California is Earthquake Country
With record price drops over the last year, the California Real Estate market may seem a little shaky, but California Real Estate is ALWAYS shaky, because we live in earthquake country. Californians are industrious, enterprising people, so we take this fact of life in stride. Increasingly strict standards for design and construction within the state are intended to minimize the structural damage and loss of life caused by earthquakes, but each resident must be prepared.
Just how seismically active is California? The U.S. Geological Survey maintains Earthquake Information and Hazard Maps on their websites. You can see last week’s seismic activity for the entire nation on this page. While there’s always lots of activity, the low maginitude rumblings are seldom noticeable to residents. Magnitudes in the mid 5’s and above will generally produce significant damage, depending on their location. Significant California area quakes from 1769 to the present are shown on this page.
Earthquakes in San Diego County
Luckily for most areas of San Diego county, the frequency and intensity of damage-producing earthquakes is less than in many California counties. (Read more on this webpage, and view the map showing frequencies of damaging quakes in Southern CA.) While this is a comforting fact, there is no way to predict where or when the next major quake might occur, so all California residents must be prepared for a possible earthquake, no matter where they live.
The last strong earthquake which did damage to San Diego was on May 27, 1862. It was estimated to have a magnitude of 6.0, and damaged Old Town and the San Diego River mouth area. The strongest recorded quake in coastal San Diego County had a magnitude of 5.3, occurred July 13, 1986, and was located 25 miles off the shores of Solana Beach. It is likely that San Diego County will experience one or two damaging quake per century. You can read more about San Diego Faults and Earthquake Activity on the San Diego Museum of Natural History’s website.
The City of San Diego Seismic Safety Study was updated in 2008, and beautifully detailed maps are available online. The maps show known faults, fault zones, and areas with known soil instabilities. If you live in San Diego, you can see how close your home is to the nearest faults or unstable slopes. If you are looking for a home, you might want to consult this map before you fall in love with a neighborhood.
How Shaky is your Home?
The ability of a home to withstand earthquake damage depends upon many factors. Building codes have been strengthened to make homes safer from the shaking of earthquakes, so homes built after 1960 are less susceptible to earthquake damage. Homes built before 1960 can be strengthened, and there are many references which can help you to identify potential weak points in a home. In many cases, needed repairs are relatively economical.
There are many references available to help residents of California prepare themselves, their families, their belongings, and their homes for an earthquake. Links to many helpful webpages are listed below in the references section. My favorite reference booklets are the following:
My Favorite Earthquake References:
- Putting Down Roots in Earthquake Country:
- This 32 page booklet is the great resource. The booklet is a wonderful overview of almost everything you might want to know about earthquakes in CA. The booklet covers what they are, why they happen, where they occur, how to be prepared, spotting and eliminating structural weaknesses in your home, and what to do after an earthquake.
- The Homeowners Guide to Earthquake Safety
- This 53 page booklet is required reading when buying OR selling a pre-1960 home in California. Published and maintained by the Seismic Safety Commission, this is a must read booklet for owners, potential buyers and also renters of pre-1960 homes. The booklet identifies the following structural weaknesses which may be found in pre-1960 homes, and also explains how to correct them.
• Homes not Anchored to Foundations
• Unbraced Cripple Walls
• Pier and Post Foundations:
• Unreinforced Masonry Foundations
• Homes built on Steep Hillsides
• Unreinforced Masonry Walls
• Rooms over Garages
• Unreinforced Masonry Chimneys
• No Foundation or Old Concrete Foundations
• Homes with Unusual or Unique Designs
Every pre-1960’s home is different, and some will have few of the items on this list. However, it is important to be aware of weaknesses in your current residence, or in on that you are interested in purchasing.
Buying and Selling pre-1960 Homes
The state of California requires sellers of residential homes (1-4 unit properties) to complete the following earthquake related items:
- disclose known home weaknesses
- strap water heaters
- provide a Natural Hazards Disclosure (discloses Earthquake Fault Zones or Seismic Hazard Zones)
These items are also required if the home was built prior to 1960:
- The Homeowners Guide to Earthquake Safety
- Residential Earthquake Hazards Report (This disclosure: can be found on page 47 in the Homeowners Guide to Earthquake Safety)
Home sellers and buyers are NOT required have homes inspected for hazards OR to strengthen homes, but are advised that many of these repairs are economical compared to the costs of repairing earthquake damage. Also, it’s good to know that seismic strengthening does NOT trigger a property tax reassessment IF the proper forms and procedures are followed. Be sure that either you or your contractor obtains this information when obtaining permits.
It is very important for home buyers to realize that earthquake insurance is usually NOT part of your homeowner insurance policy. Earthquake insurance may be purchased separately and cost depends on the deductable, and the home’s location, construction, age, and value. Consider the cost of the expected damage versus the deductible on the policy.
References:
- www.earthquakecountry.info
- www.daretoprepare.org
- San Diego County Disaster Preparedness Earthquake Page
- www.shakeout.org
- www.terremotos.org (Earthquake Information in Spanish)
- US Geological Survey Earthquake Information Page
Tags: Earthquake hazards in San Diego county, Earthquake Safety in CA Homes, San Diego Real Estate and Earthquakes