Thread: Small Quake

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Small quake???? Is that like being a little pregnant?????

I guess so there are going to be some people getting shaken up!!!

RICHARD

5.2 isn't exactly small! It is very fortunate that there was not more damage and injury from the one in Illinois. Consider that the Richter Scale is a logarithmic scale: a 5 is ten times greater than a 4, and a 6 is ten times greater than a 5. Most of the seriously damaging shakers in California are between 5 and 6; the ones greater than 6 are really rough.

Back in the eighties, the Whittier Narrows quake, which was, if I recall, a 5.4, did a tremendous amount of damage to buildings and infrastructure; it moved a power transformer in one of our substations, about six miles from the epicenter, off of it's pad: the transformer weighed 850,000 pounds, and was welded to steel plates anchored four feet deep in a monolithic concrete pad 25 feet wide, 50 feet long, and seven feet deep. Perhaps it would be more correct to say that the quake moved the pad out from under the transformer; but, never the less, a lot of serious power is released in one of those shaky things. At the station where I was based, about forty miles away from the epicenter, all of the towers and lines and structures took on the resemblance of a vertical "spaghetti garden" for a quite a few seconds; they all waved and danced around like they were made of some soft wiggly stuff, instead of heavy steel, and many large flanged joints were shaken loose; we had oil and water leaks galore.

Our house is double brick with a lot of big windows, the way the house was shaking I was surprised it didn't do any damage.

Richard

just got woke up to another one a few mins ago!

Never got experience earthquakes here in Oklahoma, we are to busy dodging Tornado's!

Surprisingly, we do get a few earthquakes in the northeast. Had one a few years back with an epicenter about 25 miles east. Whole lot of shaking going on that evening. I thought someone had run a truck into the side of the house. Yesterday we had two tornadoes touch down a few miles up the road. Fortunately not much damage there or here. We also get an occasional hurricane and my place routinely gets winds between 25 and 45 mph.

Tornadoes scare me most of all and having experience two here a few years back and one in Olathe KS a few years ago, I just don't think I could live where they roam frequently. I'd be having mini-strokes every time it thundered.

It's funny what scares us. My house sits on a huge slab of bedrock, I believe(my middle brother is the geologist in the family). It survived the 1906 earthquake in S.F. that demolished most of the old victorians North and South of me. Our town supposedly has this deep slab of rock, that buffers and protects it in earthquakes. Petaluma is known to have some of the finest collection of old iron fron buildings in California, because they all survived the Big one(1906).
We added 1500 square feet to the back of our little shack a few years ago. It took over a year for the permits, and in the end the plans included a huge steel beam to be built into the rear frame work for earthquake retrofitting. The problems we encountered were interesting. First of all the new structure is tied to the old house with sort of a slip joint. The fear was in an earthquake, the new addition would be stiffer than the 1858 original portion and would litterally tear the old house apart in the event of an earthquake.
Well shortly after it was built we had a 4.something with an epicenter closeby hit. I've never heard anything like it in my life. I asked my wife to run to the driveway, because I thought someone ran their car or truck into the side of the house. Something about the steel beam, made this almost car crash jolt and sound.Here is a picture of the beam. The engineer for our plans builds bridges for a living so I know it was a bit overkill at the time, but that's ok with us!