Quake Watch 2011

Originally posted by Brogue
reply to post by MamaJ

 

This woke me up about an hour ago - it was a good shake..am very much over them.
this makes the 7477th we have had in the last 12 months since our 7.1 on Sept 4 last year

www.geonet.org.nz...
quake.crowe.co.nz...

Eastsider here (Woolston). Yep, I'm sure it woke most everyone!
Another day where everyone will be tired
Wife rang from work (emergency Vet clinic) and said it was the largest she's felt for a while. In my sleepy haze I thought it was around 4ish. I just can't discern anymore, despite all the practice.

Take care.

slightly bigger one offshore to the east of East Cape, south end of Kermadec Trench

Reference Number 3572138
Universal Time September 1 2011 at 18:58
NZ Standard Time Friday, September 2 2011 at 6:58 am
Latitude, Longitude 37.61°S, 179.80°E
Focal Depth 33 km
Richter magnitude 5.053
Region Kermadec Trench
Location

120 km east of Tikitiki
130 km east of Te Araroa
200 km north-east of Gisborne
450 km east of Auckland

www.geonet.org.nz...

reply to post by aorAki


((((((HUGS))))))) My heart goes out to ya'll! I can't imagine....I have tried. Until I am in a Quake I can't know what it feels like. Even then...to constantly be reminded is insanity.

They're partying in PR!

Magnitude
3.0
Date-Time
Thursday, September 01, 2011 at 05:16:13 UTC
Thursday, September 01, 2011 at 01:16:13 AM at epicenter
Time of Earthquake in other Time Zones
Location
17.976°N, 65.464°W
Depth
30.5 km (19.0 miles)
Region
PUERTO RICO REGION
Distances
14 km (8 miles) S (174°) from Esperanza, PR
33 km (21 miles) SSE (147°) from Roosevelt Roads, PR
36 km (22 miles) SE (140°) from Daguao, PR
70 km (43 miles) SW (234°) from CHARLOTTE AMALIE, US Virgin Islands
72 km (45 miles) ESE (108°) from Bayamon, PR
72 km (45 miles) SE (131°) from Carolina, PR
Location Uncertainty
horizontal +/- 1.3 km (0.8 miles); depth +/- 5.2 km (3.2 miles)
Parameters
NST= 4, Nph= 4, Dmin=44.7 km, Rmss=0.2 sec, Gp=184°,
M-type=duration magnitude (Md), Version=0
Source
Puerto Rico Seismic Network, University of Puerto Rico
Event ID
pr11244001

Be Well.

Magnitude
4.2
Date-Time
Thursday, September 01, 2011 at 20:47:07 UTC
Thursday, September 01, 2011 at 01:47:07 PM at epicenter
Location
34.356°N, 118.455°W
Depth
0.1 km (~0.1 mile) (poorly constrained)
Region
GREATER LOS ANGELES AREA, CALIFORNIA
Distances
7 km (4 miles) ESE (110°) from Newhall, CA
8 km (5 miles) N (349°) from Pacoima, CA
8 km (5 miles) N (349°) from San Fernando, CA
8 km (5 miles) SE (145°) from Santa Clarita, CA
39 km (24 miles) NNW (330°) from Los Angeles Civic Center, CA
Location Uncertainty
horizontal +/- 0.3 km (0.2 miles); depth +/- 0.7 km (0.4 miles)
Parameters
Nph=140, Dmin=6 km, Rmss=0.58 sec, Gp= 22°,
M-type=local magnitude (ML), Version=0
Source
California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR
Event ID
ci11001205

earthquake.usgs.gov...

Yep, felt it, but so minor my dogs didn't even move. Thought I was feeling things.
ETA: Wow, not that far from me, maybe 25 miles. Still not a big shaker.

reply to post by muzzy


Let me gaze into my crystal ball and into the future.

It is now 10 days from today, the 7 days list no longer has 5.9 Santa Cruz. It has moved to the 8 to 30 day list - and I see in the fuzzy glass of my crystal ball it is now a 6.0

1.6 2011/09/01 21:50:12 34.340 -118.448 4.3 6 km ( 4 mi) N of San Fernando, CA
1.6 2011/09/01 21:43:25 34.357 -118.514 5.0 3 km ( 2 mi) SSE of Newhall, CA
2.3 2011/09/01 21:40:48 34.340 -118.460 2.3 6 km ( 4 mi) NNW of San Fernando, CA
3.0 2011/09/01 21:35:34 34.353 -118.452 1.5 7 km ( 5 mi) ESE of Newhall, CA
2.6 2011/09/01 20:53:44 34.341 -118.471 4.9 7 km ( 4 mi) SE of Newhall, CA
1.5 2011/09/01 20:52:38 34.338 -118.480 11.0 6 km ( 4 mi) SE of Newhall, CA
2.0 2011/09/01 20:50:29 34.343 -118.449 6.3 6 km ( 4 mi) N of San Fernando, CA
4.3 2011/09/01 20:47:07 34.343 -118.481 7.4 6 km ( 4 mi) SE of Newhall, CA
1.4 2011/09/01 08:29:32 34.339 -118.491 8.5 5 km ( 3 mi) SE of Newhall, CAA

earthquake.usgs.gov...

gotta little swarm going on

congratulations , always nice to release a bit of stress with a light quake and some dribblers.

Technically I wouldn't call that a swarm, the 1.4 was quite a while before the 4.3 , so really it was a 4.3 main shock and the others since are aftershocks.


7417 responses to the 4.3, that quite a few

reply to post by PuterMan

Probably, should make a note of the post somewhere eh.

I did an update of 16th January NZ quakes the other day and there was one quake

1.831
REF:3448396
LAT/LONG: -38.39383, 177.9301
UTC: 2011/1/16 6:21:10
NZDT: 2011/1/16 19:21:10
DEPTH: 19km
MAG: 1.831ML
LOCATION: 1084 Kanakanaia Rd, Whatatutu 4091
Reported as Felt: No
Revision: revised down from 4.205

I'm going by the ID numbers and the time when comparing the preliminary and the revised, thought it was my mistake at first.
Usually the revisions are 0.001 to 0.5 of a Magnitude
66 Events, 37 additions, 4 deletions, 18 revised down and 11 revised up that day

20th August 2011 Vanuatu. Mag 7.0 Mag 7.1 USGS
Eyewitnesses seem to confirm what the Russians said at the time, the 2nd Mag 7 was bigger than the first.

Australian Colin O’Brien reports;
"The third big one of 7.0 was clearly worse than the first and very severe"

another Australian tourist reports;
"my own personal experience and that of fellow locals and tourists was that the 3rd quake super seeded the previous 2."

earthquake-report.com...

USGS got it wrong

Here's the live seismo for the 4.3 from the LA quake cam

abclocal.go.com...

reply to post by muzzy


First I have not said anything yet as I cannot confirm, but I believe the first quake has been raised to 7.2 and the second 7 to 7.1. This is in the PDE but the web site still reports the original pages @ 7.1 and 7.0

USGS have the first quake at 40Km and EMSC have it at 30km. They are both about 65km form Port Villa and thus have hypocentre distances of 79.3km (USGS) and 71.6km (EMSC).

The second quakes is 25km (USGS) and 10km (EMSC) giving hypocentre distances of 69.6km and 65.7km respectively so the larger of the two quakes was either 6.6km or 5.8km further away depending on which data you use.

Either way I doubt it would make much difference, but I suppose it depends exactly what the shock travelled through on the way and how much the second quake contributed to the rocking of the first quake - note they said it continued for three hours.

The middle 5.9 quake was listed as a 5.9mb by USGS and as a 6.5Mw by EMSC. Looking at the phase data for the two there is little difference, but at no time in the first 7 days was the USGS figure changed from 5.9 in the listings.

Once again as soon as it hits the 8 to 30 day list which not so many look at it changes to 6.5 officially
neic.usgs.gov...

So most out there still think this was a 5.9 and never bother to go back and check. I am noticing more and more that big changes happen AFTER the quakes have left the 7 day list. I don't know if this is just because it takes that time to review them, or because it is intended that way.

You will also see in the 8-30 list the two mag 7s listed as I said above at 7.2 and 7.1 but if you click the links they are 7.1 and 7.2

The Russians also have 7.2 and 7.1 except the order is reversed, i.e. the second is 7.2 and the first 7.1 with the middle one at only 6.0

GFZ Potsdam have 7.0 / 6.4 / 7.0

In my humble opinion the calculations of 4 different agencies seem to be about the same and thus are in all probability correct HOWEVER that does not mean the the perception of the people reporting is wrong or that conditions did not give rise to more apparent shaking for the second big one. Unfortunately peoples perceptions cannot be verified and instrumentation can.

ETA - remember the seismograms I put up at the time? They clearly showed the first quake as much bigger than the second. Additionally USGS forst posted the 7.1 (7.2) as 7.5

earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/at00lqw6d6.php

Magnitude 7.1 - FOX ISLANDS, ALEUTIAN ISLANDS, ALASKA
2011 September 02 10:55:54 UTC

Magnitude 7.1 (Preliminary magnitude — update expected within 15 minutes)
Date-Time

* Friday, September 02, 2011 at 10:55:54 UTC
* Friday, September 02, 2011 at 01:55:54 AM at epicenter

Location 51.758°N, 171.372°W
Depth 39 km (24.2 miles) set by location program
Region FOX ISLANDS, ALEUTIAN ISLANDS, ALASKA
Distances

* 201 km (125 miles) ESE (103°) from Atka, AK
* 215 km (134 miles) SW (233°) from Nikolski, AK
* 363 km (225 miles) E (90°) from Adak, AK
* 1678 km (1043 miles) WSW (241°) from Anchorage, AK

Location Uncertainty Error estimate not available
Parameters NST= 21, Nph= 21, Dmin=200.3 km, Rmss=0.74 sec, Gp=216°,
M-type="moment" magnitude from initial P wave (tsuboi method) (Mi/Mwp), Version=1
Source

* West Coast and Alaska Tsunami Warning Center/NOAA/NWS

Event ID at00lqw6d6

reply to post by jjjtir


Wonder why its a 6.4 here...


Magnitude mb 6.4
Region FOX ISLANDS, ALEUTIAN ISLANDS
Date time 2011-09-02 10:55:55.0 UTC
Location 52.23 N ; 171.55 W
Depth 40 km
Distances 1675 km SW Anchorage (pop 276,263 ; local time 02:55:55.0 2011-09-02)
1526 km SE Anadyr (pop 10,332 ; local time 23:55:55.0 2011-09-02)
381 km SW Unalaska (pop 3,571 ; local time 02:55:55.0 2011-09-02)

Source

They upgraded it to a 6.9

reply to post by jjjtir


3 Tsunami stations active as well.

reply to post by PuterMan


Sorry, you know I've been away...were there 2 or 3 7+ in Vanuatu?

2nd

USGS just deleted a 4.7 Utah from list. posting screenshot for archival.

originally here earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/uu00007930.php

dyfi still available earthquake.usgs.gov/earthquakes/dyfi/events/uu/00007930/us/index.html

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

Magnitude 4.7
Date-Time

* Friday, September 02, 2011 at 11:03:25 UTC
* Friday, September 02, 2011 at 05:03:25 AM at epicenter

Location 38.070°N, 112.055°W
Depth 9.8 km (6.1 miles) (poorly constrained)
Region UTAH
Distances

* 8 km (5 miles) WSW (248°) from Antimony, UT
* 19 km (12 miles) SE (143°) from Kingston, UT
* 22 km (14 miles) ESE (120°) from Circleville, UT
* 222 km (138 miles) ENE (76°) from Caliente, NV
* 299 km (186 miles) S (183°) from Salt Lake City, UT

Location Uncertainty horizontal +/- 3.5 km (2.2 miles); depth +/- 55.3 km (34.4 miles)
Parameters NST= 14, Nph= 14, Dmin=115 km, Rmss=1.04 sec, Gp= 72°,
M-type=duration magnitude (Md), Version=0
Source

* University of Utah Seismograph Stations

Event ID uu00007930

reply to post by zenius


2 x 7+ and 1 x 6.5 and many 5+

That seems to be the final count!!