How will a 7.3 Earthquake on the Hayward Fault or a 6.9 Earthquake on the Calaveras Fault Impact Pleasanton?

An earthquake with a magnitude of 7.3 (M7.3) on the Hayward Fault or a magnitude of 6.9 (M6.9) on the Calaveras fault may result in widespread destruction not only in Pleasanton but in the nearby communities as well. 

Those nearby communities, Dublin, Livermore, Castro Valley and Sunol will be impacted with nearly the same destruction as may occur in Pleasanton. For this article I have addressed the impact on Pleasanton. Readers in nearby Patch communities are encouraged to comment on this article.

I initially contacted Pleasanton City Manager Nelson Fialho twice by email with questions for this article. The first email apparently was forwarded to James Miguel, Pleasanton Livermore Fire Chief. James Miquel forwarded that email to the Disaster Preparedness Manager. The second email went unanswered also.

With none of the three people responding back to me, I went to the experts in Menlo Park at the United States Geological Survey to get my questions answered. They provided immediate response to my questions.

I remain disappointed with the Pleasanton City Manager, the Pleasanton-Livermore Fire Chief and the Pleasanton Disaster Preparedness Manager.

They had my questions for fourteen days and never responded.

Every family should have a plan worked out as to what actions each family member should take in the event of a major earthquake. Those individual plans should factor in multiple scenarios.

If the earthquake happens when you are at home, at work, at school, shopping or driving, every family should have a plan with individual responsibilities for getting safely reunited as soon as is possible.

For our family, our plan is simple. Our plan is to go home. If you are at home, stay home. If the home is not safe to occupy, remain in the yard of your property until all family members have safely returned home.

While waiting for family members to get home, assess your situation. Your home is demolished, get out your earthquake emergency supplies kit if it can be retrieved safely. Salvage what you can from the home to set up camp in your yard.

It may take several hours for some family members to get home. Cell phones may not work, land lines may not work, driving may be impossible. Turn on the portable battery-powered radio you have stored in your earthquake emergency supplies kit.

The good news for Pleasanton is that the USGS thinks the largest earthquake possible on the Hayward Fault is a M7.3 and on the Calaveras Fault is a M6.9. An earthquake on the Calaveras Fault will shake Pleasanton much more violently than an earthquake on the Hayward Fault.

Did you know that the Calaveras fault runs along Foothill Road in Pleasanton? Yes, nearly right under my home and a lot of other homes in Pleasanton. An M6.9 earthquake on the Calaveras may take out all access into and out of this area.

The only way into this immediate neighborhood is across the Sunol Castlewood bridge, Calaveras and Niles Canyon Roads from the south, the Bernal Bridge, the West Las Positas overpass bridge, the Stoneridge overpass bridge, and the Stoneridge hill from the west or I-580 Foothill Road exit and overpass bridge. There are a couple of smaller county roads from the south and west.

Probabilities are Pleasanton may be impacted with widespread destruction. Some freeway overpasses on I-580 and I-680 may have collapsed. Water mains may be severed. Water pump stations may go down. Sanitary sewer system lines may be severed. Sanitary lift stations may go down.

Police and fire departments will be overwhelmed. Emergency City Government personnel will be unable to get to the emergency command center. It may be several hours before the emergency command center is operational.

There may be hazardous chemicals released in a M6.9 on the Calaveras Fault. There may be earthen dam failures. Motorists may be stranded on the freeways. There may be toxic smoke from fires that may burn for days. There may be no water to fight the fires.

There may be deaths and there may be injuries. Jack Boatwright of the USGS said "it is very difficult to predict fatalities. Because building stock in suburban areas is relatively strong (1&2-story wood frame homes), the number of fatalities from local earthquakes can be extremely quirky and unpredictable."

USGS provided the following link:

http://www.cisn.org/shakeemap/nc/shake/archives/scenario.html

Click on the Central Calaveras + Northern Calaveras (CC+CN).

The color coding on this shake map indicates severe to violent shaking for Pleasanton in a M6.9 Calaveras earthquake. Also visit the USGS site:

http://www.earthquake.usgs.gov/

The bottom line for all of us is to be  prepared with a family plan. Double check your earthquake emergency supplies kit. Replace batteries every six months to a year to keep them fresh and fully charged.

Do not rely on government services for any relief. We all will have to rely on our own strengths and resources for several days. Remain together so that when help does become available, your family will be evacuated together.

I originally downloaded City of Pleasanton ANNEX D - All Hazard Vulnerability Assessment at:

http://www.ci.pleasanton.ca.us/pdf/annex-d.pdf

And here is the city's emergency preparedness plan:

http://www.ci.pleasanton.ca.us/services/fire/emergency-preparedness.html

It is a 72-page document and generalizes on hazards from chemical releases, floods, fires and earthquakes, does not give specifics. The earthquake maps quality are not as good as the USGS maps quality.