Around 4 pm today our house shook. Might not be unusual elsewhere but that was 300 tons or so moving around here, a lot of it directly overhead. We aren’t bothered by low-flying planes or high winds so this really got my attention. Grabbed my feline buddy and headed outside. Turned out to be a 4.5 centered 50 miles east of here. Lasted upwards of a minute.
I knew when I built this concrete underground house that it didn’t even start to satisfy California’s seismic code, but this is Virginia for Pete’s sake. I’m engineered for 200 tons overhead and it certainly better stay up there. Tomorrow, in better light, I’ll be taking a good look at those concrete columns, the weak points.
This one was reportedly felt from Maryland to North Carolina. Anybody else?
PAHS Designer/Builder- Bury it!
Replies
10 or so year ago had a 4.5 in Seattle area, DW upstairs in bath, me down on 2X10s over *' concrete bsmt walls. I hardly felt anything, whe did a little upstairs.
Bigger 6.9 a few years back, me in valley in commercial bldg (lots of fluor lights came down) DW home, no damage but everything moving lots, DW downstairs, hanging onto 10" dia DF center post under 24" dia DF log beam-everything moving. Have 18" by 12 " Re. conc columns at outer ends of beams for second floor that are engineered for 9.5, still moved lots on the 4.5 with DW in the bath, glad she was 'at the post' for the 6.9.
THAT was a very minor earthquake. BAD is when everything in the kitchen cabinets is thrown onto the floor and the china hutch falls on its face. During a bad EQ, you cant get out of bed if you tried. Dont worry, if you cant stick your finger thru any cracks that opened up during the EQ
4.5 sheesh...
South Carolina has recorded a 7.6, which would shake you up a bit, but that was in 1886. http://www.dnr.state.sc.us/geology/earthqua2.htm The strongest I could find for North Carolina was 7.2 in 1811.
The largest in the U.S. was a bit stronger - 9.6 in Alaska in 1964. I saw the after effects of that quake in Anchorage in about 1970. Some areas still looked almost like a war zone... http://neic.usgs.gov/neis/eq_depot/usa/1964_03_28.html
The USGS earthquake intensity map for the US through 1985 is rather interesting, although they must be using a different rating scale than I am used to (probably the Modified Mercalli, which goes from 0-12) http://www.ngdc.noaa.gov/seg/hazard/img/usaint.jpg,
Oh, forgot to mention the New Madrid, Missouri quake. At something over 8.0 it was one of the strongest earthquakes in the continental US - undoubtedly the strongest outside the west coast.
http://newmadridonline.tripod.com/earthquakes/eb/index.htm
Tom, I live in Fredericksburg and almost all of us felt it here. We also had another small one around here about a year ago. Nothing like the one I experienced in L.A. a few years back. Jay
We felt it here in Richmond. More like a long steady vibration than the movement in San Diego I've felt. Probably lasted 20 seconds, no damage found, but heard some nat gas lines were leaking in the Petersburg area.
As expected, 911 was jambed with so many non-emergency calls, that they asked all tv stations to request cease fire. Paul
Brings a whole new meaning to "Rock and Roll", huh?
I have only been through two mild ones, but both really scared me!
darcy
After the last quake out here (my first) we developed a new rule at work. Anyone between me and the door needs to move faster. I worked in a building that looks like a borg spaceship built into the side of a hill. All I could think of was a bumpy ride on a layer of mud down to the Willamette a mile away.
Isn't it funny just how fast you figure out what is going on? Took two shakes and I was up and gone!