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Utah Mine Collapse 2007
The Utah Mine collapsed on August 6, 2007, seismic waves were recorded and measured at 3.9 magnitude.



Figure 1: Map of Utah showing where the collapse mine is located.
Figure 1: Map of Utah showing where the collapse mine is located.


Background:
Mining is a vital aspect of Utah’s economy. The mining industry has touched all aspects of life throughout Utah and has contributed greatly to the state’s history. Early commercial mining can trace all the way back to 1863 to Colonel Patrick Connor.
The mine at Crandall Canyon dates back to 1983 and the elevation of the entrance is 7,835 feet.


Figure 2: Arial view of the Mine.
Figure 2: Arial view of the Mine.



About the Collapse:
The Utah mine collapse at the Crandall Canyon mine in Emery County, Utah. Around the same time as the collapse, a seismometer recorded a seismic wave that registered as a 3.9 magnitude. Shortly after the collapse, the co-owner of the mine, Robert Murray, stated that an earthquake triggered the mine, and not the miners. Despite what Robert Murray said, people were still not sure if the earthquake trigged the collapse, or if it was just the collapse itself. What people did not understand is how or why the mine collapsed. Looking back at the techniques miners used for the past seventy years, it became easier to see the reason behind the collapse. In the early years at the mine, from 1939 to 1955, miners used a “room and pillar” method. This basically meant that workers removed coal, but left pillars to support the ceiling. Then from 1997 to 2003, miners updated their method, and started to remove slices of the leftover pillars from before which created new pillars, this technique is called “long-wall”. More recently, in 2007, the same year as the collapse, miners used a final method called “retreat mining”; in which pillars of coal are used to hold up an area of the mine's roof. When that area is completely mined, the company pulls the pillar and grabs the useful coal, causing an intentional collapse.


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Figure 3: Shows the location of the collapse and it gives a visual of the mine, where within it the collapse occured and how it trapped its inhabitants.


The Press and Search for Survivors:
In a press conference, a reporter asks Murray to describe the type of work the miners were doing at the time of the collapse. In the reporters question, he specifically asks about “retreat mining”, and how that type of work differs from other mining techniques the miners had. Robert Murrary immediately becomes angry at this question and starts placing the blame on the other people and organizations. Murray continues to state that “retreat mining had absolutely nothing to do with the disaster that happened or that retreat mining was never taking place when the collapse happened.” Weather Murrary wanted to convince himself that retreat mining had nothing to do with the collapse, was his choice, however there are many reports that state the opposite. Retreat mining was the reason the Crandall Canyon mine had collapsed, and it was the reason that it had trapped six men inside that enabled them to reach contact with anyone outside the mine. Twelve hours after the collapse, and still no contact was made by rescue teams. Many rescue missions were in affect for hours upon hours in hopes of reaching and rescuing the six trapped miners. On August 16th an unfortunate tragedy occurred, three men died while trying to rescue the trapped miners. Efforts waged on despite the rescuers accidental deaths; holes were drilled and tunnels were burrowed out in an attempt to help the miners escape, microphones were lowered into the ground in an effort to pick up any noise, but unfortunately nine days had already passed and rescuers were estimating another five to seven days to complete the dig. Although rescuers continued for a few more days, federal authorize ceased searching for the trapped miners, stating that they’ve run out of options, leaving family and friends devastated. In a final report of why searching was stopped, many tests showed that underground oxygen levels were too low to sustain human life and that the pressure from the force of the initial explosion caused miners to be buried under tons of rock. The grief of the disaster and strenuous search and rescue teams may have ended, but the lawsuits and course cases have not.


Figure 4: Firefighters searching for survivors.
Figure 4: Firefighters searching for survivors.


Lawsuit:
A lawsuit was filed in the 3rd District Court that contends that Murray Energy Corporation and its affiliates knowingly continued to perform risky retreat mining last summer. A bounce is a violent ejection of rock and coal from the mine's ribs, roof or floor. In a further report of the lawsuit, court papers continue to state that “Ohio-based Murray Energy and others of being "motivated by avarice and greed at the expense of safety and human life" in continuing to extract coal (cbc). Murray still insisted that the collapse was caused by an earthquake, despite evidence that supports the fact that the mine collapse caused the 3.9 magnitude earthquake. The Federal Mine Safety and Health Administration concluded last year that faulty design and inadequate reporting of previous coal outbursts, contributed to the rock fall. The agency has proposed $1.85 million in fines against the mine operators and engineers. In regards to the lawsuit, a settlement was reached, although the amount of money awarded was disclosed, lawyers for the families said the settlement exceeded the than $20 million paid to families of 27 victims of a 1984 explosion and fire at the closed Wilberg mine in the same Utah coal district. For the surviving family members and friends of the miners who lost their lives, there is no amount of money will be enough to change what had happened to them on August 6, 2007.

Figure 5: A mother holds her daughter as they wait to hear news about her husband.
Figure 5: A mother holds her daughter as they wait to hear news about her husband.
Figure 6: A memorial set up by the mine, in memory of the 6 miners trapped inside and three rescure workers.
Figure 6: A memorial set up by the mine, in memory of the 6 miners trapped inside and three rescure workers.


Seismic Part of the Collapse:
Some say that the collapse caused the earthquake, while others say an earthquake caused the collapse. Seismologist Harley Benz, who is in charge of the National Earthquake Information Center in Golden, Colorado said “The reasons to suspect that the Crandall Canyon Mine's cave-in was responsible for the seismic activity included the epicenter's proximity to the mine and shallow depth and the nature of the signal itself” (analysis). It took a year for investigators, seismologists, and a team of experts to finally come to the conclusion that the mine collapse in-fact produced the seismic waves. Jim Pechmann, a seismologist at the University of Utah stated that as the rescuers searched underground, "the coal just exploded from one of the mine walls and filled up a lot of the mine tunnel where these miners were working," It wasn't so much that the roof fell on them — it was that the pillars just broke apart suddenly and violently" (geotimes). The seismic waves were not the cause of the mine collapsing. The seismic waves were produced becuase of the collapse. There is no evidence of the earthquake just the collapse.

Figure 7: Shows earthquakes as blue, underground explosions in red, and the crap collapes in green.
Figure 7: Shows earthquakes as blue, underground explosions in red, and the crap collapes in green.
Figure 8: A truck brings a seismic listening equipment to the mine.
Figure 8: A truck brings a seismic listening equipment to the mine.


Sources:
"BBC NEWS | Americas | Utah mine rescue efforts halted."
BBC NEWS | News Front Page. Web. 02 Dec. 2009. <http://news.bbc.co.uk/2/hi/americas/6952180.stm>.

http://www.physorg.com/news105974998.html
http://www.cbsnews.com/elements/2007/08/07/in_depth_us/photoessay3140271_1_2_photo.shtml
http://www.usatoday.com/news/nation/2007-08-06-utah-earthquake_N.htm
http://www.sciencemag.org/cgi/content/abstract/321/5886/217
http://www.pbs.org/newshour/updates/weather/july-dec07/mine_08-17.html