Scientists Find Cause of Oregon Earthquakes

Scientists say a group of previously unknown faults was behind an odd swarm of earthquakes last year off the Oregon Coast. But just what set them off remains unknown.

Oregon State University marine geologist Robert Dziak (ZEE-ack) says the discovery about 140 miles off Newport suggests the Juan de Fuca Plate is still actively converging with North America in the Cascadia Subduction Zone.

He adds that they do not know what triggered the quakes, and it is not clear if they represent a normal release of stress within the plate, or something else.

Using a network of underwater microphones, scientists recorded some 1,600 quakes over two months. Most were between magnitude 3.0 and 4.0, but a few exceeded magnitude 5.0.

Latest Comments

• October 28, 2009 at 4:07 am

  Old Pro says:

  'Nuff said. You all know that Global Warming" is the proximate cause, and George W. Bush was the initiator!!
• October 28, 2009 at 2:30 am

  fred says:

  my guess is there was some sort of seismic activity in the area in the pacific plate and adjacent faults in that area that caused those pesky quakes. Gosh, I hope no one spent... read more