Category Archives: USGS

Earthquake Information

Felt an earthquake? Want to know where it was and how big? Follow the links below to get up-to-date information from the USGS and the California Geological Survey.

If you felt the earthquake, let the USGS know by contacting them at: Did You Feel It? This data helps them determine magnitude of the earthquake, how the geology affects that, and how the type of structure reacts to the event. Most earthquakes larger than 4.0 are listed in the “Events”  section of the page.

Additional Earthquake Information:

M 3.5 near Castaic, CA – Updated

This morning (2/21/2020) at 5:42 am, a small earthquake struck the Castaic area north of Los Angeles. Just looking at the maps, it seems near the San Gabriel Fault but it is a somewhat complex area. It was also a very deep earthquake as they go, 18.1 km. Shaking was felt in a wide area but wasn’t very strong.

Shake map for the earthquake. Now a M 3.5.

For more information, check out the USGS Summary Page of the event.

https://earthquake.usgs.gov/earthquakes/eventpage/ci39079535/executive

M 3.6 – 4km NNE of Granada Hills, CA

Shakemap from USGS showing the extent of shaking and major fault lines

On January 21, 2020, just a few days after the 26th anniversary of the Mw 6.7 Northridge Earthquake, we had another small jolt strike the San Fernando Valley. This one, while small, was felt over a wide area. If you are among the many that did feel it, the USGS wants to hear from you! These “Did You Feel It?” reports help them to understand earthquakes further.

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

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/