Category Archives: San Bernardino County

Ridgecrest – Part 1

Finally posting the photos from my August 22, 2019 Ridgecrest trip. Part 1, which covers the fault rupture, is finally up. Part 2, which will cover the problems in Poison Canyon and Trona, are coming soon!

Earthquake UPDATES – Mw 7.1 near Ridgecrest

Well, that was strong! I felt it here in San Diego. First time I felt my building sway and it shook for a while. USGS is now reporting the quake as a Mw 7.1, which is 11 times larger than the one yesterday. This, assuming a larger one doesn’t happen, has also been deemed the “main shock” and the 6.4 was the “fore shock”. USGS and Caltech are a bit slow right now. If you felt this one, please let USGS know once their servers are not slow or not working. They need your help!

From Caltrans and CHP, damage reports are coming in of rockfalls on 178 in Poison Canyon, a sinkhole on 178 near the Trona Pinnacles turnoff, and buckling up to 4 feet as well as large cracks in other areas. Do not drive fast through any of the earthquake affected areas. Also be aware that rockfalls will be likely in all the local mountain ranges, so be careful. State 127 near Ibex Pass is covered with rocks, and that is a fair distance away from the epicenter.

http://scedc.caltech.edu/recent/
Working map of all earthquakes in California and Nevada by Caltech. Links to USGS as well on the page.

USGS site now working!
https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/executive

M 6.4 near Searles Lake, CA

Seismic activity map of the Ridgecrest / Searles Lake area as of 12:40 pm July 4, 2019.

At 10:33 am this morning, July 4, 2019, there was a Mw 6.4 earthquake centered a few miles northeast of Ridgecrest, California. The focus of the earthquake was mid-range in depth, about 10.7 km deep. So far, there have been numerous aftershocks ranging up to M 4.7 in size at the time of this writing. The earthquake is the largest to strike southern California in some time. The area to the northwest of the epicenter has been subject to earthquake swarms in the past as well, though usually only up to the M 5.0 range in size.

Shakemap from this morning’s earthquake

https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/executive
USGS summary of the earthquake

Due to the size of the earthquake, I would expect there to be a fair amount of damage to buildings in the Searles Lake, Trona, Pioneer Point, Ridgecrest, and Inyokern areas. If you live in any of these areas, let the USGS know about what happened. Your information is greatly appreciated and will help them better understand the effects of earthquakes.

https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/dyfi/intensity
Did you feel it? Report it to the USGS here!

Cajon Pass Tour – August 12, 2017 – Review

Former Douglas gas station in Devore, CA

The tour began at Devore, CA at about 8:30 am after meeting a friend, who ended up being the only person to show. After a quick briefing on what we were to see, we headed south to Verdemont, where we inspected a freeway overpass that had remained mostly intact from its original 1950’s construction. The bridge rail and approach guard rail was original and relatively untouched. From there, we headed back to Cajon Blvd and viewed the old concrete alignment at Verdemont.

Little League Drive OC over I-215

After Verdemont, we headed back to Devore to see a section of intact 1916 paving, which acts partly as a driveway for an antenna site. The paving, oil macadam, is quite rare to see these days and was pretty cool to see. Despite all it has gone through, the paving was fairly smooth with only a few major potholes. The roadway damage did also offer an opportunity to more closely inspect the paving itself. The aggregate that was used was fairly large by modern standards and appeared to be granite.

Intact 1916 macadam paving at Devore

North on Cajon Blvd, we passed a couple of C-monuments adjacent to the freeway. I first spotted these on a trip a few months ago following the Blue Cut fire. It was nice to see they were still there. Those monuments were also at the point where old Cajon Blvd merges with the “new” Cajon Blvd (the extension from Devore on a new alignment).

Looking toward I-15 at Blue Cut in the former expressway median

Our next stop was at Blue Cut. There, we checked out a plaque commemorating the history of the Blue Cut area. Blue Cut, as it was noted on the plaque, was the location of a toll booth on the original wagon road through here. We also inspected the foundations of the 1940’s weigh station, which was removed not long after the freeway bypassed this section. While we were at Blue Cut, we also watched three trains pass by, one of which was a “fast freight”, which was passing another train.

Salt Lake Trail marker from 1917

Bridge abutments in Crowder Canyon

Moving north from Blue Cut, we stopped briefly at the Debris Cone Creek bridge, then headed toward Cajon Junction. At Cajon Junction, we followed the eastern frontage road south to the end of the road. There, we found the trail monument from 1917, which was placed alongside the roadway just after it was paved. The monument itself was moved to its present location when the freeway was built. This location was also the divergence of the original path through Cajon Pass and the later roads, which eventually became US 66. As it was getting a bit hot, we moved onto our next stop – Cajon Summit.

Between Cajon Junction and Cajon Summit, the old roadway has been greatly modified. Only portions of both directions of the former expressway are still visible. The whole section, however, has been closed since the Blue Cut fire burned the area. This same fire, unfortunately, also took what would have been our lunch stop – the Summit Inn Café. The sign still remains, but the whole business is gone. It may be rebuilt, but only time will tell. So far, the site has only been cleared.

1952 Cleghorn Creek bridge rail

1916 roadway and building foundation

After stopping at the summit, it was time to work our way back down the hill. Instead of taking the freeway back to Devore, we decided it best to take the old highway once again. This time, we made an additional stop at a bridge near Swarthout Canyon Road. This stop proved to be quite interesting as we found the foundations for an old structure that was alongside the 1916 roadway. We figured the old building may have been a gas station or some other roadside service building. We also saw two more trains pass by while we were there.

We headed back to Devore to finish up the tour. By then, we were quite hungry, so we decided to have a late breakfast at Tony’s Diner. The food was decent and the location was nice. It was good to be in a nice air-conditioned building as well. Overall, the tour was a lot of fun, even though it wasn’t well attended. Next time will be better and hopefully be cooler.

Cajon Pass Tour Update

After reviewing the weather forecast for August 12 in the Cajon Pass area, it will be hot. Potentially, a bit over 100 degrees. As such, I am changing the start time of the tour to 8 am instead of 10 am. The start location is still the same in Devore, CA. I know that is a bit of a change, but an earlier start will help with the heat. I strongly recommend bringing water and a hat. If it gets hotter, I may postpone the tour until a later date, most likely September 9.

If anyone has questions about the tour or is interested in attending, please let me know. Thank you and I hope to see you out there!