Sunday, January 25, 2015

January 26 Shake It

The Bright Lights series is usually about building things. Tonight it is a discussion of what Portland would be like after the big earthquake.

About every 200-900 years, the tectonic plate we sit on, the North American Plate, slides over the Juan de Fuca plate off our coast as it is driven East by upswelling at its juncture with the Pacific plate. The last time was January 26, 1700 at 9PM. It is a subduction fault which generates megathrust earthquakes of greater than 9.0 and tsunamis. The under layer is locked by friction with the over layer. Once there is enough pressure, it slips.

The Fukishima (Tōhoku) earthquake was a megathrust. Not only was it great in magnitude, it lasted for a long six minutes. The Sumatra–Andaman earthquake, creating the great Pacific tsunami in 2004, lasted for 10 minutes. It's not clear that any modern construction will be able to withstand a strong, long earthquake unharmed.

Beyond building physics, there is the human response.

For a discussion of that Carmen Merlo, Portland’s director of emergency management and Joe Zehnder, Portland’s chief planner speak this evening.

Portland earthquake discussion at the Mercy Corps Action Center 28 SW 1st. 7PM Free