My real interest was in the UP though, I had heard about quakes in the Copper Country(aka the Keweenaw) and I wanted to see what the USGS had to say about them. Well I found a map of seismic hazard, see that circle in the top left? that's the Copper Country
A series of unusual occurrences in the Keweenaw Peninsula mining area form a significant part of the seismic history of Michigan. The first disturbance was on July 26, 1905 at about 6:20 in the evening. At Calumet there occurred what appeared to be a terrific explosion. Chimneys fell with a crash and plate glass windows were broken (intensity VII). The explosion was heard far down in a mine and the shock was felt all over the Keweenaw Peninsula area and as far away as Marquette, about 70 miles southeast across Lake Superior. Ten months later, on May 26, 1906, a similar phenomenon occurred. Train rails were twisted, and there was a notable sinking of the earth above the Atlantic mine. The disturbance was reported felt over an area about 30 to 40 miles in diameter. Another shock occurred in the same region on January 22, 1909. A rumbling tremor was felt around Houghton and was believed to be caused by the crushing of pillars in a mine.Huh so perhaps they were the result of mine blasting or mishaps and not true earthquakes after all, but I wonder, blasting is done on a schedule and the mine would keep records of that, also local residents would be used to the shaking that accompanies a big blast and I doubt it would have fazed them. Growing up my Da was a miner, we lived over 15 miles away from the mine and yet I can still remember the house rattling a bit on blast day(usually Fridays) and that was with an open pit mine, I'm sure the shocks from a underground(perhaps under your house) mine would be much bigger.
Anyway that my informative blog for the month, I'll go back to drivel tomorrow ;)
:EDIT: I know the text around the graph is unpretty, nothin' I can do about it
2 comments:
I used to live about four miles from a blasting mine and you could just about hear the explosion on a weekly basis.
I also lived four miles from a factory that produced explosives and the day that fucker went up all of our windows crumbled, but only two people died, amazing...
Now I remember a landslide from a hydroelectric station, about 20 miles away, killed about 18 people, from memory a pipe burst and half a mountain slipped onto some posh peoples houses and onto a road, that was a rumble that was more violent than the factory going up.
Nature will always beat what we can do.
I remember being able to hear and feel the blasts at the mine only on occasion when we lived 15 miles away, we moved closer to the mine(only 5 miles away) in 1994 and hearing and feeling that blasts became a weekly occurrence, windows shaking and the whole bit.
I was just pondering if a mine blast could be confused with a seismic occurrence and I just don't think so, not to a people that are used to the mining.
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