It's been a busy summer on the high seas for researchers trying to figure out the inner workings of an ominous earthquake fault. The Cascadia Subduction Zone runs offshore from Vancouver Island to Northern California. When it rips, we could have a magnitude 9 catastrophe.
University of Washington geophysicist Paul Johnson led a nearly month-long research cruise to the likely epicenter for the Big One. His ship carried an unmanned minisub to probe the seafloor directly over the still somewhat mysterious Cascadia earthquake fault.