preliminary reports that no immediate injuries. One interesting item there was a 48 second warning before the 10:33 PDT of the earthquake at Cal Tech sizemmology lab. Several Amtrak trains appear to be stopped after looking at tracking sites.
https://www.theguardian.com/us-news/2019/jul/04/earthquake-southern-california-largest-in-decades
Just enough lead to get a text out saying “Hang On!”
The quake was strong enough to be felt from Bakersfield to Las Vegas and Long Beach, nothing felt here in the SFBA.
No Amtrak or Metrolink service alerts have been found so far. The BNSF and UP Mojave subs are the closest class I routes and trains may have been stopped for track inspection, but no advisories have been found. Someone on Facebook published video of the quake from the Tehachapi Cable webcam.
The only significant damage I have read about is in the Ridgecrest area close to the epicenter; many structure fires and some road cracks have been reported by the news media.
FYI the Los Angeles county earthquake alert system did work but no alert was issued due to the predicted low intensity at that distance.
The Los Angeles Times website has frequent reports and KNX news radio has had continuous coverage and call-ins.
I felt the quake as a gentle rocking motion with a period of 1 to 2 seconds, and not enough to get objects in the house moving.
They showed a road in Trona with a good size crack and some offset in the pavement. Is that rail line still in operation?
Apparently the shock on the fourth was a foreshock, since a 7.1 event hit today Friday at 8:20 pm PDT. Other activities before and after of 5.0 and 5.5, respectively. Good shaking on the Tehachapi cameras.
The same city Ridgecrest had a quake in 1995
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.885.1486&rep=rep1&type=pdf
There’s more to the story, the 1995 quakes continued into 1996.
https://pdfs.semanticscholar.org/4acd/bf4898a26b35159c3aafc4ecd38b0789d1cc.pdf
Satiurday morning EB SW Chief #4 came through Barstow nearly six hours late. WB #3 came through a little later nearly on time.
A 7.1 follow up EQ
The track forces/signal forces within 100/200 miles of the epicenter were out the moment the thing was reported over 4.9… Wonder how many non-solid state relays are still out there floating in a very small container of lightweight oil?
I wonder how long it will be before we find out the damage to the former SDA&E if there is any damage?
How could we tell?[:)]
(That would be a little too far away)
Chuck: [bow][bow][bow]
Distance was one thought; the generally dismal condition of the former SD&AE track at this point was the other thought. I don’t remember the April 9, 1968, Split Mountain quake (6.5) doing much mischief on the SD&AE and that was not far from the ROW (as close as 18 miles or so).
The shaking I felt from the Ridgecrest m7.1 quake was substantially less than the m7.1 quake in Baja taking place Easter 2010. The epicenter for that quake was much closer to the SD&AE line than I was, while Ridgecrest is roughly equidistant from my house and the SD&AE line. The 7.1 Ridgecrest quake caused maybe 3" of motion on a 6’ chandelier.
What’s funny is that the news media said that the Ridgecrest was the strongest to hit California in a couple of decades, while the 2010 quake was barely out of the state.
Differing ground types transmit EQ motions at differing levels.
The 1979 quake in the Imperial Valley shook a lot of the San Diego high rise buildings pretty well, but I was sitting in the dining commons at San Diego State on my coffee break and barely noticed any motion at all, just some slight swaying of suspended light fixtures.
The 2010 Easter quake, on the other hand, rattled the house pretty good for about 20 seconds or so (I live about five miles from SDSU) which was unusual for us.
The 7.1 on Friday was barely noticeable here, probably only because I was sitting quietly in my easy chair.[8D]
I was out running around and taking photos in the Lower Desert of Southern California around twilight Friday, July 5, 2019 when the second big Ridgecrest quake took place. Two photos, one of which is below, are in the “Sunset Route Two-Tracking Updates” thread with a super brief earthquake experience conveyance.
Tell me about it… (very glad my house isn’t built on bay fill.)
The Easter 2010 and last week’s quake were all experienced while sitting in the same house, which rests on sandstone, so I would expect ground motion for most of San Diego County from the Ridgecrest earthquakes to be roughly what I experienced (exceptions would include tidal flats). I would expect that ground motion from the Easter 2010 quake would have been much stronger along the eastern parts of the SD&AE line than it was here a mile away from the Surf Line.
My previous house was built on bedrock in a quiet rural area and I could hear the p-waves from a major quake hit several seconds before the shaking from the s-waves - noise was a bit like lash-up of normally aspirated EMD’s in run 4 from a few hundred feet away. Remember the 1979 El Centro quake along with a couple of temblors in 1986, the 1992 Landers/Big Bear one-two punch and the 1994 Northridge quakes.