January 26, 1700, approximately 9 p.m. — the earth ruptures, coming unzipped along 600 miles of coastline from what is now British Columbia into what is now northern California.

The whole world shakes, and it seems like it will never end. Massive sections of forested coastline nearly instantly drop three to six feet, leaving giant trees embedded in salt water to die and leave ghost forests that will stand sentinel in the sand three centuries later.

A tsunami will roll across the ocean, taking nine hours to reach Japan. Scribes will leave record of this “orphan tsunami” that arrived from thousands of miles across the ocean without anyone in Japan feeling the quake that heralded it.

The quake must have been a magnitude 9 — one of the most powerful in history.

It will happen again. It could happen at any time. Scientists estimate that there is a one-in-three chance of a megaquake hitting in the next 50 years.

The potentially catastrophic effects of a “full rip” Cascadia Subduction Zone earthquake are highlighted in the Great Oregon Shakeout, part of the International ShakeOut Day (always the third Thursday of October).

The effects, as can be imagined, would be catastrophic on the coast, with massive damage from the shaking and from a likely tsunami, which would probably inundate many low-lying areas.

Effects would be felt far inland, with significant damage in the Willamette Valley. Depending on the time of year, a megaquake could trigger multiple major landslides that could cut off highways through the Coast Range and the Cascades.

And many of the state’s highway bridges would be rendered unusable — either heavily damaged or collapsed.

For Central Oregon, it is this disruption of transportation and the ripple effects of damage elsewhere that will be the most significant effect of a full-scale Cascadia Subduction Zone earthquake.

Direct damage from shaking is likely to be minor. But the people of Sisters Country are not insulated from the effects.

“All of the things we take for granted will be impacted for a significant period of time,” said Jack McGowan, a long-time preparedness advocate who serves on the Sisters-Camp Sherman Fire District Board of Directors.

That includes groceries and fuel supplies, and power may be cut off.

If the quake happens in the middle of winter, as the 1700 quake did, that could leave many local residents without their main source of heat. And electrical power is vital to keeping water supplies flowing, too.

The Sisters-Camp Sherman Fire Department is encouraging local residents to participate in the Great Oregon Shakeout drill, set for October 15. Visit www.shakeout.org/oregon/ for information.

But McGowan notes that the Great Oregon Shakeout for Sisters isn’t so much about the shaking as it is being prepared for the after-effects of the shaking.

Self-reliance will be critical to get through the immediate and long-term aftermath of a megaquake. Emergency responders will be busy, even if they are not sent to other parts of the state to help quake victims.

What can local citizens do to be prepared for a major emergency such as a catastrophic mega earthquake?

First, recognize the vulnerabilities. In a “full-rip” Cascadia Subduction Zone earthquake, there is likely to be significant damage to the state’s major fuel depot in the St. Johns area of Portland. And re-routing fuel supplies, which are contracted for, won’t be a quick or easy proposition. And in a major region-wide emergency, fuel will be allocated first to emergency responders.

Fill your tank — and don’t let it get below half-empty. That way you’ve always got at least some fuel on hand. A couple of safely stored five-gallon gas cans are a good idea, too — treated so that the fuel doesn’t go bad. Drop the gas into your tank every few months and get a fresh supply in the cans.

Water is critical to life. Experts recommend storing at least one gallon of water per person for three days for drinking, cooking and sanitation. (www.ready.gov/water). That’s a lot of water in an emergency that lasts for several days or weeks.

Putting up a few flats of commercial bottled water is a good idea, as is filling several camping containers. It’s also a very good idea to have a good water purification device in case you are caught somewhere away from your water supply. It’s always a good idea to carry one in your hiking pack or your emergency car kit anyway.

The grocery supply network is likely to be severely disrupted in a major earthquake scenario. Most emergency plans call for food supplies for 72 hours — but for an event like a Cascadia quake, you need to be prepared for much longer: Three weeks to a month.

Don’t count on the ability to refrigerate food. And don’t forget that your pets will need to eat, too — so you need to lay in a backup supply of their food as well.

You’ll also need to have the means to cook. Camping stoves are convenient, easy to use and effective.

It’s a very good idea to have an emergency backup for vital medications. Just like the food chain, the supply chain for pharmacies is likely to be disrupted.

Having an alternative source of heat is important if you heat primarily with electricity. A portable gas-powered generator is fine for a while — but in a scenario where fuel supplies are short for an extended period of time, that may not help you.

A wood stove requires nothing but some muscle to create the fuel.

Get a Red Cross solar/crank radio so you won’t be completely out of touch on vital announcements/news if the communication net goes down for an extended period.

For some folks, there is an innate, perhaps subconscious, resistance to spending money and effort preparing for something that may never happen. But preparing for “The Big One” also leaves you in great shape to handle smaller emergencies, from winter power outages to a financial crunch that forces you to tap some emergency supplies.

And, for the well-prepared, the confidence that you are ready for anything and in a position to help your family, friends, and neighbors, offers tremendous peace of mind.