Any parent of a rambunctious youngster can tell you trouble might be afoot when things go quiet in the playroom. Two independent research initiatives indicate there is a comparable situation with the Cascadia earthquake fault zone.
Research geologists just finished a field trial to test a less invasive way to complete seismic hazard surveys. The federal scientists attempted to map an earthquake fault under Seattle simply by listening for underground echoes from all the noise we humans create at the surface.
This week a research ship is retrieving dozens of seismometers that have spent the last year on the ocean floor off the Northwest coast. Earthquake scientists hope the data they're about to get will shed more light on the structure of the offshore Cascadia fault zone. That plate boundary will be the source of the Big One whenever it rips.
Parts of Washington and Oregon are in the midst of silent earthquakes this week. You can't feel this so-called "slow slip" quake and it doesn't cause damage. Still, scientists want to learn more about the recently discovered phenomenon.