Did Quake Cause the Utah Mine Collapse?

This week's tragic coal-mine collapse in Utah has become the focus of an argument between scientists studying the event and executives at Murray Energy Corp., the company that owns the Crandall Canyon mine. On Monday, University of Utah seismographs recorded shaking near the mine that registered 3.9 on the Richter Scale, and 10 smaller aftershocks over the next day.

The company says the initial quake is what caved in the mine, but seismologists are arguing that the data suggests it was the other way around. They contend that a natural earthquake has a different seismic signature than the shaking produced by a cave-in, and that the data they picked up is more consistent with the latter scenario. Murray Energy, meanwhile, insists that the event was a natural disaster, and that they can prove it. —Gregory Mone

Via AP

Comments

[paula wagner]

I have some questions about this latest mine collapse. Coal mining companies have millions of dollars at their disposal. Why don't they have GPS tracking systems for the minors to carry so in the event of a collapse, they can know where they are? Why isn't the rescue equipment ie, the huge drills, on site instead of having to bring them in which takes hours and sometimes days? Why isn't there close circut TV in the mines? A closed circut is workable. We have tunnels which are monitored in the same way?

[Nick]

Paula,

That's great that you want to keep our miners safe, but if you think about your GPS suggestion for a bit longer, I think you'll find why that hasn't been implemented yet. The receivers have to communicate with a satellite, and the signals they use don't penetrate solid objects very well (for example, when I go under a bridge, my XM satellite radio will cut out for a second). As for keeping the drilling machinery on-site, the equipment is expensive to own and to maintain. If there was one at every mine, it would probably suffer from lack of regular maintenance and/or use, and then maybe wouldn't even work when you needed it to. The camera idea is a good one, you'd just have to make sure that the cables connecting the camera network to the surface wouldn't be severed by a collapse, or damaged during normal mine operations.
The cynical answer to your question about why hasn't something already been done though is that Americans don't want to pay more for their electricity. Therefore the pressure is on for the mining companies to keep costs low.
On the bright side, we could be like China where (I forgot the number I heard on NPR this weekend) something like 2,000 miners died last year, compared to the 47 we lost in the States last year.

[Frank B]

Up until 2006, this Crandall Canyon mine had been using continuous mining methods (By Patty Henetz The Salt Lake Tribune- 8/8) on North and South sides of this current room and pillar operation.

Continuous mining leaves a lot of loose collaped overburden (with many huge voids). Retreat mining with this loose unstable/unsettled soil in this mountain valley would be very risky and reckless because of the lateral instability compounding the earthquake like shocks down the center of the valley.

Although the mine operation had permission to do "retreat mining" they could only do it under certain conditions (messures as prescribed by soil consultants, training for the miners, additional safety/rescure precautions,emergency ventilation, and ADDITIONAL LIABILITY INSURANCE)

Bob Murray's misleading and disputed statements regarding what was going on, leads one to guess that the proper steps and precautions were not taken. And that the proper insurance was not in effect at the time of the collapse. Unfortunately disasters resulting from retreat mining cover esentially all incriminating evidence.

We hope this is not another Katrine style bungling involving politics (MSA administration) and lobbist and sell-outs (company and union). Frank B

[Caroll]

What is hard for most people to comprenhend is the environment underground. Even if we could implement some sort of CCTv or a radio link underground, the environment is always expanding. There would have to be an extention of these links to the working faces of the mine every day. Some mines expand 100 feet in a shift! Not to mention, that if we do extend this link forward to the workers, the likelihood of a wire remaining intact after ~200 tons of sharp rocks falls on it are less than good. Radio contact is "Line of Sight" undergound, and if stone blocks the escape, it also blocks the communication. There is little that can be done to prevent these "acts of god", other than to take extreme care in mine design and methods, and ensure that there is a factor of protection. Always remember to err on the side of caution rather than profit, and things will be just fine.