The Ring of Fire, Geology & Earthquakes

 

You know when you’re at a meeting and the host asks you to share something no one knows about you… Let’s pretend we are doing that today.

 

Hi! I’m Alicia and I love geology. Geology is the study of rocks, how rocks are formed, and why. And I totally nerd out on it!

 

While most of my friends were taking chemistry and advanced bio in high school, I was the kid who took geology and couldn’t wait to scope out a field trip to Black Canyon of the Gunnison, with my class to show them all about geography, and Colorado, how rocks work, and why rocks are… well, rocks!

 

So I love rocks, I love ’em. It’s a weird thing that I inherited from my grandfather who was a passionate gemologist and gold miner (a literal gold miner) for most of my life.

 

The Ring of Fire

This is the reason we’re talking about geology and disasters because I am an emergency management consultant who loves geology (see above opening rant! lol), in particular, geology and earthquakes because they’re so tightly tied, especially around the ring of fire.

 

I was reading an article and found an idea I absolutely love and had to share, and expand on a bit.

 

They discussed an idea they called “a layer cake of geology nightmares ‘. What resonated with me most was how engineering on top of soil that’s actually wobbly and has no solidity to it is really incredibly dangerous.

 

This quote was so powerful and truly summed it up in a neat nutshell why earthquakes exist on the ring of fire,

 

“Most hazards faced by the city of Seattle result from the area’s geology and climate. The blend of conditions – high-density urbanization with high seismic and volcanic activity, steep terrain, and so much rain – means that hazards do not occur alone. An event in one category should be expected to trigger events in others.”

 

The world’s greatest earthquake belt, the circum-Pacific seismic belt, is found along the rim of the Pacific Ocean, where about 81 percent of our planet’s largest earthquakes occur. It has earned the nickname “Ring of Fire”.

 

Why do so many earthquakes originate in this region? The belt exists along boundaries of tectonic plates, where plates of mostly oceanic crust are sinking (or subducting) beneath another plate. Earthquakes in these subduction zones are caused by slip between plates and rupture within plates.

 

 

 

Why earthquakes on the ring of fire are so dangerous

Earthquakes of historic proportions occur a few hundred years apart but can be wildly destructive in the span of a few minutes of shaking.

 

Many residents remember the Nisqually quake of 2001, a magnitude 6.8 earthquake that caused 40 seconds of shaking and injured 200 people causing an estimated $1.5 billion in damages to households in the region, one National Science Foundation study shows.

 

The layers of the cake are what make it dangerous.

 

Seattle’s layer cake starts with a cracked plate, add that the seismic risk under the city itself comes from the Cascadia Fault Zone, which extends from the Cascades to Whidbey Island, running directly under the city and the Sound.

 

Atop our broken cake plate is a crumbly mess of dessert. 

 

The rock and soil under the pavement is a combination of loose gravel and sand deposited when much of the area was covered in glacial ice, as well as finer layers of mud deposited as the glaciers melted and retreated northward. Let’s add peat deposits to the mix – that’s the type of soil often found in Ireland and used at one time in place of coal. It forms in wetlands when plant matter cannot completely decay and instead turns into a layer resembling a soggy sponge.

 

These conditions make areas in the city vulnerable to liquefaction, a process in which wet compacted sediment turns from solid to quicksand when shaking begins, and back to solid again once it stops, trapping submerged objects, vehicles, and segments of buildings.

 

Many neighborhoods surrounding Elliott Bay are also at risk for tsunami inundation after an earthquake.

 

So what have we learned and how can we use it?

My biggest takeaway from this article was some social proof that we can take a really complex topic like geology and make it a little bit easier to connect with and understand.

 

It’s not just that we live on a fault line, but a bit more about what is at the core of that wobbly structure.

 

It’s time for city residents to flex their social muscles and get ready for emergencies! Let’s turn this party trivia into a tool that can help build robust connections so our communities are prepared. No stocking up on provisions necessary – let the talking do the work!

 

Let’s use it to fuel preparedness for our communities. A really powerful step forward – having a conversation.

 

We know there are effective ways for city dwellers to get ready for natural disasters. In cities, social connections are far more useful than typical “prepping.” Storing food and water is costly; having a conversation costs nothing.

 

The approach to an evolution of the idea of a “prepper” and the prepper mentality is one of a suburban family as we as what they share about what a post-earthquake scenario really looks like, not the Hollywood version from the latest dystopian hit, proves useful in tackling what has been described as “the worst camping trip of your life.” 

 

In conclusion, earthquakes on the Ring of Fire are dangerous due to the combination of factors such as subduction zones, the Cascadia Fault Zone, and liquefaction. Preparing for a natural disaster like an earthquake requires social preparation instead of stocking up on supplies. Having conversations with family and friends and building connections within communities is more effective than spending money on supplies. Understanding the science (and geology) behind earthquakes can help us better prepare and be more resilient in the face of disasters.