When one considers California and the earthquakes risks within the state it may initially be hard to understand why so many people would settle in the state. The Pacific and North American plants grind against one another through the entire state and the San Andres fault is one of the most earthquake prone fault in the world.

But then one considers the fact that fault subductions create natural harbors and scenic mountains and it is easy to understand up many, no matter the risk, would choose to live in California.

But risk the state does pose. With Italy’s most recent earthquake, which killed 294 people, Californians are once again thinking about “The Big One.” Almost everybody in the state, from the geologists to the layman, expect the state to be hit by another large-scale earthquake. The last major quake hit San Francisco in 1994.

What Californians fear is not just any quake, but an expected “Big One” that may hit southern or northern California, or both.

There is the Hayward fault along the northern Bay Area [San Francisco, Oakland and Berkeley] that has ruptured about every 140 years over the past 700 years. The last time the Hayward fault ruptured was a little over . . . 140 years ago.

If the Hayward fault would rupture now at a magnitude of 7.05, one scenario has it that around 4,500 people would be killed. A further 50,000 would be injured. Hundreds of thousands would be left homeless and the economic damage [mostly uninsured] would total $250 billion.

What can California due to prepare?

The best way to prepare is to build safer structures, says Jeanne Perkins, who advises local governments in the San Francisco Bay Area. One difference between California and Italy, she says, is that its cities and buildings are younger. Building codes have progressed with each quake, taking big leaps after tremors in 1971, 1989 and 1994. They also seem to be enforced.

Brick buildings have been the deadliest in the past, and are now rare in California, though still common in Oregon and Washington. Wooden houses fare relatively well because they are flexible and light. Office buildings used to be dangerous, but many have now been retrofitted.

But do not let this scary you from visiting California.

In case you are interested, this site lets you monitor recent quakes in California. Earthquakes there are a common occurrence, though most cannot be felt and even if so they are very light.

Source: State of fear.