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CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, October 1, 2018, 10:10 AM PDT (Monday, October 1, 2018, 17:10 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for September 1, 2018 (0000h PST) through September 30, 2018 (2359h PDT):
Mt Shasta: One earthquake at or above M1.0 was detected, registering M1.65.
Medicine Lake: One earthquake at or above M1.0 was detected, registering M1.26.
Lassen Volcanic Center: No earthquakes at or above M1.0 were detected.
Clear Lake Volcanic Field: One earthquake at or above M1.0 was detected, registering M1.52. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.76].
Long Valley Volcanic Region: In Long Valley Caldera, 25 earthquakes of M1.0 or greater were detected, with the largest event registering M2.69. One earthquake at or above M1.0 was detected in the Mono Craters region (M1.36). Four earthquakes at or above M1.0 were detected under Mammoth Mountain. The largest event registered M1.61. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.85].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Five earthquakes of M1.0 or greater were detected, with the largest registering M2.08.
Coso Volcanic Field: Five earthquakes of M1.0 or greater were detected, with the largest registering M1.85.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, September 10, 2018, 10:27 AM PDT (Monday, September 10, 2018, 17:27 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for August 1, 2018 (0000h PST) through August 31, 2018 (2359h PDT):
Mt Shasta: One earthquake at or above M1.0 was detected, registering M1.12.
Medicine Lake: No earthquakes at or above M1.0 were detected.
Lassen Volcanic Center: No earthquakes at or above M1.0 were detected.
Clear Lake Volcanic Field: No earthquakes at or above M1.0 were detected. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.27].
Long Valley Volcanic Region: In Long Valley Caldera, 74 earthquakes of M1.0 or greater were detected, with the largest event registering M2.93. No earthquakes at or above M1.0 were detected in the Mono Craters region. No earthquakes at or above M1.0 were detected under Mammoth Mountain. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.78].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Two earthquakes of M1.0 or greater were detected, with the largest registering M1.71.
Coso Volcanic Field: No earthquakes at or above M1.0 were detected.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, August 6, 2018, 1:39 PM PDT (Monday, August 6, 2018, 20:39 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for July 1, 2018 (0000h PST) through July 31, 2018 (2359h PDT):
Mt Shasta: No earthquakes at or above M1.0 were detected.
Medicine Lake: No earthquakes at or above M1.0 were detected.
Lassen Volcanic Center: No earthquakes at or above M1.0 were detected.
Clear Lake Volcanic Field: No earthquakes at or above M1.0 were detected. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.44].
Long Valley Volcanic Region: In Long Valley Caldera, 59 earthquakes of M1.0 or greater were detected, with the largest event registering M2.98. Two earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest event was M1.67. Ten earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.43. Most of these events occurred during a minor seismic swarm on July 29-31 about three miles southwest of Mammoth Lakes. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.67].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Fifteen earthquakes of M1.0 or greater were detected, with the largest registering M2.71.
Coso Volcanic Field: Sixteen earthquakes of M1.0 or greater were detected. The largest registered M1.64.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, July 2, 2018, 1:48 PM PDT (Monday, July 2, 2018, 20:48 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for June 1, 2018 (0000h PST) through June 30, 2018 (2359h PDT):
Mt Shasta: One earthquake of M1.0 or greater was detected (M1.12).
Medicine Lake: Two earthquakes of M1.0 or greater were detected, with the largest event registering M1.13.
Lassen Volcanic Center: Four earthquakes of M1.0 or greater were detected, with the largest event registering M1.37.
Clear Lake Volcanic Field: No earthquakes at or above M1.0 were detected. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.22].
Long Valley Volcanic Region: In Long Valley Caldera, 44 earthquakes of M1.0 or greater were detected, with the largest event registering M2.61. No earthquakes at or above M1.0 were detected in the Mono Craters region. Two earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.91. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.26].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Four earthquakes of M1.0 or greater were detected, with the largest registering M2.22.
Coso Volcanic Field: Seventeen earthquakes of M1.0 or greater were detected, with the largest registering M1.84.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Friday, June 1, 2018, 11:47 AM PDT (Friday, June 1, 2018, 18:47 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for May 1, 2018 (0000h PST) through May 31, 2018 (2359h PDT):
Mt Shasta: One earthquake of M1.0 or greater was detected (M1.25).
Medicine Lake: One earthquake of M1.0 or greater was detected (M1.32).
Lassen Volcanic Center: Two earthquakes of M1.0 or greater were detected, with the largest event registering M1.39.
Clear Lake Volcanic Field: Three earthquakes of M1.0 or greater were detected, with the largest event registering M1.90. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M4.19].
Long Valley Volcanic Region: In Long Valley Caldera, 30 earthquakes of M1.0 or greater were detected, with the largest event registering M2.19. Four earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest registered M2.96. Three earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.48. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.22].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Twenty-one earthquakes of M1.0 or greater were detected, with the largest registering M2.19.
Coso Volcanic Field: Fifteen earthquakes of M1.0 or greater were detected, with the largest registering M2.03.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Tuesday, May 1, 2018, 10:23 AM PDT (Tuesday, May 1, 2018, 17:23 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for April 1, 2018 (0000h PST) through April 30, 2018 (2359h PDT):
Mt Shasta: One earthquake of M1.0 or greater was detected (M1.61).
Medicine Lake: Five earthquakes of M1.0 or greater were detected, with the largest event registering M1.26.
Lassen Volcanic Center: One earthquake of M1.0 or greater was detected (M1.32).
Clear Lake Volcanic Field: Five earthquakes of M1.0 or greater were detected, with the largest event registering M2.02. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.49].
Long Valley Volcanic Region: In Long Valley Caldera, 53 earthquakes of M1.0 or greater were detected, with the largest event registering M2.57. Six earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest registered M2.28. Six earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.95. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.29].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Two earthquakes of M1.0 or greater were detected, with the largest registering M2.26.
Coso Volcanic Field: Fifteen earthquakes of M1.0 or greater were detected, with the largest registering M2.17.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Monday, April 2, 2018, 11:37 AM PDT (Monday, April 2, 2018, 18:37 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for March 1, 2018 (0000h PST) through March 31, 2018 (2359h PDT):
Mt Shasta: No earthquakes of M1.0 or greater were detected.
Medicine Lake: No earthquakes at or above M1.0 were detected.
Lassen Volcanic Center: Eight earthquakes of M1.0 or greater were detected, with the largest event registering M1.49.
Clear Lake Volcanic Field: One earthquake of M1.0 or greater was detected (M1.52). [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M2.98].
Long Valley Volcanic Region: In Long Valley Caldera, 98 earthquakes of M1.0 or greater were detected, with the largest event registering M2.98. Two earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest registered M2.01. Six earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.98. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.80].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Four earthquakes of M1.0 or greater were detected, with the largest registering M1.76.
Coso Volcanic Field: Nineteen earthquakes of M1.0 or greater were detected, with the largest registering M2.69.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Thursday, March 1, 2018, 10:50 AM PST (Thursday, March 1, 2018, 18:50 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for February 1, 2018 (0000h PST) through February 28, 2018 (2359h PDT):
Mt Shasta: Three earthquakes of M1.0 or greater were detected, with the largest event registering M1.49.
Medicine Lake: No earthquakes of M1.0 or greater were detected.
Lassen Volcanic Center: Thirty-six earthquakes of M1.0 or greater were detected, with the largest event registering M2.87. Many of these events occurred during two minor seismic swarms on February 17 and 19-20, 2018 near the Shasta, Tehama and Plumas county lines and about 8 miles northeast of the town of Mineral.
Clear Lake Volcanic Field: No earthquakes of M1.0 or greater were detected. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M3.23].
Long Valley Volcanic Region: In Long Valley Caldera, 35 earthquakes of M1.0 or greater were detected, with the largest event registering M2.20. Ten earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest registered M2.49. One earthquake of M1.0 or greater was detected under Mammoth Mountain (M1.52). [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.40].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Ten earthquakes of M1.0 or greater were detected, with the largest registering M2.47.
Coso Volcanic Field: Seventeen earthquakes of M1.0 or greater were detected, with the largest registering M2.15.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Thursday, February 1, 2018, 9:37 AM PST (Thursday, February 1, 2018, 17:37 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for January 1, 2018 (0000h PST) through January 31, 2018 (2359h PDT):
Mt Shasta: No earthquakes of M1.0 or greater were detected.
Medicine Lake: No earthquakes of M1.0 or greater were detected.
Lassen Volcanic Center: Three earthquakes of M1.0 or greater were detected, with the largest event registering M1.60.
Clear Lake Volcanic Field: Five earthquakes of M1.0 or greater were detected, with the largest event registering M2.63. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M4.28].
Long Valley Volcanic Region: In Long Valley Caldera, 24 earthquakes of M1.0 or greater were detected, with the largest event registering M2.07. Four earthquakes of M1.0 or greater were detected in the Mono Craters region. The largest registered M1.42. Eight earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M2.23. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M3.09].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Fourteen earthquakes of M1.0 or greater were detected, with the largest registering M2.93.
Coso Volcanic Field: The typical high level of seismicity was observed, with 20 earthquakes M1.0 or greater. The largest registered M2.48.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.


CALIFORNIA VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Thursday, January 4, 2018, 11:36 AM PST (Thursday, January 4, 2018, 19:36 UTC)


Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN


Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.


Observations for December 1, 2017 (0000h PST) through December 31, 2017 (2359h PDT):
Mt Shasta: No earthquakes of M1.0 or greater were detected.
Medicine Lake: Seven earthquakes of M1.0 or greater were detected, with the largest registering M1.88.
Lassen Volcanic Center: One earthquake of M1.0 or greater was detected (M1.31).
Clear Lake Volcanic Field: One earthquake of M1.0 or greater was detected (M1.01). [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M2.35].
Long Valley Volcanic Region: In Long Valley Caldera, 36 earthquakes of M1.0 or greater were detected, with the largest event registering M2.42. No earthquakes of M1.0 or greater were detected in the Mono Craters region. Two earthquakes of M1.0 or greater were detected under Mammoth Mountain, with the largest registering M1.03. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M3.78].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Five earthquakes of M1.0 or greater were detected, with the largest registering M2.48.
Coso Volcanic Field: The typical high level of seismicity was observed, with 11 earthquakes M1.0 or greater. The largest registered M2.90.


The U.S. Geological Survey will continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted. For a definition of alert levels see http://volcanoes.usgs.gov/activity/alertsystem/icons.php.

As part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada. For additional USGS CalVO volcano information, background, images, and other graphics visit http://volcanoes.usgs.gov/observatories/calvo/. For general information on the USGS Volcano Hazard Program http://volcanoes.usgs.gov. Statewide seismic information for California and Nevada can be found at http://earthquake.usgs.gov/earthquakes/recenteqscanv/.