What's Going on at Long Valley?

This is not quieting down, at all.

Since my last update:
2.8 2010/07/21 04:52:05 37.620 -118.814 7.4 13 km ( 8 mi) WNW of Toms Place, CA
1.4 2010/07/21 04:03:20 37.623 -118.817 7.7 14 km ( 9 mi) WNW of Toms Place, CA
2.0 2010/07/20 23:39:47 37.575 -118.843 3.3 14 km ( 9 mi) ESE of Mammoth Lakes, CA
2.1 2010/07/20 20:56:11 37.623 -118.817 8.0 14 km ( 9 mi) WNW of Toms Place, CA
1.2 2010/07/20 17:29:29 37.623 -118.815 8.3 14 km ( 9 mi) WNW of Toms Place, CA

Magnitude 2.5 - LONG VALLEY AREA, CALIFORNIA
2010 July 21 12:23:21 UTC

* Details
* Maps
* Scientific & Technical

Earthquake Details

* This is a computer-generated message -- this event has not yet been reviewed by a seismologist.

Magnitude 2.5
Date-Time

* Wednesday, July 21, 2010 at 12:23:21 UTC
* Wednesday, July 21, 2010 at 05:23:21 AM at epicenter
* Time of Earthquake in other Time Zones

Location 37.624°N, 118.816°W
Depth 8 km (5.0 miles)
Region LONG VALLEY AREA, CALIFORNIA
Distances 15 km (10 miles) ESE of Mammoth Lakes, California
45 km (30 miles) NW of Bishop, California
80 km (50 miles) SSE of Bridgeport, California
260 km (160 miles) ESE of SACRAMENTO, California
Location Uncertainty horizontal +/- 0.2 km (0.1 miles); depth +/- 0.5 km (0.3 miles)
Parameters Nph= 36, Dmin=4 km, Rmss=0.05 sec, Gp= 40°,
M-type=duration magnitude (Md), Version=1
Source

* California Integrated Seismic Net:
* USGS Caltech CGS UCB UCSD UNR

Event ID nc71429110

Since that 2.5 in the last post:

2.0 2010/07/22 03:01:47 37.620 -118.814 7.5 13 km ( 8 mi) WNW of Toms Place, CA
1.9 2010/07/21 22:23:27 37.623 -118.816 8.3 14 km ( 9 mi) WNW of Toms Place, CA
1.6 2010/07/21 22:21:52 37.622 -118.815 7.7 14 km ( 8 mi) WNW of Toms Place, CA
1.6 2010/07/21 18:12:04 37.624 -118.815 8.1 14 km ( 9 mi) WNW of Toms Place, CA

Same old depth, same old location.

Things are looking a little interesting

1.3 2010/07/22 04:52:03 37.627N 118.817W 7.5 14 km ( 9 mi) WNW of Toms Place, CA
1.4 2010/07/22 04:49:01 37.625N 118.819W 7.6 14 km ( 9 mi) WNW of Toms Place, CA
1.2 2010/07/22 04:44:50 37.628N 118.814W 8.2 14 km ( 9 mi) WNW of Toms Place, CA
1.3 2010/07/22 04:44:34 37.627N 118.818W 8.1 14 km ( 9 mi) WNW of Toms Place, CA
1.1 2010/07/22 04:43:52 37.622N 118.817W 7.9 14 km ( 9 mi) WNW of Toms Place, CA
3.8 2010/07/22 04:40:08 37.624N 118.815W 8.4 14 km ( 9 mi) WNW of Toms Place, CA

I and my wife were in the Long Valley Region on the 19th. To look at the caldera's atop those ominous peaks is a very humbling experience - I'm glad nothing happened while we were there lol...!

I did however discover an ancient indian point chipping grounds near the Long Valley obsidian flow off of 395 lol... brought home a sack full of obsidian flakes!! some of which were of obsidians from flows both in the Northern California pumice flow, and Bend, Oregon (infamous fire obsidian), outside of the Long Valley obsidian flow, which is pure black, with some snowflaking in northern quadrant.

I think the best views of the Long Valley Caldera System can be found at Convict Lake!!

Magnitude 3.8


oops beaten to it!

[edit on 22-7-2010 by MoorfNZ]

Magnitude 2.6
Date-Time

* Thursday, July 22, 2010 at 13:03:42 UTC
* Thursday, July 22, 2010 at 06:03:42 AM at epicenter

Location 37.623°N, 118.814°W
Depth 8.4 km (5.2 miles)
Region LONG VALLEY AREA, CALIFORNIA
Distances

* 14 km (8 miles) WNW (300°) from Toms Place, CA
* 15 km (9 miles) E (96°) from Mammoth Lakes, CA
* 30 km (19 miles) NW (321°) from Round Valley, CA
* 254 km (158 miles) ESE (113°) from Sacramento, CA

That 3.8 is the largest so far.

Complete list since my last post, more evidence for my theory that volcanoes will only do interesting things while I am sleeping.

MAP 1.3 2010/07/22 15:07:29 37.630 -118.820 7.9 14 km ( 9 mi) E of Mammoth Lakes, CA
MAP 1.1 2010/07/22 14:10:26 37.623 -118.816 7.5 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.0 2010/07/22 13:56:03 37.625 -118.812 7.7 14 km ( 8 mi) WNW of Toms Place, CA
MAP 2.6 2010/07/22 13:03:42 37.623 -118.814 8.4 14 km ( 8 mi) WNW of Toms Place, CA
MAP 1.2 2010/07/22 12:18:28 37.625 -118.817 7.6 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.3 2010/07/22 12:14:19 37.628 -118.814 7.3 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.3 2010/07/22 12:02:05 37.624 -118.819 7.2 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.3 2010/07/22 11:57:55 37.631 -118.819 7.7 14 km ( 9 mi) E of Mammoth Lakes, CA
MAP 1.0 2010/07/22 11:56:31 37.626 -118.818 7.2 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.7 2010/07/22 11:55:21 37.622 -118.812 8.1 13 km ( 8 mi) WNW of Toms Place, CA
MAP 1.3 2010/07/22 11:52:03 37.627 -118.817 7.5 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.4 2010/07/22 11:49:01 37.625 -118.819 7.6 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.2 2010/07/22 11:44:50 37.628 -118.814 8.2 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.3 2010/07/22 11:44:34 37.627 -118.818 8.1 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.1 2010/07/22 11:43:52 37.622 -118.817 7.9 14 km ( 9 mi) WNW of Toms Place, CA
MAP 3.8 2010/07/22 11:40:08 37.624 -118.815 8.4 14 km ( 9 mi) WNW of Toms Place, CA
MAP 1.1 2010/07/22 05:16:19 37.528 -118.823 3.9 13 km ( 8 mi) WSW of Toms Place, CA
MAP 1.2 2010/07/22 04:15:28 37.624 -118.812 7.6 14 km ( 8 mi) WNW of Toms Place, CA
MAP 1.8 2010/07/22 03:55:06 37.623 -118.817 7.8 14 km ( 9 mi) WNW of Toms Place, CA

Long Valley updates lately have been one paragraph with no mention of deformation, hydrology or gas. I've been finding this frustrating. Looking forward to an official update tomorrow, but it will probably just be another paragraph summarizing what anyone can see from looking at the earthquake lists.

reply to post by quakewatcher


I think we may get more out of the than the one paragraph. I am quiet surprised (well, not really) that They haven't given a special statement as there is a swarm happening. As far as deformation etc. If you follow the links and the links on the left Here under Monitoring Data, you can see that there is definitely something going on.

Well, Here you go - Them at Their Finest - shall we pick the update apart?

Long Valley Observatory Recent Status Report, Updates, and Information Releases
LONG VALLEY OBSERVATORY WEEKLY UPDATE
Friday, July 23, 2010 10:53 AM PDT (Friday, July 23, 2010 17:53 UTC)


LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 7231 ft (2204 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Activity in the Long Valley caldera region this last week was dominated by a sequence of small earthquakes centered beneath the southern margin of the caldera 2 miles east of the airport. To date, the sequence has included 58 earthquakes with magnitudes M=1.0 or greater and ten with magnitudes M=2.0 or greater. The two largest earthquakes with magnitudes M=3.4 and M=3.8 at 11:16 PM on the 17th and 4:40 AM on the 22nd, respectively, produced perceptible shaking in the Mammoth Lakes area. The initial earthquake in this sequence was the M 2.0 earthquake at 9:54 PM on the 15th noted in last week's update. Data from tilt and strain meters in the area show no evidence for significant ground deformation associated with this sequence, and we see no other evidence indicating that this earthquake sequence is associated with the movement of magma beneath the caldera. Long Valley caldera has produced eight M 3 earthquakes since 2000 including the two during this sequence. This level of activity is considered normal for the area.

At least this week they acknoledged a swarm

The latest update from the USGS - source


LONG VALLEY OBSERVATORY WEEKLY UPDATE
Friday, July 30, 2010 4:38 PM PDT (Friday, July 30, 2010 23:38 UTC)


LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 7231 ft (2204 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

The earthquake swarm that started on July 15 in Long Valley Caldera ~ 9 miles east of the town of Mammoth Lakes continued through the week, although at a subdued level. Only eight earthquakes between magnitude M=1.0 and M=1.8 were recorded. The largest earthquake of the week, a magnitude M=2.6, occurred outside the caldera, in Round Valley. Five other events of magnitude M

Magnitude 3.7 - LONG VALLEY AREA, CALIFORNIA
2010 August 06 01:20:03 UTC

* Details
* Maps
* Scientific & Technical

Earthquake Details

* This event has been reviewed by a seismologist.

Magnitude 3.7
Date-Time

* Friday, August 06, 2010 at 01:20:03 UTC
* Thursday, August 05, 2010 at 06:20:03 PM at epicenter
* Time of Earthquake in other Time Zones

Location 37.622°N, 118.814°W
Depth 7.6 km (4.7 miles)
Region LONG VALLEY AREA, CALIFORNIA
Distances 15 km (10 miles) ESE of Mammoth Lakes, California
45 km (30 miles) NW of Bishop, California
80 km (50 miles) SSE of Bridgeport, California
260 km (160 miles) ESE of SACRAMENTO, California
Location Uncertainty horizontal +/- 0.2 km (0.1 miles); depth +/- 0.4 km (0.2 miles)
Parameters Nph= 41, Dmin=3 km, Rmss=0.05 sec, Gp= 54°,
M-type=local magnitude (ML), Version=3
Source

* California Integrated Seismic Net:
* USGS Caltech CGS UCB UCSD UNR

Event ID nc71442046

Beat me to it, I was just coming over here to post about that. Funny, it's like chatter. One hot spot starts talking and the rest gossip about it.

This one's in the same spot as that swarm that had quieted down in the past week or so.

Originally posted by quakewatcher
Beat me to it, I was just coming over here to post about that. Funny, it's like chatter. One hot spot starts talking and the rest gossip about it.

This one's in the same spot as that swarm that had quieted down in the past week or so.

yes i know which is why i posted it.

and quakewatcher your very welcome .

A 2.1 significantly to the Southeast of the last one.

2.1 2010/08/06 02:00:42 37.560 -118.644 10.5 3 km ( 2 mi) E of Toms Place, CA

Originally posted by quakewatcher
A 2.1 significantly to the Southeast of the last one.

2.1 2010/08/06 02:00:42 37.560 -118.644 10.5 3 km ( 2 mi) E of Toms Place, CA

any clue on how deep the magma chamber is under long valley?

any charts availible that will show volcanic HT tremors ore is it just seismic?

Lets keep in mind that distant large quakes can have a profound effect on Long Valley. Anyone who remember the Landers earthquake? That quake was providing the first clearly documented case of remotely triggered seismicity by a large, distant earthquake.

At Long Valley Caldera, the shear waves from the Landers earthquake also triggered a transient, caldera-wide uplift that reached a peak strain of 0.3 parts per million (ppm) 5 to 6 days after the Landers event.

(Note: the 0.3-ppm peak strain corresponds to a peak uplift of roughly 0.5 cm or 0.2 inches.)

The June 1992 swarm itself included more than 250 located events distributed throughout the SMSZ, the largest of which was M=3.4 earthquake in the west lobe. Triggered seismic activity in the Sierra Nevada block immediately south of the caldera included a M=3.7 earthquake.

So lets keep an eye open for quakes outside the caldera itself also and not limit it to events within the caldera alone.

reply to post by alysha.angel
As far as I know, the magma reservoir is centered at a depth of 7 to 12 km beneath the central section of the resurgent dome.