12/27/2015 — Volcanic Earthquakes — Southern California Volcanoes struck by noteworthy M4.3 (M4.2) earthquake

A magnitude 4.3 (M4.2 revised) earthquake has struck Southern California directly next to two dormant Volcanoes.

4.2 m earthquake california volcanoes dec 27 2015



The two nearby ancient (long dormant) volcanoes in question are named “Black Mountain” and “Opal Mountain“.   Coordinates of the Earthquake fall directly next to the weathered lava flows still seen in the deserts of Southern California.

The location in question is approximately 90 miles Northeast of downtown Los Angeles, CA.

dormant volcanoes black mountain and Opal Mountain california dec 27 2015


Not much information exists online regarding these two volcanoes – however a BLM (bureau of land management) search on the location turns up this:


“Location: San Bernardino County; 13 miles northwest of Barstow, California (Note: Boundary set backs from roads or trails are 30 to 300 feet) 

Area Description: 20,548 acres. The Black Mountain Wilderness is a volcanic flow and mesa with a deposit of fine grained dune sand in the southeast corner. Elevations range from 2,080 to 3,941 feet at the summit of Black Mountain. Golden eagles and prairie falcons have been seen foraging in this area, which is also known for its occasional display of spring flowers.”


A harder to find USGS paper exists regarding Opal Mountain volcano + lava flow:





This Southern California volcanic earthquake activity was preceded this week by multiple other M4.0+ earthquakes at several ancient volcanoes such as Steamboat Springs volcanic field, Mono Lake Supervolcano / Inyo Craters, Bitner Butte Volcano, and Clear Lake Volcano.

All the aforementioned locations struck by at least M4.0 or greater events — all within a few days time.

west coast volcanoes nevada moving dec 24 2015
Above: December 24, 2015 – At least three long dormant volcanoes were struck by noteworthy earthquakes along the California Nevada border, the buildup at the dormant volcanoes now becoming obvious as another volcanic field has been hit in Southern California.


This recent California Earthquake activity striking at the dormant volcanoes is no shock to those of us who were paying attention LAST WEEK.

Last week, a full earthquake forecast was issued for the West coast of the United States.  The forecast called for a new flurry of M4.0+ earthquake activity to strike along the California / Nevada border at the dormant volcanoes.

See the forecast video which called for the movement here:


Just as expected, a flurry of M4.0+ earthquakes indeed struck at the dormant volcanoes located along the CA/NV border… also along the Gorda Escarpment off shore of NW California.

The area from the Gorda Escarpment, Eastward to the California / Nevada border, and South to Southern California was the area warned for M4.0+ activity.

As you can see in the graphic below…. which shows the past 7 days of earthquakes….. the area which was warned in the above video has now been struck.

area warned vs area hit dec 27 2015


Information on this Earthquake from the USGS:


Magnitude 4.3 mw
Location/uncertainty 35.215°N 117.280°W± 0.2 km
Depth/uncertainty 0.7 km± 0.5
Origin Time
Number of Stations 91
Number of Phases 87
Minimum Distance 21.21 km (0.19°)
Travel Time Residual 0.15 sec
Azimuthal Gap 28°
FE Region Southern California (39)