Editing Cascadia subduction zone (section)

===Activity===
In the 1960s, underground fractures were uncovered by oil companies in [[Puget Sound]]. These were believed to be inactive through the 1990s.<ref name = Smithsonian>{{cite magazine|url=http://www.smithsonianmag.com/science-nature/future-shocks-83897640/?no-ist|title=Future Shocks: Modern science, ancient catastrophes and the endless quest to predict earthquakes|magazine=Smithsonian Magazine|author= Kevin Krajick|date=March 2005|access-date=15 July 2015}}</ref>

In the 1980s, geophysicists [[Thomas H. Heaton|Tom Heaton]] and [[Hiroo Kanamori]] of [[California Institute of Technology|Caltech]] compared the generally quiet Cascadia to more active subduction zones elsewhere in the [[Ring of Fire]]. They found similarities to faults in Chile, Alaska, and Japan's [[Nankai Trough]], locations known for [[megathrust earthquake]]s, a conclusion that was met with skepticism from other geophysicists at the time.<ref name = Discover>{{cite magazine|url=http://discovermagazine.com/2012/extreme-earth/01-big-one-earthquake-could-devastate-pacific-northwest|title=The Giant, Underestimated Earthquake Threat to North America|magazine=Discover Magazine|date=13 March 2012|author= Jerry Thompson|access-date=15 July 2015}}</ref>