Next Great Quake: Drilling the San Andreas Fault for Answers

Richard A. Lovett
for National Geographic News
April 17, 2006

In dusty California hills geologists have drilled miles into the Earth to monitor earthquakes where they begin. It's all part of an effort to better prepare the state for the type of megaquake that struck San Francisco a hundred years ago tomorrow.

The scientists are using techniques borrowed from the petroleum industry, but they're not searching for oil. Rather, they're hoping to learn the secrets of the San Andreas Fault's "earthquake machine."

The project is called SAFOD—short for the San Andreas Fault Observatory at Depth. Funded by the National Science Foundation, SAFOD reached a major milestone last year when a 7-inch-wide (18-centimeter-wide) borehole was drilled sideways through the fault zone at a depth of about 2 miles (3.2 kilometers).

Capturing Quakes

Most people have never heard of Parkfield (map), the central California village that is SAFOD's epicenter. But it's famous among seismologists.

The tiny town lies along a segment of the San Andreas Fault notorious for producing frequent earthquakes, ranging in size from magnitude 6 to tremors noticeable only on the most delicate instruments.

(Learn more about how quakes occur with our interactive supersite.)

That makes Parkfield the best place along the fault to "capture" an earthquake in action, say scientists who have been studying the region since the 1980s.

And while the tremors observed here are much milder than the one that may someday do Katrina-like damage to San Francisco, seismologists hope their studies will teach them how to spot the warning signs of potential monster quakes.

(See "San Francisco's 1906 Quake: What If It Struck Today?")


Nobody knows what the project will find, because nobody has ever studied earthquakes in this way.

Continued on Next Page >>




NEWS FEEDS     After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.   After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS

National Geographic Daily News To-Go

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.
Click here to get 12 months of National Geographic Magazine for $15.