Earthquakes strike without warning. Surviving the Big One might depend on how well prepared you are.
Washington state just released “A Homeowner’s Guide to Earthquakes in Washington State” to teach citizens how to prepare for quakes and protect their property.
The 28-page online booklet, produced by the Washington Geological Survey, also has a lot of facts:
▪ Quakes come in three types: Subduction zone, deep and shallow.
▪ The first Washington state building codes for earthquake safety were adopted in 1975.
▪ The last Big One to hit Washington was in 1700.
That 1700 quake was a Cascadia Subduction Zone quake and thought to be near the same magnitude (9.0) as the 2011 Tohoku earthquake off the coast of Japan. While those quakes strike off the coast and inevitably bring tsunamis with them, quakes also strike Puget Sound and eastern Washington.
The 2001 Nisqually Earthquake had a magnitude of 6.8, caused serious damage from Olympia to Seattle and injured hundreds of people.
Helpful for homeowners, the new booklet identifies and explains various building features that could be hazardous in a quake. It’s not, the booklet makes clear, a how-to guide.
Wood framed buildings can twist in a quake but survive. Unreinforced masonry is more unforgiving and more likely to collapse.
Among other home improvements, the booklet advises:
▪ Anchor decks to houses.
▪ Secure propane tanks and water heaters.
▪ Attach wood stoves and flues to floors and ceilings.
▪ Reinforce items in the house that could fall on children or vulnerable adults, such as televisions, large furniture and even small but dangerous objects.
It’s not just what your home is made of but where it’s sited that makes a difference when it comes to damage. The 1989 San Francisco Bay Area quake provided ample evidence that different types of soils in the same vicinity can react differently in an earthquake.
Along with surface ruptures and shaking, other earthquake-induced hazards include landslides, liquefaction and tsunamis.
Although Washington’s Pacific Ocean coastline remains the most vulnerable in a Cascadia Subduction Zone quake, Puget Sound is not immune to tsunamis. Even a Puget Sound quake can cause a tsunami, the booklet points out.
Many century-old homes in western Washington today have newer chimneys — the result of the 1949 earthquake that destroyed period brickwork. The booklet offers tips on checking the safety of your chimney.
Like any good earthquake-safety manual, the booklet has a checklist of more than 20 items to have on hand for a post-earthquake survival kit. Along with food, clothing and first aid, some not-so-obvious items include sleeping bags and a tent, important documents and food for pets.
The booklet can be found at: dnr.wa.gov/publications/ger_homeowners_guide_earthquakes.pdf.