The following story originally appeared in the Alki News Beacon in 2002, says writer John Sheirbon, but he asked if we’d be interested in sharing it with you – we didn’t see it first time around and maybe you didn’t either.

(another great aerial photo by Gatewood pilot Long Nguyen – Alki Point at upper right)
By John Sheirbon
Special to West Seattle Blog

Between 900 and 930 AD, the Puget Sound region was shaken by a strong earthquake (of at least magnitude 7) along what is now called the Seattle Fault. While researching this piece, I wondered what it might have been like to experience the event. Herewith, a yarn:

It was an early spring day, unseasonably warm, and perfect for the wedding. Seiahaluch, a young Suquamish lad, and his betrothed, Tsetsequis, of the Duwamish Tribe, were eager for their marriage ceremony to end so that they could escape to their honeymoon retreat.

Two or three minutes later the shaking faded, and the thunderous sounds of a contorting Earth’s surface were supplanted by the rush of water still draining off of the newborn platform. The newlyweds stood silently in awe, surveying the unimaginable change that has just transpired. They found themselves standing no longer on an island, but a hill, on a point of land – what’s now known as Alki Point.

****

What the newlyweds didn’t know was that, concurrently, the earthquake was causing huge avalanches on the Olympic Peninsula that would block three streams to create Jefferson, Spider, and Lower Dry Bed Lakes. Near Kirkland, and on the southeast end and west side of Mercer Island, four nearly simultaneous massive block-landslides of forested land, with trees still upright, were being deposited into Lake Washington. One thousand years later, in 1919, one hundred eighty-six of these trees were removed as hazards to navigation.

The shadows that Tsetsequis saw were 15-foot-high tsunamis formed by the displacement of the seafloor along the Seattle Fault. Two or three more such pairs of “harbor waves” would occur 10 to 20 minutes apart, any of which could be the largest. All reached speeds of about 80 mph or higher in the central sound. One deposited a Douglas Fir tree on the beach at West Point (which had just subsided 3 feet) and was discovered in the early ’90s during a construction dig. That tree’s rings were used to determine, with relative accuracy, the year of the quake.

I’ve taken historical license with the love story in this piece, but there were native inhabitants populating the area at the time. The earthquake and tsunami, and their effects on the landform are fact. If you take the Bremerton or Bainbridge ferries, you’ll have a good vantage point from which to view clear evidence of the event. At Restoration Point can be seen a large, raised platform of nearly planar bedrock standing over 20 feet above the current high tide line, upon which a golf course now sits. This terrain was thrust upward out of the water during the earthquake.

Scientists had thought that such an uplift might have occurred at Alki Point as well. But they didn’t have proof until Paul Bierman happened to stop at Alki for lunch one day in 1991. A graduate student in geology at UW, Paul took an academic interest in foundation work being done for a new condo on Beach Drive, not far from the lighthouse. After taking a look at the exposed strata, he informed mentors of this cursory survey. Further investigation confirmed their suspicions.

The uplift at the Point was greater than 13 feet, but by just how much isn’t yet known because evidence has been obscured by development. This is where you may be able to help. Imagine a triangle with corners roughly at Alki Ave. SW @ 55th, the lighthouse, and SW Spokane St. @ Beach Drive SW; if you know of any excavations, such as sewer or foundation work that are being, or will be done anywhere in this area, geologists would like to hear from you. They are interested in digs of at least five feet deep. This sort of “budget” geology may offer them a chance to fill gaps in their knowledge.

The destructive potential of future displacements of the Seattle Fault must not be ignored. The earthquake 1100 years ago produced an uplift of at least 20 feet on the south side of the fault, and a subsidence of at least 3 feet on the north. That’s a minimum of twenty-three feet change in elevation between Restoration Point and Magnolia in about three minutes. A magnitude 7 quake on the Seattle Fault could easily exceed the damage to our immediate area than that caused by a magnitude 8 “great” quake on the Cascadia Fault off our coast.

A tsunami in the Elliott Bay area will beach at about 15-20 mph, which may not seem fast, but if you hang around to watch it, you might not be able to outrun it-quickly beat feet to high ground if you feel strong shaking. It wouldn’t be another “Indonesian tsunami,” but it could still kill you.

And where exactly was Meditation Island? There’s good reason to believe that, before the quake, the hill behind the Alki Point Lighthouse was an island – peer up Benton Pl. SW from Beach Drive (map), or from the other side, it’s the hill at the west end of Admiral Way.

Thanks to Brian Atwater of the U.S. Geological Survey and Frank Gonzalez of NOAA for their infinite patience and allowing me to pick their brains.

Editor’s note: If the names of John’s fictional couple sound familiar – more than a century ago (but almost a millennium after the quake), a Salish couple with those names were photographed, and it’s in the historical archives.