Magnitude 4.9 and 4.7 quakes near Coso Junction, California

Last updated: 2018-03-26 17:50:59 UTC

The Anza group at the University of California San Diego operates a broadband seismograph network consisting of 13 (+ 2) three component broadband seismograph stations centered near Anza Californa (see map).

On Tuesday, July 17th, 2001 at 05:07:25 and 05:59:58 (PDT) we recorded 2 earthquakes (preliminary ml 4.9 and 4.7 respectively ) located ~6km SE of Coso Junction, CA (48km NNW of Ridgecrest). There have been a number of aftershocks recorded by our network.

If you felt the quake, USGS would like to know. Add to the USGS "Did you feel it?" page.

Note that the local map you can link to below will not show this event and its aftershocks as it is just beyond the boundaries of events we plot.

View the most recent map of local events near San Diego or a map of events recoded by ANZA from around the globe. We also have a bulletin of recent events recorded by the Anza network.

Initial source parameters for the recent event and aftershocks are shown below. The epicentral distance (distance separating the epicenter and the recording network) for ANZA is 2.490 degrees.

This map shows the mainshock (red circle). ANZA network stations are blue triangles, KNET network stations are pink triangles. Backgound seismicity is also plotted.




Origin Time




36.0100 -117.890 33.0 7/17/2001 (198) 12:59:58.000 0.0 4.7* SCEC

*note that the location and magnitude determined for this event is preliminary and is subject to change upon further review of seismic data.

You may also view a plot showing the:

Download data: css3.0 miniSEED data for ANZA

Of local interest:
We operate a broadband station on Mt. Soledad. At 06:00:51 (PDT) station SOL recorded the P wave from this event.

Here is a view of that event as picked by our analyst. The pink "P" indicates a P wave arrival, the "S" indicates an S wave arrival.

View a larger image showing the waveforms recorded at Mt. Soledad.

Learn more about the Anza group (including who works here, station information, research, other networks, nuclear tests in China/ India/ Pakistan).

Learn more about the ANZA network (includes more station information, research, etc).

URL: [Last updated: 2018-03-26 17:50:59 UTC]