Frank Slide, Crowsnest Pass, Alberta

One of the greatest things about Alberta, is that there is an official long weekend almost every month! Some Long Weekends are more popular than others - like the May Long Weekend...and the August Long Weekend... and the February Long ... ok - really, we love them all!!

 

BUT, the good thing about the August Long Weekend is that it's always hot and sunny! (At least where WE go - I'm just saying that part for all my friends who spent last August Long in the rain...sorry).

 

We decided to go camping in Hungry Horse, Montana, with some long-time friends.

 

The BEST route from Calgary to Hungry Horse is through the Crowsnest Pass and Fernie, BC. However, for some reason, Google Maps goes a different way... OUR trip (through the Crowsnest took about 4 1/2-5 hours.. our friends followed Google, and their trip took them NINE HOURS!! (They went over the Going to the Sun Highway...
Google THAT! 
http://www.nps.gov/glac/planyourvisit/goingtothesunroad.htm and http://visitmt.com/listing/categories_NET/MoreInfo.aspx?idrrecordid=9646)

 

Anyway - we went the right way - through the Crowsnest Pass.

The most obvious point of interest going through the Crowsnest is Frank's Slide. Even if you don't know WHAT it is when you are going through, you still definitely know that Something important happened there.

 

http://www.history.alberta.ca/frankslide tells us what happened:

"On April 29, 1903, at 4:10 a.m., 82 million tonnes (30 million cubic metres) of limestone crashed from the summit of Turtle Mountain and buried a portion of the sleeping community of Frank in the valley below."

 

Sadly and tragically, an estimated 90 people (of the 600 inhabitants) were killed. It's an estimate, because most bodies could not be recovered. (The rocks are between 50-150 deep/15-45 meters deep).

The area that broke off was approximately 1 kilometer (0.6 miles) wide, 425 meters (1,400 feet) high, and 150 meters (500 feet) deep - approximately 82 million metric tonnes (9o million tons) of rock. The article says that, to put that into perspective, this means that if you took the fallen rocks and put built a wall 1 meter wide & 6 meters high, it would reach from Victoria, BC to Halifax, Nova Scotia (from sea-to-shining-sea), which, according to Google Maps (and we've already discussed its choice of routes) is approximately 6,145 kms/3,818 miles.

 

Roar from the slide could be heard as far away as Cochrane AB (200 km/120 miles away). People closer to Frank (or on the other side of town) reported that the sound of the slide lasted about 100 seconds, and based on how far the rocks extend, the article says that "scientists estimate that the rocks were moving at speeds up to 120 km/hr (70 mi/hr)"!!

When you see it, and consider how it's even possible (the deadliest landslide in Canadian history) for that many rocks to travel that far, or to even fall to begin with.

Well, there was a LOT going on with that mountain (which, as I mentioned, is called Turtle Mountain).

 

Apparently, it's called Turtle Mountain because, before the Slide, it was shaped LIKE a turtle, and not because it's moving slowly. (By the way, there's another mountain nearby that is also shaped like a turtle, and I'll probably include that picture...but it's not THIS Turtle Mountain.)

 

But, speaking of moving slowly... the Alberta Geological Survey has started monitoring the Mountain's structure and (in)stability, in order to provide the residents living below of any future "catastrophic avalanches" as well as to " understand the mechanics of slowly moving rock masses."
(http://www.ags.gov.ab.ca/geohazards/turtle_mountain/index.html

 

I guess, looking back, it's obvious that the Mountain, in 1903, was completely unstable. Many MANY things contributed to the Disaster, among which are (in summary):

• "The previously horizontal layers of sedimentary rock had been folded during the mountain building process until almost vertical" - you've seen it when in the mountains, right? the layers of rocks - I'm going to include a few pictures of mountains near Jasper (Alberta) that have been folded, too, but, only to about a 45 degree angle.
  
• The Turtle Mountain Thrust Fault runs through the mountain. THROUGH! (A "thrust fault line" is a type of break in the earth's crust, in which (by my understanding) lower rock layers are pushed up and over higher rock layers...which often means that older rock layers are then layered above younger rock layers...)
• There's no way for me to explain this one, except by exact quote from the http://www.history.alberta.ca/frankslide website: "The erosion by water and ice of sandstone and shale layers on the lower half of the mountain beneath the older layers of limestone on the upper half of the mountain created a significant overhang. Large surface cracks along the summit of the mountain allowed water to enter deep within Turtle Mountain . Water continued to eat away at the limestone and the freezing and thawing action of water and ice worked to widen the cracks, creating even more instability." (I'm sorry - all of my attempts to summarize, were just the same exact words in different orders...if this doesn't make sense - email me, and I'll try to explain.)
• and finally, on top of ALL of the above - vertical sedimentary rock, a fault line, erosion... they decided, in 1900, that it'd be the perfect location to mine coal.

So, the situation is: The Mountain is still vertical, there is still erosion, AND there is still a town beneath it, in which people live...

We've been in the area, camping (possible topic of a future blog, because it's a beautiful site - a few miles to the West), at night, when everything is really still... and there isn't even wind to disrupt the silence... somewhere, at some time, a giant rock will roll down the nearby mountain, and I can tell you first-hand - IT CREEPS ME OUT!!!!!

 

Turtle Mountain continues to move, "they" say, by a few millimeters a year, toward the northeast, toward the valley below.

 

This time, though, there's technology... and precedence. There are over 80 sensors on Turtle Mountain now. Scientists .. "estimate" that there probably won't be another landslide like that one... any time soon... the mountain is moving "too slow" - "Turtle-like"...

 

Still... THE MOUNTAIN IS MOVING!! LISTEN!!! "Hopefully", say they, "there's no earthquake"...

I have driven through Frank Slide probably... (without exaggeration)...maybe 250 times... and every time, I feel compelled to take pictures (and yet, I am finding very few in my collection - must label better). I always want to stop. (We rarely do stop since we are usually on our way to somewhere else, but sometimes!)

You just can't believe the size of some of the rocks! With the size and distance, it's impossible to know just how small you are and how big they are, until you are standing right beside them. (One of these pictures - the one in snow (obviously not August Long Weekend - there's me perpetuating the idea that Canada is always covered in snow)- is me and a friend beside one that really didn't look that big from the road...and, thinking it was smaller, it seemed alot closer to the road...) You should absolutely get out of your car, once in awhile, and experience this site. (I'm sure it goes without saying, but you have to remember that it's a solemn place, to be respected, like a cemetery... )

 

There's also an Interpretation Center (to which, I'm embarrassed to say, I have not yet been.) The same website gives an overview of the Interpretation Center, too, as well as additional facts and features of the Disaster of Frank Slide.

 

Tomorrow - Fernie, British Columbia.