Latest Geology of British Columbia Stories

A comprehensive analysis of the Cascadia Subduction Zone off the Pacific Northwest coast confirms that the region has had numerous earthquakes over the past 10,000 years, and suggests that the southern Oregon coast may be most vulnerable based on recurrence frequency. Written by researchers at Oregon State University, and published online by the U.S. Geological Survey, the study concludes that there is a 40 percent chance of a major earthquake in the Coos Bay, Ore., region during the next...

Every 15 months or so, an unfelt earthquake occurs in western Washington and travels northward to Canada's Vancouver Island. The episode typically releases as much energy as a magnitude 6.5 earthquake, but it does so gradually over a month.New technology is letting University of Washington researchers get a much better picture of how these episodic tremor events relate to potentially catastrophic earthquakes, perhaps as powerful as magnitude 9, that occur every 300 to 500 years in the...

The major earthquakes that devastated Chile earlier this year and which triggered the catastrophic Indonesian tsunami of 2004 are more than just a distinct possibility to strike the Pacific Northwest coast of the United States, scientists say.There is more than a one-in-three chance that it will happen within the next 50 years.New analyses by Oregon State University marine geologist Chris Goldfinger and his colleagues have provided fresh insights into the Northwest's turbulent seismic history...

Link to earthquakes unclear, but tremors seem to increase stress on shallower fracture zoneThe faint tug of the sun and moon on the San Andreas Fault stimulates tremors deep underground, suggesting that the rock 15 miles below is lubricated with highly pressurized water that allows the rock to slip with little effort, according to a new study by University of California, Berkeley, seismologists."Tremors seem to be extremely sensitive to minute stress changes," said Roland...

A spike in mysterious underground rumblings observed on a section of the San Andreas fault near Parkfield, California, could indicate a build-up of stress and an increased likelihood of a major earthquake, said scientists at the University of California, Berkeley.The researchers monitored seismic activity along a heavily instrumented segment of the central San Andreas Fault from July 2001 to February 2009, and recorded more than 2,000 tremors lasting from minutes to nearly half an...

A new study evaluates expected ground motion in Seattle, Victoria and Vancouver from earthquakes of magnitude 7.5 - 9.0, providing engineers and policymakers with a new tool to build or retrofit structures to withstand seismic waves from large "subduction" earthquakes off the continent's west coast.The Cascadia subduction zone in the Pacific Northwest has produced great earthquakes of magnitude 9.0 and larger, most recently in the 1700s. Now home to millions of people and a vast...

Seattle's tallest buildings are at risk of collapse during a rupture of the Cascadia fault zone in the Pacific Northwest, say U.S. seismic experts.The Cascadia subduction zone is likely to produce the strongest shaking experienced from earthquakes in the lower 48 states, said seismic experts from the California Institute of Technology in Pasadena.While the Pacific Northwest has experienced little seismic activity in 200 years, there is growing consensus the Cascadia subduction zone ruptures...

Researchers are using modern technology to study "silent earthquakes" along a major fault zone beneath the Nicoya Peninsula in Costa Rica. Also known as slow slip events, they involve the same motion as an earthquake, but they occur so slowly that they can only be detected by networks of modern instruments.Scientists are using a network of 13 Global Positioning System (GPS) monitoring stations and 13 seismic stations to measure precisely the movements of the Earth's crust on the...

CORVALLIS, Ore. "“ The magnitude 9.2 earthquake that triggered a devastating tsunami in the Indian Ocean in December of 2004 originated just off the coast of northern Sumatra, but an "energy pulse" "“ an area where slip on the fault was much greater "“ created the largest waves, some 100 miles from the epicenter. Seismologists have mapped these energy pulses for Sumatra and are trying to learn more about them to predict better when and where tsunamis may occur. They also hope...

Stories of two-headed serpents and epic battles between Thunderbird and Whale, common among Northwest native peoples, have their root in the region's seismic history. New research led by a University of Washington scientist has found stories that could relate to a large Seattle fault earthquake around A.D. 900 and specific eyewitness accounts linked to a mammoth 1700 earthquake and tsunami in the Cascadia subduction zone. The stories come from people living in areas from northern California...