a regular house. I figure, if we did this on all houses, this would cost an extra $2,000 which is peanuts, considering all those $500,000 houses! This is the cost of one granite kitchen counter set up!
But we decorate the houses to sell, not survive. Triangulating corners is life and death. Anchoring rafters to the building via straps is very much a life and death issue. This protects from both wind and earthquakes. Yet is it virtually never done. I have repaired houses torn up by earthquakes. I was aghast, looking at the poor anchoring to the foundations, the minimal main beams too light or of the wrong material, holding up houses. Researchers in California have done earthquake design research which is very good but translating their information into reality hits up against inertia and the desire to spend on frills rather than foundations.
We will continue to watch this develop. The earth moves very slowly as she prepares to make big changes in the landscape. But the moment of decision is swift. As fast as an eyeblink and with little direct warning.