Land Rising and Sinking Around San Andreas

Land Rising and Sinking Around San Andreas


The earth is rising and falling along the San Andreas Fault here in California.

That’s the build-up of seismic strain, and a new study is showing the amount for the first time ever.

California’s longest earthquake fault runs right by the Coachella Valley, and so when new information comes out about the San Andreas we listen up.

We spoke with the U.S. Geological Survey, and university professors about these new findings.

"Palm Springs area actually is rising very slowly," said Robert Graves with the Earthquake Hazards Program with the U.S. Geological Survey.

How slowly?

About half a millimeter a year which is less than a penny in thickness, but it adds all up.

"Over the course of 10s or hundreds of years, that amount of motion which is related to the amount of stress that’s the motion that’s building up, that’s what causes earthquakes," said Graves.

Scientists with the University of Hawaii used sophisticated GPS to measure the amount of vertical motion.

"Along the San Andreas Fault, most of the motion is horizontal, the vertical are very small and very hard to measure. This is the first study that has been able to really measure it in a coherent way," said Sally McGill, Professor of Geology and California State University, San Bernardino.

Part of the earth is rising, while other parts are sinking.

"For the southernmost part of the San Andreas, the land to the east is going up, and the land to the west is going down," said McGill.

That’s the opposite of what’s happening up north where the fault continues north of us for 800 miles.

Scientists say this study is another piece of the puzzle to learn about the earthquake process.

Despite this new information, they still can’t predict when the big one will hit. 

"The San Andreas Fault has had major earthquakes in the past, and will again in the future, the exact timing of those earthquakes though is something that’s just not attainable right now," said Graves.

According to scientists, the last major earthquake along the section of the San Andreas that runs through here from San Bernardino and Imperial Counties was about 300 years ago.