The Beginner's Guide to Earthquake Risk

October 19, 2015

In our area of the country, the risk of an earthquake is never far from our minds. In areas along the San Andreas Fault line in California, the earth has a way of nudging people awake anytime we feel complacent.

We have been relatively lucky, as truly devastating earthquakes on the level that we have seen in recent years in China, Mexico, Japan and Haiti, involving thousands and even hundreds of thousands of deaths -have been rare.

That's due to a combination of California's strenuously enforced building codes - and pure dumb luck. Yes, we have had several quakes of 9+ magnitude strike low-populated areas of Alaska over the years. But as of this writing, we have not had a major metropolitan area host the epicenter of a 7.8 magnitude-plus earthquake in living memory.

But that could change anytime.

The Federal Department of Emergency Management has developed a threat matrix to help gauge your exposure to earthquake threats.

In addition, FEMA has also published maps to help you determine your proximity to fault lines, which are areas with an elevated likelihood of a seismic event.

You can download the maps from FEMA at

The map is relatively easy to read; The closer you are to a red area on the map, the greater your exposure. But the damage you will incur has a lot to do with the strength of your building as well.

FEMA divides the map into five basic zones, and designates them as threat levels A through E, (white" through "red.")

As you can see on the map, we don't have any "white" areas in California.

Your exposure to risk becomes significant in "yellow" areas. These areas can extend a considerable distance from the fault line. If you are in a yellow zone, a strongly fortified modern building will likely withstand the shaking with minimal damage. But poorly-built structures are at substantial risk of significant damage and could be totally written off.

As you move further through the color scale, your risk becomes critical in "red" areas. This is alot of us. Poorly-built buildings have a high likelihood of collapse or irreversible structural damage. Both of there resulting in a total loss of the building. Even moderately well-built buildings are at risk of collapse or substantial damage. Only the most robust buildings should be considered safe, and even these may well incur substantial structural damage. Buildings can be shaken off of their foundation, and some buildings will be completely destroyed by the quake.

Protecting Yourself and Your Property

The first step should be obvious: Do not skimp on construction quality or building to code. Earthquakes of magnitudes that killed tens of thousands in other countries have not had that effect so far in the United States in living memory, in large part, because of our strong building enforcement in the United States.

Second, if you are in an earthquake danger zone, locate valuable resources - especially people - in solid and well-constructed buildings designed with earthquakes in mind. You can start over if you have a warehouse full of lumber collapse from an earthquake. Having a building full of people collapse is another scenario altogether. No insurance check ever written can compensate a business for that kind of loss.

Third, get earthquake insurance - and keep your policy updated.

A regular homeowners or business policy will NOT cover you for damage or loss from earthquakes. You must obtain separate coverage specifically to cover earthquake damage - just as those who live in a flood plain must carry separate flood insurance.