A tsunami with waves up to 8 feet high could inundate Quartermaster Harbor just 18 minutes after an earthquake on the Seattle Fault, potentially immersing homes, beaches, people and animals at 15 feet of elevation and below.

This message — that Vashon is vulnerable to a fast-moving tsunami following an earthquake — is one of the disaster-related issues two state experts will discuss at the annual meeting of VashonBePrepared next week. In recent years, scientists have learned a great deal more about the risk to the Puget Sound region from both earthquakes and tsunamis. At the presentation, John Schelling, the earthquake program manager for the Washington State Emergency Management Division, and Tim Walsh, the chief hazard geologist at the Washington Geological Survey, will discuss the latest findings and provide information to Islanders about how they can best be prepared.

“One of the things we want people to take away … is the fact that we want them to be the survivor story,” Schelling said recently.

Earthquakes are a fact of life in the Puget Sound region, and preparedness is important, he stressed.

“What you do today will determine how fast you and your family recover afterward,” he said.

Earthquakes and the resulting tsunamis in Samoa in 2009, Chile in 2010 and Japan in 2011 have contributed to new understandings about both events, Schelling said. In his presentation, he will focus on how people can best be prepared while Walsh will discuss the latest research and what the most recent findings might mean for Vashon. Walsh also plans to share animation that illustrates just how quickly a tsunami could inundate the low-lying areas of the Port of Tacoma and Fife. Six to 15 feet of water would be expected there within minutes of a quake; the scientific modeling for that project included parts of Vashon, he said, and will help residents understand potential tsunami scenarios for Vashon more clearly.

If one occurs here, residents need to be prepared not just for water, he said, but for the debris that comes with it, including — potentially — the contents of log yards near low-lying ports  and houses that have been knocked off their foundations and carried away.

Such debris could present considerable difficulty, including creating an additional impediment to ferry travel to and from the mainland. If a whole house floated on to a ferry dock, he noted, it would need to be removed before travel could resume.

To best withstand such a disaster, Schelling said that understanding potential scenarios and knowing the right action to take is vital.

Standard earthquake advice used to be “drop, cover and hold,” he said, but now, for people living near a shore, the directive is to “drop, cover, hold and then go to higher ground as quickly as possible.”

“The response by citizens has to be automatic,” Walsh said.

Schelling stressed the importance of practice for such an event. When the people of Crescent City, Calif.,  had to evacuate following last year’s earthquake in Japan, many said it felt just like a drill, he noted. Drills had been helpful in Japan as well, where, despite widespread tragedy,  having practiced for a tsunami saved many people’s lives.

On Vashon, as in many other communities in Washington, Schelling encourages organizations, neighbors and communities to take action, train themselves about tsunamis and take ownership of how they will respond if necessary.

“It offers peace of mind,” he said.

He also noted that Washington has three coasts: the outer coast, the coasts of the Strait of Juan de Fuca and the coasts of Puget Sound.

“Each has unique hazards,” he said.

Such an event is entirely possible, he noted: For this region, there is a 5 percent chance in a 50-year period that a tsunami will strike.

In addition to discussing the more recent understandings of tsunamis, Schelling will discuss how to best be prepared to withstand the effects of a major earthquake, including low or no-cost steps people can take to secure their home and work spaces: anchoring bookshelves, strapping a hot water heater water to the wall and securing a flat screen TV, for example.

“It’s an hour project,” Schelling said about securing the TV. “It might seem trivializing. But if somebody is in that room, it’s going to save their lives.”

Both men note they are aware that earthquake fatigue sometimes sets in and people can grow tired of hearing about the possibilities that might befall this area.

Walsh countered by pointing to recent history: The last earthquakes in this region higher than a 6.5 were in 1949, 1965 and 2001.

“Eye rolling is not a good idea,” he said. “If you grow up here, you can expect two to three large, damaging earthquakes in your lifetime.”

The presentation and general meeting of VashonBePrepared will be from  7 to 9  p.m. Wednesday, April 18, at Chautauqua Elementary School. Sen. Sharon Nelson and Fire Chief Hank Lipe will host the event. For more information, see www.vashonbeprepared.org.

Great Washington Shakeout: Get set for the big one

The Great Washington Shakeout, in which thousands of people throughout this state and beyond will participate in an earthquake drill, is set for 10:18 a.m. Thursday, Oct. 18.

Simultaneously, participants will drop, cover and hold on, as part of the drill. John Schelling of the Washington Emergency Management Division said organizers hope that 1 million Washingtonians will participate — and then complete one additional preparedness task.

California, Oregon and British Columbia are all participating in this exercise at the same time, Schelling said.

To register to participate and for more information, see www.shakeout.org/washington/.