Any reports of heavy rail or light rail problems from the earthquake? Classified as 5.2 on Richter scale. 4 after shocks under 3.0 and 4 above with largest 4.0 approximately ~~ 1500 feet NE of primary quake.
My wife reported our dining table moved during the shaking, our house is about 5,000’ from the Surf Line. As such, I would expect that inspections will be taking place to rule out problems with the track.
The shaking was very location dependent, a friend said he didn’t feel anything near downtown, I felt (more heard than felt) a couple of sharp jolts about 10 to 15 seconds apart while located about halfway between the Surfline and epicenter, a co-worker felt shaking going on for a number of seconds. The sharpness of the jolts was a clue that the epicenter was pretty close.
5.2 most people in California literally wouldn’t be bothered by it. California earthquake standards are 7.0 for major infrastructure and buildings and IIRC housing and other structures are rated for 6. Yes they will inspect everything for damage and there might be a few cracked windows or sidewalks or streets nearby but for the most part nothing major will be damaged.
Harold, your conclusion is accurate, but the opening statement is not completely true. Certainly most Californians live far enough away they did not feel the quake. California is a big state.
I live on the coast about 50 miles from the epicenter. The shaking was surprisingly strong for a mere 5.2 quake. For the geologists here our house is on solid rock so there is no soil amplification. My son lives about 50 miles SW of the epicenter in suburban San Diego. Their house is on compacted soil, the shaking was far greater than at our house at the same distance.
I have experienced several 6.0 quakes and two 7.1’s that were about 90 miles from us. A 7.1 has about 90 times the energy as a 5.2, yet the shaking from this quake was about 1/5th that of the Palm Springs 7.1. I clearly felt the P waves prior to the later arriving S waves, normally the P waves would not be felt at 50 miles from a 5.1. Dr. Lucy Jones, CalTech, was interviewed at 11am today and said they were still assembling all the ground motion data. The true epicenter was 18 miles below the surface, it was suggested the intensity at that location was mid 6’s.
USGS tracking for US Earthquakes - today
https://earthquake.usgs.gov/earthquakes/map/?extent=11.1784,-150.55664&extent=58.21702,-39.46289
Local news stated that rail service was suspended for a few hours to allow inspection of the tracks along the Del Mar bluffs. Speed restrictions were put in place as well.
I did see a BNSF freight train passing through Encinitas this evening.
As an aside, in the northern Lower Peninsula of Michigan they had a catastrophic ice storm that took out 95+% of electric power in several counties and also took down some emergency communication towers. Some mobile towers were borrowed from California, but their geolocation software was not reset. When the California earthquake alert went out, people in that Michigan area got earthquake notices. I can imagine those without power for a week in freezing temps who were just getting their electricity back, were somewhat flabbergasted.
That’s a good story - I think I’d be wondering “what in the …” was going on.
I did hear about some minor fallen rock reports from what looks like the foothills of Palomar Mountain. The USGS page on yesterdays earthquake stated that there was very minimal damage. One of the more interesting details was that the maximum ground acceleration was from “high frequency” shaking, where high means >1Hz. Note that the energy of the quake and much of the damage is from low frequency shaking.
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Here in Fallbrook the earthquake was measured at 6.7, and we’re not too far from Julian, maybe an hour or so. No power outages, no damage to water mains or anything, that I know of.
I was in Poway when the earthquake occurred and I was more aware of hearing the building’s response (though something really heavy was dropped on the roof) as opposed to feeling any motion. As mentioned before, there were two loud bangs spaced an number of seconds apart. The sharp sound led me to believe the epicenter was close. The lack of any flicker in the power suggested that the quake was not a large one, even though it was the strongest quake on April 14th.
Another interesting tidbit was seeing a plot of station reports with distance from the epicenter and measured acceleration. One of the sites with the highest acceleration for its distance was Rawhide Ranch, which is about 2 miles west of I-15 on West Lilac Road (obviously just south of you). This goes along with my impression that the ground motion was focused in the NW/SE axis.
I wonder what it would have been like walking near the center of the West Lilac Road bridge over I-15 during the quake.
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I would guess absolutely horrifying if you fear earthquakes. That’s the largest span near me, and considering its quite high over 8 lanes of 65 mph traffic, I could definitely understand someone panicking. I personally don’t get nervous during quakes, just cautious. The bridge would probably be a great vantage point to see the tremors on the ground though.
When I drove OTR I felt multiple earthquakes in California. Mostly from my experience it was like a shudder in my steering. But the one’s I experienced were all less than 5.5. The hurricanes were a different story.
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The bridge in question is a 2 lane concrete arch bridge with a span of about 700’. I-15 is about 150 - 200’ below in the cut that was dug out from underneath. Work started in 1977 and that section of I-15 was opened for traffic in Feb 1980 - the 1977 start date is significant as by then CalTrans had implemented the lessons learned from the 1971 Sylmar quake.
40 years ago, I often would be walking across that bridge as part of my morning exercise, hence my curiosity about how it respond to an earthquake.
This does make me wonder about the I-5 bridge over the Surfline in the northwestern corner of Camp Pendelton. That bridge dates back to 1964 and I don’t know if the supporting columns got the post 1989 reinforcement treatment. OTOH, CalTrans did add crash walls around the columns in preparation for double tracking under the bridge - Mudchicken stated that the AT&SF wanted the crash walls when the bridge was built in 1964.
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An article that mentions some of the seismic retrofits made to the bridge:
Thanks for the link. I remember a woman telling me that she understood the bridge was designed by a woman - looks like she heard wrong. I took hwy 395 on my first visit to Orange Empire Railway Museum in Dec 1976 and was impressed by the rural nature around where the bridge was to be built. A year later I was disappointed to see the construction spoiling the rural character of the area. Excavation under the bridge was still going on when crossing it in April 1979 to get a first look at what ended up being my first house.
Noting what was involved with the construction of I-15, I think that running 220mph track through that area would be a civil engineering nightmare.
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Thankfully the bridge is still the most developed part of the Lilac area. Such a beautiful part of Fallbrook, and I only live a couple miles away. Were there plans to route that high speed line along the 15 for the hilly portion from Escondido up to Temecula or something?
The plan for the LA area to SAN high speed rail link was to roughly follow I-15 to Mira Mesa and then cut over to the Surf Line - possibly about where the line crosses under Miramar Road. IMHO, a 120mph line from the Inland Empire to SAN would make more sense and use the money saved to tunnel between Rose Canyon and Sorrento Valley along with fixing Del Mar - though the biggest expense is to fix the mess in San Clemente.
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In that case I would wonder if they would consider constructing a station at the CA-76 and I-15 junction to bring rail service back to Fallbrook after all these years. With the park & ride there by the 395 and the development going on at Horse Creek I could see that being a prime location.