Why Does the Cascadia Earthquake Anniversary Matter?


How do we prepare for something we have never experienced or can’t even imagine? Given that the last Cascadia Subduction Zone earthquake happened in 1700, almost 180 years before the lightbulb was invented, it’s no wonder many of us have a hard time grasping the possibility. As humans, we tend to prepare for events that we believe have a high likelihood of happening, so when something isn’t in our collective memory, it seems unreal.

The only people who experienced the 1700 Cascadia Megaquake were the Native First Nations tribes who lived along the Pacific coast and inland valleys. The shaking, which lasted several minutes, started around 9pm and woke people up from their sleep. The subsequent tsunami wiped out entire villages along the coast that night. Stories of this earthquake were passed down through the generations.

It was 100 years after this great earthquake that Lewis and Clark reached the Pacific Ocean and it would be another 50 years before the cities of Portland and Seattle were founded. When these cities were built, the settlers were oblivious of the danger of earthquakes in our region. In fact, it was not until the late 1980’s that scientists proved the significant risk of the Cascadia Subduction Zone.

So why does this anniversary matter? It matters because it reminds us that Cascadia Megaquakes really do happen, and will again and again. It also reminds us that the Cascadia fault has been building up pressure since 1700 and this pressure will be released in the form of a megaquake. 

Spread the preparedness word!