Recent Status Report, Updates, and Information Releases

LONG VALLEY OBSERVATORY DAILY UPDATEFriday, November 6, 2009 9:12 AM PST (Friday, November 6, 2009 17:12 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located eight small earthquakes in the vicinity of Long Valley caldera since the last update at 9:17 AM (PST) on November 5. Four were located in the south moat of the caldera beneath the west end of the airport (6 miles east of Mammoth Lakes). They occurred between 3:26 PM and 4:56 PM on the 5th. The largest was the magnitude M=1.1 earthquake at 4:56 PM. The remaining four were located in the Sierra Nevada south of the caldera. The larges of these was a M=1.0 earthquake at 3:35 PM on the 5th located 11 miles SW of Tom's Place.

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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 DAILY UPDATEThursday, November 5, 2009 9:17 AM PST (Thursday, November 5, 2009 17:17 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The only earthquake in the general vicinity of Long Valley caldera located by the real-time computer system since the last update at 9:12 AM (PST) on November 4 was a M=2.0 event at 6:41 PM on the 4th centered 4 miles SSE of Bishop.

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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 DAILY UPDATEWednesday, November 4, 2009 9:12 AM PST (Wednesday, November 4, 2009 17:12 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located no earthquakes in the Long Valley caldera area since the last update at 8:55 AM (PST) on November 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 DAILY UPDATETuesday, November 3, 2009 8:55 AM PST (Tuesday, November 3, 2009 16:55 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located one small earthquake in the Long Valley caldera area since the last update at 8:27 AM (PST) on November 2. This was a magnitude M=1.3 earthquake at 1:12 PM on the 2nd located beneath Mammoth Mountain (4 miles west 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 DAILY UPDATEMonday, November 2, 2009 8:27 AM PST (Monday, November 2, 2009 16:27 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located one small earthquake in the Long Valley caldera area since the last update at 8:54 AM (PST) on November 1. This was a magnitude M=1.4 earthquake at 4:50 PM on the 1st located in the Sierra Nevada south of the caldera (7 miles WSW of Tom's Place).

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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 DAILY UPDATESunday, November 1, 2009 8:54 AM PST (Sunday, November 1, 2009 16:54 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located three small earthquake in the Long Valley caldera area since the last update at 10:48 AM on October 31. Magnitude M=2.3 and 1.6 earthquakes at 12:33 and 2:15 PM on the 31st, respectively, were located 2 miles east of Tom's Place (midway between Tom's Place and the Owens River gorge). A M=0.9 earthquake at 2:29 PM was located beneath the east flank of McGee Mountain at the southern margin of the caldera (8 miles west of Tom's Place).
Elsewhere, a M=1.7 earthquake at 5:57 PM on the 31st was located 7 miles NE of Bridgeport, and a M=1.9 earthquake at 3:26 AM on November 1 was located 3 miles south of Big Pine.

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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 DAILY UPDATESaturday, October 31, 2009 10:48 AM PDT (Saturday, October 31, 2009 17:48 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located six small earthquake in the Long Valley caldera area since the last update at 9:27 AM on October 30. A M=3.2 earthquake at 9:37 AM on the 30th occurred beneath Mt. Huntington at the SE margin of Pioneer Basin (9 miles SW of Ton's Place) followed by a M=0.9 aftershock at 2:20 PM. Of two smaller earthquakes in general vicinity of the Sierra Nevada, the largest was a M=1.6 event at 11:23 located 8 miles west of Tom's Place. A pair of earthquakes with magnitudes M=1.0 and 1.4 at 12:59 and 1:01 PM on the 30th was located beneath the west margin of Chalfant Valley (12 miles ENE of Tom's Place)-- the same area as the M=2.6 earthquake at 8:40 AM on the 30th.

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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 DAILY UPDATEFriday, October 30, 2009 9:27 AM PDT (Friday, October 30, 2009 16:27 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located nine small earthquake in the Long Valley caldera area since the last update at 9:21 AM on October 29. Eight were located in the Sierra Nevada south of the Caldera including a cluster of four earthquakes between 3:58 and 4:08 PM on the 29th located just east of Lake Genevieve (8 miles SE of Mammoth Lakes). The largest of these was the M=0.7 event at 4:08 PM. A M=1.1 earthquake in the same area followed at 8:30 PM. The largest earthquake in the region was a M=2.6 earthquake at 8:40 AM on the 30th located beneath the west margin of Chalfant Valley (12 miles ENE of Tom's Place).

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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 DAILY UPDATEThursday, October 29, 2009 9:21 AM PDT (Thursday, October 29, 2009 16:21 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located three small earthquake in the Long Valley caldera area since the last update at 9:08 AM on October 28. Two were located in the Sierra Nevada south of the caldera. The largest was a M=1.3 earthquake at 3:50 PM on the 28th located 11 miles SW of Tom's Place. A M=1.9 earthquake at 12:27 AM on the 29th was located beneath the southern margin of the caldera two miles west of Crowley Lake (7 miles north of Tom's Place).

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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 DAILY UPDATEWednesday, October 28, 2009 9:08 AM PDT (Wednesday, October 28, 2009 16:08 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 11122 ft (3390 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The real-time computer system located five small earthquake in the Long Valley caldera area since the last update at 9:04 AM on October 27. All were located in the Sierra Nevada south of the caldera. The largest was a M=1.2 earthquake at 10:17 PM on the 27th located 11 miles SW of Tom's Place.

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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 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: Thursday, 01-Oct-2009 10:11:07 (dyv)