Teaching about the Cascadia Subduction Zone in Washington State History
A Lesson Born from Home
This was literally the first lesson I ever created for Washington State History — and it started with the Cascadia Subduction Zone.
I grew up in Grays Harbor County, Washington — the county of perpetual dreariness. The clouds never seemed to leave, and the rain felt endless. After all, we gave birth to Kurt Cobain. The landscape itself feels soaked in melancholy, the moisture and fog constantly ebbing and flowing like breath. There were times, as a kid, when I felt like I’d been birthed from under a rock.
But in that gloom also lived a quiet tension — a collective awareness that the ground beneath us wasn’t as stable as it seemed. We grew up with the phrase “we’re overdue for the Big One.” My social studies teacher used to say that “overdue” wasn’t a scientific term, but still — it stuck with me.
The fact is, geological records prove that the Cascadia Subduction Zone, located about 70 miles off the Pacific Coast, produces a massive earthquake on average every 500 years. The last one struck in January 1700, so powerful it created a “Orphan tsunami” that reached the shores of Japan.
A Personal History with Cataclysm
I survived Mount St. Helens. I experienced 9/11. I was sitting in an internet café in Times Square during the 2003 New York Power Outage. I’ve seen disruption in many forms. But a tsunami — there’s no running from that.
In Grays Harbor County, we have a little area near Aberdeen called Cosmopolis, right by the shopping mall where everyone hung out in the ’80s and early ’90s. That entire area would be twenty feet underwater in a tsunami. There are no two-story buildings to climb for safety. I know the city of Aberdeen well — Cobain’s childhood home sits right in the flood zone. It would be gone.
And there’s only one road leading east out of Aberdeen. If that road is blocked, there’s nowhere to go.
The Purpose Behind the Lesson
This lesson isn’t just another classroom activity. It’s personal — it’s about helping students see the reality of where they live.
The goal is for students to understand the real risk the Cascadia Subduction Zone poses to coastal communities like Grays Harbor and Pacific County. Using resources like the Pacific Northwest Seismic Network (PNSN), students collect, record, and analyze real earthquake data to see just how active our region really is.
The PNSN’s Recent Earthquakes map (pictured above) is an incredible teaching tool. It shows live data from around the Pacific Northwest — magnitudes, depths, locations, and even timestamps of the most recent seismic events.
When students log in, they quickly realize:
Earthquakes happen all the time, every day. Most are too small to feel, but they’re a constant reminder that our region is alive and shifting.
Inside the Classroom: The Cascadia Subduction Zone Lesson
Here’s how the lesson unfolds — adapted from the Emergency Sub Plans: Cascadia Subduction Zone developed by Anthropologist in Heels.
Step 1: Setting the Stage
The class begins with a discussion about recent natural disasters — hurricanes, floods, and earthquakes. Then, we introduce the Cascadia Subduction Zone as a key geological feature of the Pacific Northwest.
Students are asked:
What do you know about tsunamis?
What might happen to our coastal towns if a large earthquake occurred offshore?
Step 2: Visualization and Color Coding
Each student receives a Cascadia Subduction Zone coloring map. As they color, they learn to identify geological features — the Juan de Fuca Plate, North American Plate, and the fault line where they meet.
“Okay class, this area you’re coloring red — that’s the Cascadia Subduction Zone. It’s a 600-mile-long fault line capable of producing a magnitude 9 earthquake and a tsunami reaching 100 feet in height.”
Step 3: Data Collection via PNSN
Students navigate to PNSN.org
So overall, this is a very interesting lesson for any student, and it is an important issue for residents of Washington State.
