By Sheldon Greaves
Long-time readers of this blog will remember nearly two years ago when I reported on a field trip to the Kennecott copper mine near Salt Lake City, UT.
For those of you unfamiliar with this operation, besides the Great Wall of China, the open-pit mine is the only other manmade object visible from space. It measures about a kilometer across and four kilometers deep. Mine engineers had monitored signs that a shift in the ground was coming, and on Wednesday night it came:
While the slide itself was expected, the size and scale was larger than predicted. Here are some more details from this report via the Deseret News:
The University of Utah seismograph station recorded the slide as a magnitude 2.4 shake.
"There are a lot of factors that go into ground movement in a mining operation," [Kyle Bennett, spokesman for Rio Tinto's Utah Kennecott Copper] said, listing composition of the material, rain, thawing, runoff water and mine work itself. "It's kind of a combination of factors that make something like this happen."
The landslide occurred Wednesday night in the northeast section of the mine. No workers were injured, but roads, buildings and vehicles inside the pit were damaged.
Kennecott was aware of the impending slide and apprised employees of the situation as it developed, Bennett said. Company engineers detected movement in the ground as far back as February.
The U. seismograph station provides some insight into the enormity of the slide. It recorded two events in the mine at 9:30 p.m. and 11:05 p.m., with the first registering magnitude 2.4, said seismologist Katherine Whidden.
In my field trip report, I made mention of the gigantic trucks used to haul ore from the mining face to a facility that places it on a very long conveyer which leads to an off-site smelting facility. here is a picture that gives you some idea of the size of those trucks.
That gives some context for this shot, showing some of the aftermath of the landslide:
Not surprisingly, the mine is closed while the impact of this event is assessed. No one is talking layoffs or furloughs at the moment, although rumor has it that Rio Tinto may need to change their business model in light of this event.
I want to thank my cousin John Greaves, who not only brought this event to my attention, but took me to visit Kennecott back when I was in town. Â Thanks, cuz.