It only takes a few dips of a paddle into the Copalis River and a scan of the bank to find activity. A heron glides on gargantuan wings. A kingfisher cackles and darts between spruce trees. A family of river otters tucks behind a log nestled on the muddy bank. A fisherman flings his lure into the foamy surface.
Signs of life are everywhere. The signs of death are perhaps more alluring.
A few more dips of the paddle brings into view a span of limbless trunks and stumps poking up from the marsh. They are pale, frayed and dead, and have been for 300 years. This “ghost forest” is named as such.
A plod through the ghost forest produces wet feet, showing why: the ground is soaked in saltwater. The trees died when the toxic water choked their roots.
That was never the mystery here. What was, and what put this forest on an international scientific radar more than three decades ago, was how it happened.
A perfect match
Anyone who stumbled upon the rot-resistant red cedar ghost forests of the West Coast prior to the 1980s could have reasonably assumed that anything other than a tsunami killed the trees in the tidal marsh. When naturalist James Graham Cooper wintered at Willapa Bay in the 1850s, he guessed the trees had died by sliding into tidal quicksand. Later, others assumed rising sea levels slowly crept up and killed the trees.
When Brian Atwater, a geologist with the United States Geological Survey, went to the forest in the 1980s, he thought and found otherwise, and it was his work, along with a team of dedicated scientists, that led to an important discovery about the death of the trees.
It occurred much more rapidly than previously thought.
The ghost forest is the result of the last major earthquake of the Cascadia Subduction Zone that occurred more than 300 years ago, which caused the land where the coastal forest grew to drop by six feet, plunking the trees into the tide.
“It’s a very, very fast sort of death, if you want to think of it that way,” said Alex Dolcimascolo, a tsunami geologist with the Washington Geological Survey and the Department of Natural Resources.
Not much has changed since Atwater’s discovery in terms of new information about the ghost forest, Dolcimascolo said, but the forest remains one of the only tangible tools for explaining tsunami behavior — and what that means for hazard preparedness — to the public.
It’s the place that “brings it all together,” he said. “The Copalis River is direct evidence our lands once faced this massive event.”
The seismic events produced by the Cascadia Subduction Zone, and other “megathrust” faults, are the largest in the world. No more than 100 miles from the Northern Pacific coast, the Pacific oceanic tectonic plate is slowly subducting under the North American continent. When friction gives way and the plate slips, it shakes the earth violently — possibly a magnitude 8.0-9.0 or greater — and sends a tsunami to shore, inundating coastal areas.
Geologists knew about megathrust faults and the earthquakes they produce prior to Atwater’s discovery. There were already ample written records that a massive tsunami of this type hit Japan 300 years ago, but it was unclear what had caused the wave — the “orphan tsunami” — to rush onshore.
When Atwater and company began to piece together evidence at the ghost forest, it became clear they had found the Japanese orphan tsunami’s parent. Atwater teamed up with David Yamaguchi, a dendrochronologist (tree ring scientist), who traveled to Copalis and took a slice from one of the trees. Its rings show the tree was healthy until the time of its death, no sign of gradual suffering or disease. Radiocarbon dating pinned the date of death somewhere between 1690 and 1710, and a slew of other samples indicated the trees had their final growing season during the summer of 1699, and were dead by the following summer.
That matched Japanese records of an estimated 9.0 earthquake there. The date was January 26, 1700.
Atwater and Yamaguchi published their findings in scientific papers, and with four other authors compiled evidence in the book “The Orphan Tsunami of 1700: Japanese Clues to a Parent Earthquake in North America.”
The evidence for activity at Cascadia — and that coastal land had dropped, specifically — went further than trees. Like a geologic layer cake, evidence is displayed in deposits of material on the banks of the Copalis. Cutting into that cake, scientists found layers of forest floor buried and preserved beneath tidal deposits and the modern salt marsh.
Digging deeper, they found the story told by the ghost forest went back further than 1700. Across the coast, fossils of delicate vegetation hundreds of years old were preserved when tidal mud covered them following a subduction zone earthquake. Hearths, fishing weirs and other artifacts wedged within the layers are evidence of the people who inhabited the coast during the last Cascadia events.
Between layers of forest floor and tidal muds are thin layers of white sand, brought from the ocean by a surging wave. Measuring the distance between the sand layers is a good way to estimate the interval at which Cascadia earthquakes have occurred, Dolcimascolo said. The layers indicate six major earthquakes in the last 3,500 years, with intervals of 400-600 years, on average.
That interval isn’t always constant.
“We believe there’s individual intervals from earthquakes that can vary between 100 years up to maybe as long as 1,300 years,” Dolcimascolo said, citing a study by Atwater and Eileen Hemphill-Haley from the 1990s.
In between earthquakes, coastal land rises slowly. When the ocean plate dips beneath the continent, the coast begins to curl with friction, lifting the ghost forest with it. Dolcimascolo demonstrated the phenomenon by sliding one hand underneath the other, his knuckles lifting.
“As that’s being pushed and pulled underneath the land, you kind of have a bulge effect,” he said.
When the fault slips, the end of the continental plate, out at sea, flips up like a spring board, causing the giant wave, while coastal land falls — a phenomenon called subsidence. In addition to rapidly altering forest ecosystems by dropping them into the tide, subsidence will allow tsunami waves to travel farther onto land than they would otherwise, Dolcimascolo said.
“With the tides coming in and flooding the land twice a day, that’s pretty significant for the land and it’s potentially what we could see in the next Cascadia Subduction Zone event,” he said.
Many oral traditions of native people from Vancouver to Northern California carry stories of the struggle between Thunderbird and the Whale, which commonly contain earthquake and tsunami imagery.
In “The Orphan Tsunami,” authors cite a Yurok myth recorded 100 years ago as a clue to the sudden change in environment that occurs after a Cascadia event: “Thunder wants people to have enough to eat. He thinks they will if prairies can be made into ocean. He asks Earthquake for help. Earthquake runs about, land sinks, and prairies become ocean teeming with salmon, seals, and whales.”
Sharing the story
When Atwater returned to the Copalis River in the decades following his discovery to teach students or provide information, he sometimes ran into Buck Giles on the river.
Giles is the owner of Buck’s Northwest, an outdoor adventure store in Seabrook. For the last six years the store’s arsenal of offerings has included guided tours of the Copalis ghost forest. Since then he’s also become the go-to guy for getting to the forest: a string of media outlets from across the world on filming expeditions have called on him for guidance, most recently National Geographic in its production of the documentary series “Drain the Oceans.”
Born and raised on Grays Harbor, Giles said much of his motive to provide ghost forest tours was “spurred from the desire to show people my backyard,” he said.
And he’s told the story of the ghost forest — and its haunting significance — to hundreds, if not thousands, of curious tourists. He knows it well. Riding with his dog, Luna, on a stand-up paddleboard — a vessel he recommends because it allows for the best views of the forest from the water — Giles explains the poisoned roots, the subsidence and, if paddling during low tide, the sediment, and the Thunderbird and the Whale.
The tours have been popular, Giles said, with some people choosing to come back for a second or third outing. Those who come back, including Giles himself, have noticed the forest getting slightly more sparse as the dead trees continue to decay and fall over. Giles once guided to the forest a 92-year-old woman who was nearly moved to tears, he said, when she saw how many trees had fallen since her last visit in the 1970s.
The forest is only a mile upstream from Griffiths-Priday State Park and state Route 109, but Giles’ tour stretches closer to four miles, taking visitors upstream of the forest where parts of an old shipwreck lie on the bank, and ending near the piers of an old logging railway that stick up from the river.
The story of the ghost forest is “wildly interesting,” not only because of its cataclysmic significance, but because of elements of local, regional and natural history.
“I’m a strong believer that recreational tourism is an identity that Grays Harbor could take on,” Giles said. “We have so many stories to tell in our region, such a rich history, that it would be a shame to have those stories forgotten. This is one story that I can tell and help preserve.”
It’s also a story that will, at one point or another repeat itself.