Category Archives: Geology

Mt Wilson Observatory Geology Talk

Lectures

On Saturday, June 16, at 5:30 pm Mount Wilson Observatory will be hosting a talk by Dr. Tanya Atwater, professor emeritus of geology at UC Santa Barbara. Dr. Atwater played a major role in piecing together the plate tectonic history of our part of the planet. She will talk about how the motions of the Earth’s crust created the current topography of southern California (including the perfect site for astronomers to explore the Universe). The talk will be followed by a rare chance to look look through Mount Wilson Observatory’s 60-inch Telescope, which revolutionized telescope design and allowed astronomer Harlow Shapley to find our place in the Milky Way Galaxy. Tickets are only $20 and proceeds will all go to the maintain the Observatory.

New Post Coming Soon – Imperial Fault and the infrastructure it crosses

I am working on a new post that will discuss the Imperial Fault in the Imperial Valley and how it crosses and interacts with the infrastructure in the area. I recently went on a trip that way to check it out in person and had a lot of fun. Look for the post in the next couple weeks.

Featured Image – 2/27/2018

Irrigation canal offset by the Imperial Fault on Chick Road just west of Barbara Worth Road in the Imperial Valley.

Featured Image – 12/4/2017

Springs and a marshy area long the Northern Death Valley Fault Zone near the Grapevine Ranger Station in Death Valley, CA.

August 12, 2017 Cajon Pass Highway Tour – Updated

South end of Blue Cut showing fire damage.

On August 12, 2017, I will be hosting this websites first highway tour in the Cajon Pass area. This tour will cover the roadway from Verdemont to Cajon Summit. Some portions will have to be skipped, unfortunately, due to fire-related closures. The start of the tour has changed from the initial announcement. It will now begin at Devore, in front of Tony’s Diner at 18291 Cajon Blvd, San Bernardino, CA 92407 at 8 am. Please do not park in their parking lot. There is plenty of on-street and off-street parking in the area.

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After a brief introduction, we plan to leave at about 8:30 am. The tour will stop at the following locations:

  • Verdemont (backtrack)
  • Cajon Blvd (at the freeway)
  • Kenwood Ave
  • Keenbrook
  • Blue Cut
  • Debris Cone Creek
  • Cajon Junction
  • Cajon Summit

Additional stops may be added if needed. I strongly recommend bringing water and snacks as there are few water/food stops along the route. Please RSVP if you plan to attend this tour. Again, we will be leaving the starting point no later than 8:30 am. Please RSVP no later than August 11 so that I can get a rough number of how many will attend. I look forward to seeing you out there!

Poll results and the first tour

Just north of Kenwood Road looking toward Keenbrook. Burn area is evident near the trees in the distance as well as in the mountains.

After taking a small poll on this site regarding possible highway tours, the results are in. It would seem that the Cajon Pass area was the most popular. As such, it will be the first tour given. Unless conditions warrant otherwise, the first tour will be on August 12, 2017. It will begin at the San Bernardino Metrolink station at 10 am. While a more exact itinerary will be created in the near future, the tour will cover the highway as well as the geology from the train station to Cajon Summit. The tour will be in a caravan style with specific stopping points. There may be some short hikes as well to see old pavement, alignments, or bridges. There will also be no cost for the tour. Please RSVP as soon as you can so I can get an idea of how many may show. It should be a lot of fun and I hope to see you out there!

USGS Earthquake Swarms Information

There appears to be the beginnings of a small swarm of earthquakes in the Brawley Seismic Zone, this time in the town of Brawley, California. The USGS has a great website on swarms and why they occur.

http://www.scsn.org/index.php/earthquakes/earthquake-swarms/index.html

Image of the Week – 12/4/2016

Different levels of erosion in Golden Canyon in Death Valley, CA. These changes in level most likely are resultant from earthquakes and uplift of the mountain block.
Different levels of erosion in Golden Canyon in Death Valley, CA. These changes in level most likely are resultant from earthquakes and uplift of the mountain block.

USGS Topographical Maps – Online

All of the topographical maps from USGS are online and easily accessible. Visit TopoView on the USGS site for more details and the maps.

http://ngmdb.usgs.gov/maps/topoview/

M5.1 Borrego Springs Earthquake

intensity

http://earthquake.usgs.gov/earthquakes/eventpage/ci37374687#general