The Geology behind the coming Hayward Fault Earthquake
Since the year 1315, the longest period of time between five major Hayward Fault earthquakes was 160 years. The average was 138 years. October 21, 2008 was the 140th anniversary of the 1868 Hayward Fault earthquake, a magnitude 6.8. In 2016, we are now at 148 Years! That’s 10 years beyond the average rupture cycle and 12 years before the maximum rupture cycle.
According to government statistics, a quake on the entire Hayward fault could reach magnitude 7.3. It would leave over 155,000 housing units uninhabitable. Over 350,000 people will be displaced. Damage to residential buildings will be $90.4 billion; commercial buildings, another $96 billion. See The Coming Bay Area Earthquake, page 75, by the Earthquake Engineering Research Institute.
For a 12-minute video concerning the Hayward Fault, see this KQED presentation.
On page 10 of Seismic Behavior of Level and Stepped Cripple Walls by Y. H. Chai, it states, “More than half of the $40 billion property losses in the Northridge Earthquake were due to failures of wood frame construction, primarily as a result of the damage or collapse of residential, single-family homes ……………..” Damage from the Hayward Fault will greatly exceed this.
A potential magnitude 9.0 earthquake and devastating tsunami in the Pacific Northwest is threatened by the Cascadia Fault.