Quake Watch 2011

Okay - which one of you Folks called on all the Super's to go - don't say that sort of thing

Magnitude 3.1
Date-Time Thursday, March 03, 2011 at 00:29:01 UTC
Wednesday, March 02, 2011 at 04:29:01 PM at epicenter

Location 37.400°N, 118.376°W
Depth 13.7 km (8.5 miles)
Region CENTRAL CALIFORNIA
Distances 4 km (3 miles) NNE (23°) from Bishop, CA
8 km (5 miles) NE (56°) from West Bishop, CA
14 km (9 miles) N (4°) from Wilkerson, CA
59 km (37 miles) ESE (116°) from Mammoth Lakes, CA
300 km (186 miles) ESE (114°) from Sacramento, CA

Location Uncertainty horizontal +/- 0.3 km (0.2 miles); depth +/- 0.7 km (0.4 miles)
Parameters Nph= 37, Dmin=6 km, Rmss=0.06 sec, Gp=108°,
M-type=local magnitude (ML), Version=2
Source California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR

Event ID nc71531765

Magnitude
3.8
Date-Time
Thursday, March 03, 2011 at 02:58:17 UTC
Wednesday, March 02, 2011 at 06:58:17 PM at epicenter
Location
37.399°N, 118.375°W
Depth
14 km (8.7 miles)
Region
CENTRAL CALIFORNIA
Distances
4 km (3 miles) NNE (25°) from Bishop, CA
8 km (5 miles) ENE (57°) from West Bishop, CA
14 km (9 miles) N (4°) from Wilkerson, CA
60 km (37 miles) ESE (116°) from Mammoth Lakes, CA
300 km (186 miles) ESE (114°) from Sacramento, CA
Location Uncertainty
horizontal +/- 0.3 km (0.2 miles); depth +/- 0.6 km (0.4 miles)
Parameters
Nph= 39, Dmin=6 km, Rmss=0.07 sec, Gp=108°,
M-type=local magnitude (ML), Version=2
Source
California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR
Event ID
nc71531805


bigger one!

reply to post by berkeleygal


Hey yours is bigger than mine :-)

Hmmm - almost same exact depth and location - almost

I know it is a smaller one, but that region always makes me nervous.

This event has been reviewed by a seismologist.
Magnitude 4.0
Date-Time Thursday, March 03, 2011 at 03:55:05 UTC
Wednesday, March 02, 2011 at 07:55:05 PM at epicenter
Time of Earthquake in other Time Zones

Location 50.417°N, 129.914°W
Depth 10 km (6.2 miles)
Region VANCOUVER ISLAND, CANADA REGION


earthquake.usgs.gov...

reply to post by MoorfNZ


Yes very interesting. Also interesting to see more use of energy as a measure.


reply to post by muzzy

In laymans terms I think cm/sec means how far the ground moved in one second. Being in the building industry I'm used to using millimeters, so when I seen 70cm I didn't think too much of it, but thats 700mm or close to 3/4 metre, no wonder all those buildings fell down in Christchurch!

I had loads typed up about this and it suddenly decided to dump my text so I am afraid you get the short version now, especially since I started surrounding your quote with [quake] tags! [/quake]

OK, as I understand it this is a measure of the acceleration, but I may be wrong, rather than the actual distance moved. Think of it like the difference between braking slowly in a car and doing an emergency stop.

Yes intensity and ground motion are particularly affected by topography and geology and earthquake depth.


Example of topography/geology differences: This is a map of Arkansas - 4.1
[atsimg]http://files.abovetopsecret.com/images/member/ab4640708c06.jpg[/atsimg]

And this is a 4.5 in Northern California
[atsimg]http://files.abovetopsecret.com/images/member/120d323e47c4.jpg[/atsimg]

And this is a deep 4.7 in the Hindu Kush
[atsimg]http://files.abovetopsecret.com/images/member/351b657cfe2b.jpg[/atsimg]

reply to post by PuterMan

Yes the depth has a lot to do with it, and the Peak Ground Velocity ties in with Magnitude and Modified Mercalli Intensity closely, but not always ( that I have seen from NZ quakes).
Problem with PGV is not all USGS reported events have the PGV so its hard to use it consistantly.
I'm interested in this because of the Global 7=+ project, going back before Richter scale a lot of the quakes were reported in Intensity not Magnitude.
Just tryng to get some idea what to look for so I can include of discard particular quakes from the lists and maps.
At the end of the day I'm probably going over the same stuff someone else has already done and may have to just use what IISEE have already done.

PGV (Peak Ground Velocity) (cm/sec) is different than PGA (Peak Ground Acceleration) which is given in % of G force.
I've started putting the PGV on the popup tags on my Interactive NZ Quake maps where I could get the info off Geonet, they only have PGV available on quakes in the Recent Quakes pages. Even if there are no Felt Reports for a quake, if it makes the Recent Quakes list then the PGV is available, there have been quite a few during the Lyttelton Aftershocks without Felt reports on the List, perhaps due to power still being out in the eastern suburbs (where the Mag 3 quakes were)

edit: If you look at the Akatarawa quake (below) the PGV was highest closest to the quake but the PGA got higher at the stations further away, ie KIW Kapiti Island (just off our beach) was 1.79818 %G whereas CAW Cannon Point (the oen with the highest PGV) had just 1.38677 %G, so it seems the G forces get higher as the wave accelerates away from the epicenter. makes sense

Felt this one I heard it first, woke me up, then one single strong jolt.
Was on the Akatarawa Fault to the east this time.
We are getting hammered from both sides , yesterdays to the SW .

Interestingly the PGV (Peak Ground Velocity) was quite low given the magnitude
Max. PGV was at Cannon Point 0.63343 cm/sec
www.geonet.org.nz...

Reference Number 3473252
Universal Time March 3 2011 at 13:19
NZ Daylight Time Friday, March 4 2011 at 2:19 am
Latitude, Longitude 41.07°S, 175.10°E
Focal Depth 30 km
Richter magnitude 4.7
Region Wellington
Location
* 10 km north-east of Upper Hutt
* 20 km west of Featherston
* 20 km south-east of Paraparaumu
* 40 km north-east of Wellington

Hey guys look at TA.X40A BHE and BHN

MAP 3.7 2011/03/03 15:55:25 35.241 -92.389 6.6 ARKANSAS
MAP 3.2 2011/03/03 15:31:49 35.266 -92.371 6.0 ARKANSAS


Arkansas waking up this afternoon.

reply to post by crazydaisy

Downgraded to 3.5 at this time.

I was just looking at the PGV (my new obsession ) for that one compared to the 3.5 on Feb 25.
earthquake.usgs.gov...
Although the latest one was deeper, the PGV was higher

3.5, 2011/03/03 15:55:25, 35.241, -92.389, 6.6, ARKANSAS, MAX. PGV 0.6 cm/sec
3.5, 2011/02/25 09:49:01, 35.278, -92.374, 5.9, ARKANSAS, MAX. PGV 0.4 cm/sec

If you look at the maps todays map shows a pattern like a comma, kicking down to the SE, unlike the 25th which looks like a circle. I wonder if this shows a weakness in the crust to the SE.

I'll look at some more ARK quakes and see what the pattern is

edit:, OK heres another earlier one, looks like the PGV is increasing, despite the magnitudes being the same
3.5, 2011/02/16 21:46:17, 35.27, 92.36, 6.6, ArKANSAS, MAX PGV 0.3 cm/sec

this may be significant

edit2:
Overview
mag, location, date, time, lat, long, depth, id, max. pgv cm/sec
3.5, ARKANSAS, Mar 03 2011, 15:55:24 UTC, 35.241, -92.389, 6.6, 030311l, 0.6
3.3, ARKANSAS, Mar 01 2011, 16:03:05 UTC, 35.240, -92.391, 5.0, 030111g, 0.2
3.4, ARKANSAS, Feb 28 2011, 08:46:11 UTC, 35.282, -92.341, 2.5, 022811c, 0.3 ,
3.8, ARKANSAS, Feb 28 2011, 05:18:00 UTC, 35.271, -92.374, 4.2, 022811b, 0.6
4.7, ARKANSAS, Feb 28 2011, 05:00:50 UTC, 35.265, -92.344, 3.8, 022811a, 2.8
3.5, ARKANSAS, Feb 25 2011, 09:49:01 UTC, 35.278, -92.374, 5.9, 022511a, 0.4
3.6, ARKANSAS, Feb 20 2011, 15:15:00 UTC, 35.260, -92.375, 5.2, 022011c, 0.6
3.4, ARKANSAS, Feb 19 2011, 23:04:58 UTC, 35.268, -92.374, 6.7, 021911e, 0.048
4.1, ARKANSAS, Feb 18 2011, 08:13:35 UTC, 35.271, -92.377, 6.3, 1182, 2.5
3.9, ARKANSAS, Feb 18 2011, 04:59:50 UTC, 35.257, -92.370, 5.1, 021811a, 1.0
3.8, ARKANSAS, Feb 17 2011, 10:49:48 UTC, 35.276, -92.361, 6.5, 021711b, 1.5
3.5, ARKANSAS, Feb 16 2011, 21:46:17 UTC, 35.270, -92.361, 6.6, 021611o, 0.3

yes the PGV is increasing even if the magnitudes are less, see that last one (at the top) has the same ground velocity reading as previous 3.6 and 3.8 mags

maybe they were a bit hasty downgrading the mag from 3.7

reply to post by muzzy


Muzzy, odd you know - we have folks at ground zero reporting this quakes on the Arkansas Thread. They have been reporting that the ground underthem is just rolling. Gee was looking really funky today. unfortunately, I had closings outside the office all afternoon and was unable to watch to long. The instruments were all over the place coupled with double and triple quakes and a constant rolling being felt. Maybe Westcoast has taken some screenshots.

the ground is quivering right now - almost constant

Well, this is a wierd one. I had to look at the map of the world because I had NO idea where it was.

Pretty much the TOP!

Magnitude 4.8
Date-Time Friday, March 04, 2011 at 02:33:41 UTC
Friday, March 04, 2011 at 08:33:41 AM at epicenter

Location 85.637°N, 84.844°E
Depth 10.1 km (6.3 miles) set by location program
Region NORTH OF SEVERNAYA ZEMLYA
Distances 1813 km (1127 miles) N (359°) from Noril'sk, Russia
3048 km (1894 miles) N (9°) from REYKJAVIK, Iceland

Location Uncertainty horizontal +/- 17.6 km (10.9 miles); depth fixed by location program
Parameters NST=146, Nph=156, Dmin=>999 km, Rmss=0.75 sec, Gp= 47°,
M-type=body wave magnitude (Mb), Version=8
Source U.S. Geological Survey, National Earthquake Information Center:
World Data Center for Seismology, Denver

Event ID usb0001pbl

reply to post by muzzy


Okay, I just got caught up on the conversation over here. I have been hanging out on the Arkansas thread and I find it VERY interesting how they tie into together.

I noticed throughout the day today that the people 'on the ground' were reporting quakes felt much more often than before. They are saying that the ground felt as if it were constantly moving for awhile earlier, and saying they were feeling them, when some barely even showed up on GEE.

I was speculating that perhaps they were getting shallower? I could tell though that something was different.

SO....now I come over here to report the top of the world quake and see your comments about the Peak volocity increasing. Whatever that might mean, I think the people there are feeling that change. Smaller quakes feel stronger and the ground seems to be in greater motion. Is the liquifaction coming into play here now? I hope we don't start seeing sand geysers.

reply to post by westcoast


I had to look at the map too!

Did Santa Fart?

[atsimg]http://files.abovetopsecret.com/images/member/5fc13d43ee55.jpg[/atsimg]

Originally posted by Anmarie96
reply to post by muzzy

 

Muzzy, odd you know - we have folks at ground zero reporting this quakes on the Arkansas Thread. They have been reporting that the ground underthem is just rolling. Gee was looking really funky today. unfortunately, I had closings outside the office all afternoon and was unable to watch to long. The instruments were all over the place coupled with double and triple quakes and a constant rolling being felt. Maybe Westcoast has taken some screenshots.

the ground is quivering right now - almost constant

edit on 3-3-2011 by Anmarie96 because: (no reason given)

Just saw your post. You betchya! Here are some screen shots:

reply to post by westcoast


You know Westcoast, I was think liquifracton myself. Or a early form of it if that makes sense? There must me many contributor's in order to make the earth become as liquid. And, I am sure all that water they are pumping in - only what 15 percent +/- comes back out - may very well be the a cause - back to the microseism

reply to post by westcoast


It probably has to do more with:

1) location of stations relative to quakes- both of those two stations are far enough from the quakes, there could be some local activity strong enough to feel, yet not strong enough to really show up much 40 to 50 miles away at the two TA stations. And some of those quakes look like they were more like 60 to 80 miles away. Because of:

2) where this is happening- remember things change over in this part of the country where seismic waves can propagate up to ten times further than on the west coast. So smaller magnitude local events can make it into the "I felt it" range at lower magnitudes than on the west coast. Especially when you're within 5 miles of the epicenter of a shallow event, in Arkansas.

PGV merely expresses the peak of the first integration of the acceleration record. Accepted formulae now link PGV with MM Intensity. Note that the effect of soft soils gets built into the process, since one can expect that these foundation conditions will amplify the PGV significantly.

emphasis mine.

en.wikipedia.org...

reply to post by TrueAmerican


Odd, we are talking a shale area = hence the dreaded fracking - and then old sand blows = could that be old ground up shale. Then injected water which stays there. BUT. You say soft ground - as just stated but the last large quake in the area in 1811 dropped stepples of churches in MA. And last year a quake hit Canada a good far away from me here in New York and it was like a tracker trailer hitting speed bumps in front of my office. The ground here on the eastern US are much differant then the westcoast. Something amiss here

Here's some new activity around Lassen Peak

This one happened about a half hour ago - still a ?

This is a computer-generated message -- this event has not yet been reviewed by a seismologist.
Magnitude
? (uncertain or not yet determined)
Date-Time
Friday, March 04, 2011 at 04:06:57 UTC
Thursday, March 03, 2011 at 08:06:57 PM at epicenter
Location
40.297°N, 121.008°W
Depth
0.7 km (~0.4 mile) (poorly constrained)
Region
NORTHERN CALIFORNIA
Distances
1 km (1 miles) SSW (201°) from Westwood, CA
8 km (5 miles) ENE (71°) from Hamilton Branch, CA
8 km (5 miles) NE (45°) from East Shore, CA
33 km (21 miles) WSW (246°) from Susanville, CA
198 km (123 miles) N (11°) from Sacramento, CA
Location Uncertainty
horizontal +/- 0.6 km (0.4 miles); depth +/- 2.8 km (1.7 miles)
Parameters
Nph= 23, Dmin=76 km, Rmss=0.16 sec, Gp=169°,
M-type="Nuttli" surface wave magnitude (mbLg), Version=0
Source
California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR
Event ID
nc71537541

This one happened just minutes before

Magnitude
2.9
Date-Time
Friday, March 04, 2011 at 04:06:51 UTC
Thursday, March 03, 2011 at 08:06:51 PM at epicenter
Time of Earthquake in other Time Zones
Location
40.288°N, 121.015°W
Depth
0 km (~0 mile) (poorly constrained)
Region
NORTHERN CALIFORNIA
Distances
2 km (1 miles) SSW (208°) from Westwood, CA
7 km (4 miles) ENE (77°) from Hamilton Branch, CA
7 km (4 miles) NE (46°) from East Shore, CA
34 km (21 miles) WSW (246°) from Susanville, CA
197 km (122 miles) N (11°) from Sacramento, CA
Location Uncertainty
horizontal +/- 0.6 km (0.4 miles); depth +/- 2.2 km (1.4 miles)
Parameters
Nph= 20, Dmin=29 km, Rmss=0.14 sec, Gp=180°,
M-type=duration magnitude (Md), Version=0
Source
California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR
Event ID
nc71537546



? 2011/03/04 04:06:57 40.297 -121.008 0.7 1 km ( 1 mi) SSW of Westwood, CA
2.9 2011/03/04 04:06:51 40.288 -121.015 0.0 2 km ( 1 mi) SSW of Westwood, CA
1.1 2011/03/02 17:53:13 39.690 -120.618 13.3 7 km ( 4 mi) SW of Valley Ranch, CA
1.4 2011/02/25 19:55:01 40.295 -121.026 3.9 2 km ( 1 mi) WSW of Westwood, CA

earthquake.usgs.gov...


Lassen Peak
en.wikipedia.org...

Lassen Peak has the distinction of being the only volcano in the Cascades other than Mount St. Helens to erupt during the 20th century. On May 22, 1915, a powerful explosive eruption at Lassen Peak devastated nearby areas, and it rained volcanic ash as far away as 200 miles (320 km) to the east.[5] This explosion was the most powerful one in a series of eruptions during 1914 through 1917. These were the last eruptions in the Cascade Mountains that occurred before the explosion of Mount St. Helens in the State of Washington. Lassen Volcanic National Park was created in Shasta County, Calif., in order to preserve the devastated areas as they were - for future observation and study - and also to preserve the nearby volcanic features.

Just a thought,did someone look at the Magnetosphere etc. at the Time the Quake hit on the N.-Pole?