Earthquake

Earthquake is ranked among the highest risk hazards to impact Cupertino. An earthquake is the vibration of the earth’s surface following a release of energy in the earth’s crust. This energy can be generated by a sudden dislocation of the crust or by a volcanic eruption. Most destructive quakes are caused by dislocations of the crust. The crust may first bend and then, when the stress exceeds the strength of the rocks, break and snap to a new position. In the process of breaking, vibrations called “seismic waves” are generated. These waves travel outward from the source of the earthquake at varying speeds.

Earthquakes can last from a few seconds to over five minutes; they may also occur as a series of tremors over a period of several days. Aftershocks may be felt for months or years after the mainshock. The actual movement of the ground in an earthquake is seldom the direct cause of injury or death. People that fall over during the quake may experience more mild injuries like broken bones. Casualties generally result from falling objects and debris, because earthquakes shake, damage, or demolish furnishings and buildings and other structures. Disruption of communications and internet, electrical power, gas, sewer, and water services should be expected in the affected area. Earthquakes may trigger dam failures and landslides. Their damage may cause fires and releases of hazardous material, compounding the disastrous effects.

What can you do? Prepare for Earthquakes

Earthquake Ready in 4 Steps

Sign up for AlertSCC at www.AlertSCC.org
Make a plan
Build an emergency supply kit
Help your community

Read on for preparedness tips BEFORE , DURING, and AFTER an EARTHQUAKE

Before an Earthquake

We can prepare now by ensuring that our homes are earthquake ready. No-cost actions we can take include moving heavy objects from top shelves down to the lower shelves or floor and not hanging heavy objects over our beds and sofas. Low-cost actions include securing our cabinets and drawers, adding safety latches to keep cups and dishes from falling out, and securely fastening large appliances and furniture to wall studs or bolting them down.

Steps we can take to be earthquake ready:

Securing our space by identifying hazards and securing moveable items such as furniture and other heavy objects to avoid injuries and damage.
Planning to be safe by creating a disaster plan and deciding how you will communicate in an emergency. Where will you meet your family? How will you get to work? Do you know how to perform CPR or use a fire extinguisher?
Organizing disaster supplies by packing our Go Bags, an emergency supply kit for when we are required to evacuate immediately.
Minimizing financial hardship by organizing important documents, strengthening our property, and considering insurance.
Practicing Drop, Cover, and Hold On so that we know what to do when an earthquake strikes.
Improving safety after earthquakes by evacuating, helping the injured if possible, and being ready for aftershocks.
Reconnecting and restoring by checking in with family, friends, and neighbors, repairing damage, and rebuilding your community.

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During an Earthquake

When the ground starts shaking, immediately drop to the ground - cover your head and shoulders with your hands, crawl under a sturdy desk or table, and hold on until the shaking stops - remember, DROP, COVER and HOLD ON! If no sturdy shelter is nearby, crawl away from windows next to an interior wall. Stay away from glass, windows, outside doors and walls, and anything that could fall, such as light fixtures or furniture.

Stay where you are until the shaking stops. Do not run outside. Do not get in a doorway, as this does not provide protection from falling or flying objects, and you may be unable to remain standing. If you are in bed: Stay there and cover your head and neck with a pillow. At night, hazards and debris are difficult to see and avoid; attempts to move in the dark result in more injuries than remaining in bed.

After an Earthquake

Be prepared to DROP, COVER and HOLD ON for aftershocks.

The moment the ground stops shaking, it is important to act quickly and safely. Look around to identify any new hazards such as leaking gas lines, damage to the building, downed water or electric lines, or other things that may be dangerous. Always remember that your safety comes first! When you are safe, you will be better positioned to help others.

Put out any small fires you see in your home with a fire extinguisher.
Shut off the main gas valve, and do not use candles or matches if you suspect a gas leak.
Shut off power at the main breaker and leave it off until repaired.
Unplug any broken lights or appliances as they could cause fires when power is restored.
Consider all downed power lines as LIVE and stay clear. Do not touch with your hands or other objects.
Open cabinets and cupboards slowly as items may have shifted.
Use extreme caution cleaning up any spilled medicines, drugs, or other non-toxic substances. Potentially harmful materials such as bleach, lye, garden chemicals, gasoline, or other petroleum products should be isolated or covered with an absorbent such as dirt or cat litter. When in doubt, leave your home.
Check for damaged masonry, such as chimneys and walls made of brick or cement blocks.

Earthquake Resources

Get earthquake warnings before an earthquake by downloading the MyShake App.

Look for hazards in your area with the Cal OES MyHazards Tool.

Find where the latest earthquakes occurred by visiting U.S. Geological Survey.

Earthquake resources and information from Ready.gov/earthquakes.

Participate in the Great California ShakeOut earthquake drill.

Join the Earthquake Country Alliance.

Learn more about the services provided by the American Red Cross.

Get earthquake insurance provided by the California Earthquake Authority.

What is the City doing? City Actions

The City of Cupertino works to mitigate the impact of earthquakes through mitigation, preparedness, response and recovery efforts.

MITIGATION

Infrastructural maintenance and upgrades, summarized in the City Work Program, target seismic retrofits, evacuation route hardening, and other projects aimed at shoring up infrastructural vulnerabilities in a catastrophic event.

PREPAREDNESS

The City offers personal and family emergency preparedness training to residents throughout the year. The Public Safety Forum, hosted for the City each October, provides residents an array of public safety and preparedness resources to use before or during an event like an earthquake. Visit the City Calendar to view and register for these, and other public safety events.

RESPONSE

The City coordinates with special districts and non-governmental organizations like the American Red Cross to prepare to staff shelters in the event of an emergency where people are displaced. In 2023 the Red Cross and the City Office of Emergency Management collaborated on training City staff to support care and sheltering operations.

The City Office of Emergency Management develops and maintains the Emergency Operations Plan, Continuity of Operations Plan, and Multijurisdictional Hazard Mitigation Plan. Learn more about these plans, and the role they play guiding emergency management on our Plans page. Provide feedback on plan development and maintenance.

RECOVERY

Recovery after a catastrophic earthquake can take years. The City is prepared to support the community throughout the process, connecting residents with local, state, and federal resources when they are available.

There are 16,413 buildings with vulnerability to earthquake (with estimated value of structure and contents $13,890,786,985). Based on property loss estimates conducted through the Level 2 Hazus analysis for the 100-year and 500-year earthquakes, Cupertino total losses range from about $623 million to about $2 billion. Of the three earthquake fault scenarios considered for Santa Clara County, Cupertino is most vulnerable to an earthquake along the San Andreas Fault.