a 1.0 magnitude earthquake stuck at the center of Mt. Rainier. You may think to yourself that this is just a tiny earthquake, no need to stress or worry….but….you would be wrong. This is a massive Stratovolcano, that stands over 14 thousand feet tall, and has a huge hollow magma center directly beneath it’s peak.
This earthquake’s epicenter was at 0.9 km below the surface. If you understand that Mt. Rainier is the largest mountain in our state, and an active volcano to boot, you would know this is not good. Any seismologist will tell you, shallow quakes are the worst.
The actual earthquakes though, are the least of your worries. What you need to understand is the amount of water that is sitting at the top of this volcano, held frozen in “25” beautiful glaciers.
This is 35 square miles, on average over 100 feet deep of frozen ice, the headwaters to 5 major rivers in our area.
Mount Rainier has an active hydrothermal system, which acts like an acidic sauna that essentially steams the mountain’s rocky interior into soft, gooey clay. The rock eventually becomes so weak that it can collapse under it own weight. This ice does its share of damage, freezing and expanding, slowly eroding the volcanic rocks, and dripping melted water into the acidic interior. But the resulting collapse becomes a massive lahar, that buries everything in it’s path with mud, water and debris. There are over 100,000 people living on top of old lahar debris below the mountain. Lahars can travel at over 20-40 miles per hour!
We have hundreds of earthquakes, daily here in the North West, due to all the fault lines running up and down the coastline.
But if Rainier is waking up, the enormous mudslides and flooding would wipe out tens of 1000’s of acres of land and people, long before any lava flows would reach them. This isn’t something you can out drive…this is not something you can out run. This is imminent danger you cannot stop.
Quakes are not a huge problem unless you happen to work in a skyscraper, or may be in the new underground tunnel being dug under Seattle.
The problem that faces the entire Kent, Puyallup, and Tacoma areas is not the tiny earthquakes, but the shallowness of these earthquakes. The first one this morning was almost 15 km below the surface of Seattle, but the one that hit a few hours ago, was AT THE SURFACE!!!
So were the quakes that hit BC Canada this morning, and just a few hours ago, the last quake was also at the surface. Surface quakes are much more dangerous for humans, but also can trigger volcanic activity.
Volcanic activity is also known to trigger earthquakes. For example, swarms of small earthquakes, rarely larger than M5, can accompany the upward movement of magma through the Earth’s crust. Also, large volumes of magma that rise from deep within the lower crust to shallower depths are thought to perturb the stress field around a volcano, possibly triggering small earthquakes up to 25 km away.
Deep large magnitude earthquakes can also trigger volcanic activity, either by pulling the land apart and creating venting or by compressing and expanding the magma reservoir pressure. Some seismic waves can even cause bubbles to form, creating “overturn” which means gas poor magma sinks and gas rich magma rises…and rises.
We have numerous earthquakes we know nothing about, but when they become shallow, and are centered in our largest mountains, and most horrifying of all, our largest volcano, this is when you need to prepare.
I don’t want to scare people, but I do want to warn you, as of this moment, be prepared. Check your disaster kits, and get them updated if necessary. To see quakes recorded at under a kilometer below Mt. Rainier is very scary to me…and to be honest, I have a bad feeling about this, or I wouldn’t have bothered writing about it.
Other than all that, have a wonderful evening! 😉