Recent Status Report, Updates, and Information Releases

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Tuesday, May 5, 2009 09:11 PDT (Tuesday, May 5, 2009 16:11 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

The realtime detection system located six small earthquakes in the Long Valley caldera area since the last update at 9:31 AM on May 4. Five were located in the Sierra Nevada south of the caldera (9 to 11 miles SW of Tom's Place), the largest of which was a M=1.9 earthquake at 7:04 AM on the 5th. The sixth was a M=0.5 earthquake beneath the south moat of the caldera (7 miles east of Mammoth Lakes) at 9:09 PM on the 4th.
Elsewhere, a M=1.4 earthquake at 9:39 AM on the 4th was located beneath the east shore of Mono Lake -- in the same area as the series of small earthquakes on May 3.

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The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Monday, May 4, 2009 09:31 PDT (Monday, May 4, 2009 16:31 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

The realtime detection system located no earthquakes in the Long Valley caldera area since the last update at 9:56 AM on May 3.

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The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Sunday, May 3, 2009 09:56 PDT (Sunday, May 3, 2009 16:56 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

The realtime detection system located just one small (M=0.9) earthquake in the Long Valley caldera area since the last update at 9:37 AM on April 1. It occurred at 2:02 PM on the 2nd and was located in the Sierra Nevada 8 miles WSW of Ton's Place.
Elsewhere, earthquakes with magnitudes 1.6, 2.1, and 2.4 occurred beneath the east shore of Mono Lake (10 miles ESE of Lee Vining) at 12:34 AM, 3:65 AM, and 4:41 AM, respectively.

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The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Saturday, May 2, 2009 10:02 PDT (Saturday, May 2, 2009 17:02 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

The realtime detection system located no earthquakes in the Long Valley caldera area since the last update at 9:37 AM on April 1.

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The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Friday, May 1, 2009 09:37 PDT (Friday, May 1, 2009 16:37 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

The realtime detection system located five small earthquakes in the Long Valley caldera area since the last update at 10:57 AM on March 30. Four were located in the Casa Diablo Hot Springs area just east of the 203-395 Hwy junction. The largest was a M=1.6 earthquake at 3:03 PM yesterday (March 30). The other was a M=0.9 earthquake at 12:36 PM located beneath the east moat of the caldera 1 mile north of Big Alkali Lake (11 miles ESE of Mammoth Lakes).

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The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Thursday, April 30, 2009 10:57 PDT (Thursday, April 30, 2009 17:57 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

No earthquakes were located by the Long Valley real-time detection system since the last update at 9:10 AM on April 29.

-----
The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

LONG VALLEY OBSERVATORY CURRENT STATUS REPORT
Wednesday, April 29, 2009 09:10 PDT (Wednesday, April 29, 2009 16:10 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW#1203-14-)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

No earthquakes were located by the Long Valley real-time detection system since the last update at 10:05 AM on April 28.

-----
The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing, and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. There have been multiple smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

Long Term Trends

Seismic Trend: Earthquake activity within and adjacent to the caldera has remained low since mid-1999 averaging just five to ten earthquake per day with magnitudes less than M=2 and an occasional event as large as M=3. see details.

Deformation trend: Renewed uplift of the resurgent dome that began in early 2002 ended in early 2003 largely offsetting the 2 cm of subsidence that accumulated from early 1999 through the end of 2001. The resurent dome has since shown minor fluctuations in uplift and subsidence but remains roughly 80 cm higher than in the late 1970's. see details.

CO₂ trend: The diffuse carbon dioxide gas flux in the Horseshoe Lake tree-kill area has shown little change from the relatively high levels of 50 to 150 tons per day sustained for the past several years; see details.

Update Archive and Quarterly and Annual Summaries | Reference map for place names

For more information about the Volcano Alert Level and Aviation Color Code, please see the USGS Volcanic Activity Alert-Notification System web page.

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Page Last Modified: Tuesday, 18-Nov-2008 13:31:02 (dyv)