Naturalist David B Williams has written books about everything from how settlers reshaped the land in Seattle to the history of Puget Sound. His latest is a collection of essays called Wild in Seattle: Stories at the Crossroads of People and Nature.
The essays cover geology, plants and animals in the city, but we wanted to focus on one in particular called "Dead Trees Tell No Lies." Williams is a self-avowed “geo-geek” and in this story, he describes how geologists can read the growth rings of trees for evidence of what happened thousands of years ago. KNKX environment reporter Bellamy Pailthorp met with him among the trees of Saint Edward State Park at the north end of Lake Washington, to learn more about one of the region’s biggest earthquakes.
Click “Listen” above to hear their conversation, or find the transcript below.
Transcript
Note: This transcript is provided for reference only and may contain typos. Please confirm accuracy before quoting.
KNKX Environment reporter Bellamy Pailthorp: David, we're here at Saint Edward Park, sitting at the water's edge among lots of big leaf maples and red alders. And I believe you told me that these trees could point to evidence of a landslide here long ago.
Auhtor David B. Williams: Yeah, that is correct, Bellamy. The trees such as that, the alders and the maples, generally move into areas or grow in areas that have been disturbed. So we see them a lot in Seattle along roads, maybe where there's a little landslide. But if there was a big landslide, such as we know occurred here a little over 1,100 years ago, these would have been the first trees to move into the landscape.
Pailthorp: And so there was a landslide here something like 1,100 years ago that was triggered by one of the biggest earthquakes we know about in the region's history, a magnitude 7 that occurred along the Seattle fault. I understand studying trees that were submerged during that quake and landslide has unlocked many more details about the seismic event. How did scientists even know to look at the trees?
Williams: They know about it because they've known about these submerged forests since the early 1900s. They particularly became well known right after 1916 when the lake level dropped with the building of the Ship Canal, because a couple of boats actually hit the top of these trees that were growing just within the surface, and literally, it is an entire forest that slid into the lake, and the trees are still upright in the bottom of the lake, just as they were in living position.
Pailthorp: Oh, wow. So underwater out here in the lake, pretty much right in front of us, there are submerged old growth doug firs, right, that scientists were able to get samples from and then read the tree rings to decode the natural history here.
Williams: Exactly, that's what happened. So when this earthquake on the Seattle fault hit, the land to the south, was uplifted about 20 feet, and during that movement, because it's very close to the surface, the energy was felt very broadly and very strongly across this entire region. And in three places along Lake Washington, it basically shocked the landscape, causing these three forests to slide in: one up here at Saint Edwards and then two off Mercer Island. So they knew about the trees. They didn't understand how they got there until the early 1990s when they put together the story of the Seattle fault and this movement. But one thing they didn't know was, exactly when did it occur? And they then cut the trees. Sometimes they had to dive underwater with chainsaws, which just sounds like a nutty thing to do. They got the trees, they polish them, and they're basically, as you say, you're able to read those rings and determine when this event occurred.
Pailthorp: And so they found that it was not just around 1,100 years ago?
Williams: Right. They were able to narrow it down to between the fall of 923 and the spring of 924 and the reason - part of - they have that date is one: they lined up all the rings, and they were able to sort of calculate that. They also did radiocarbon dating, and then they compared the rings that they found in Lake Washington and other places with some tree rings found in Vancouver that had already been dated. So they knew how everything sort of lined up there, and everything fit together perfectly. And, yeah, I mean, it's almost if they were opening up a book, and the pages were being opened for the first time ever, and someone came along and was finally able to translate them. And they basically read this record of this massive, massive earthquake in this region. And it is, as you said, one of the largest earthquakes to hit within the last couple thousand years in this area.
Pailthorp: And so surprisingly, they not only found, more exact information about the timing of the quake, they found that there may have actually been two earthquakes that happened around that time, acting as kind of a double blow. Why is that important to know?
Williams: If you think about it, the classic example is, if you have an earthquake, everything shakes, and you don't have anything after it, people are sort of calm. But if you have everything shakes, and then a day later, or two days later, or a week later, you have another one. You've got medical issues, you've got transportation issues, you've got communication issues – all of these things, and then all of a sudden, now you just hit it again, so it just doubles everything and makes it worse. And they had no clue of that, until they were able to pull the trees out.
Pailthorp: So that helps with emergency preparedness. And you conclude your essay "Dead Trees Tell No Lies" with a nod to the importance of science, and the scientists who you say, have observed and been working without agendas in pursuit of truth, at least the scientists you've met. Why is that important to you to point that out?
Williams: I think science is the way I see the world. It's the way many people see the world. It's the way we understand the world. And I've worked with dozens of scientists over the years, interviewed them, been out in the field with them, and I've always felt that they've had a single goal is to better understand the world that is around them, often with the simple quest to help people be aware of the changes that have occurred over time. I mean, how can we understand what's going to happen in the future unless we understand what's been happening in the past? And so much of science is marrying those to the past and the future in the present studies that are going on. And I just love that.
Pailthorp: I should emphasize that this essay, "Dead Trees Tell No Lies," is one of several dozen stories about all kinds of natural things in the city that you publish first in your newsletter, Street Smart Naturalist. And it seems from reading that, that a big motivation of yours is just to get people to stop and notice and to get curious about little things around them. Why do you want people to do that?
Williams: I just want people to be outside. For myself. I love being out there. I love discovering these stories. It has strengthened my relationship to place, as I write in the book. I wasn't born here, I've been trying to naturalize myself to this place, to understand the rhythms, the water, the seasons, the plants, the animals, the geology, and in doing so, I know that I am much happier. Studies show that when you're outdoors and paying attention, you're healthier.
So it all builds together to develop, and I hope my writing helps encourage people to develop these stronger relationships to the world around them. Makes them better, but also it makes it a better place. Because I'd like to think that if you care about the incredible beauty, the incredible diversity of this place you're going to work to want to protect it, and that's really sort of my goal, is having people live with deeper respect and reciprocity about place.
Pailthorp: David B Williams, author of the essay, "Dead Trees Tell No Lies" in the new book Wild in Seattle. Thank you so much for Joining me.
Williams: My pleasure.
