But for earthquake scientists, it was a kind of Holy Grail, perfectly illustrating the seismic forces at work underneath this Bay Area neighborhood. The historic Hayward City Hall was closed because it sits directly on top of the Hayward fault, which is pulling the building apart. (Rong-Gong Lin II / Los Angeles Times )Cracks in the historic Hayward City Hall are formed by the slow, persistent movement of the Hayward fault. Since at least the 1970s, scientists have painstakingly photographed the curb as the Hayward fault pushed it farther and farther out of alignment. It has been 148 years since the Hayward fault last ruptured, unleashing a huge earthquake.

Source: Los Angeles Times July 05, 2016 18:23 UTC