Quake Watch 2011

reply to post by MoorfNZ

There isn't much distance between the end of the Greendale Fault, which finishes at Weedons Country Club and the start of the Port Hills Fault which starts (by my reckoning W of Kennedys Bush), so I'm picking they will merge at some stage or perhaps overlap each other as some other NZ faults do

Lake Heron series covered here (on ATS first). There have been a couple/ three more aftershocks since then too.

reply to post by kubacs

Interesting that it happened in the same area as the Tohoku Quake last March.

One should not believe everything that one reads in newspapers

[atsimg]http://files.abovetopsecret.com/images/member/cf197eeb17ec.png[/atsimg]

1 response in Tokyo. Mongolian-born grand champion Yokozuna Hakuho (sumo) fell at his Miyagino stable in Tokyo. The janitor said WTF was that and filed a report of an earthquake with USGS.

reply to post by kubacs


Heck no, not feeling anything...nothing ever happens here in berkeley, well they do but I'm not feeling them. Last time I felt a shake was a few months ago. was a 4 something down near San Jose I believe.

Rare quake off the coast of Northland, NZ couple of days ago

REF:3532690
LAT/LONG: -34.76415, 175.24648
UTC: 2011/6/20 18:17:26
NZST: 2011/6/21 6:17:26
DEPTH: 421km
MAG: 4.502ML
LOCATION: o/s, Knights Terrace, NE of Russell, Northland
Reported as Felt: No
magma.geonet.org.nz...

Map

Originally posted by muzzy
Rare quake off the coast of Northland, NZ couple of days ago

REF:3532690
LAT/LONG: -34.76415, 175.24648
UTC: 2011/6/20 18:17:26
NZST: 2011/6/21 6:17:26
DEPTH: 421km
MAG: 4.502ML
LOCATION: o/s, Knights Terrace, NE of Russell, Northland
Reported as Felt: No
magma.geonet.org.nz...

Map

Just how rare is it, Muzzy?

reply to post by backinblack


For this particular area, and of course generally earthquakes occur at this sort of depth. The deeper quakes are associated with the subduction zones or deep lensing zones depending on your view point and these are from 70 km downwards to the very deep ones between 300km and 600km

Where a depth is not well constrained a default depth is sometimes used. These can vary from one provider to another. USGS tends to use 2km, 20km and 33km as default depths.

Some blogs do not understand that in a situation where there are a large number of quakes in rapid succession if may not always be possible to accurately determine the depths. In these cases a default is used and in large swarms you often find a proportion of 'default' depths.

Depth of focus

This USGS graphic



would seem to be suggesting that the bulk of mag 5 quakes happen at 500 to 800 depth unless I am reading that wrong. I shall have to investigate that.

Just quickly this is the raw data from my database for 3000 quakes between Mag 5 and mag 5.9 worldwide

Depth Number
0 - 9.99, 271
10 - 19.99, 1267
20 - 29.99, 639
30-39.99, 1069
40 - 49.99, 362
50 - 59.99, 233
60 - 69.99, 182
70 - 99.99, 311
100 - 199, 465
200 - 299, 95
300 - 399, 22
400 - 499, 21
500 - 599, 82
600+, 30

Summing the first part
Depth Number
0 - 70, 4023
70 - 99.99, 311
100 - 199, 465
200 - 299, 95
300 - 399, 22
400 - 499, 21
500 - 599, 82
600+, 30

Maybe I am misreading their graph?

Mag 6
Depth Total
0 - 9.99 23
10 - 19.99 137
20 - 29.99 82
30 - 39.99 71
40 - 49.99 17
50 - 59.99 12
60 - 69.99 5
70 - 79.99 5
80 - 89.99 5
90 - 99.99 3
100+ 72

Mag 7
0.9700 1
5.0000 1
9.0000 1
10.0000 1
10.0000 1
12.0000 1
12.3000 1
12.3000 1
12.9000 1
13.0000 1
14.0000 1
17.0000 1
18.0000 1
19.7000 1
20.0000 1
20.6000 1
22.0000 1
23.0000 1
25.0000 1
25.1000 1
26.0000 1
30.0000 1
31.0000 1
32.0000 1
33.1000 1
33.3000 1
34.0000 1
35.0000 2
35.0000 1
35.0000 1
36.0000 1
36.1000 1
39.0000 1
44.0000 1
45.0000 1
46.2000 1
49.0000 1
68.0000 1
81.0000 1
85.7000 1
211.0000 1
297.0000 1
576.8000 1
583.8000 1
585.1000 1
612.2000 1
631.2000 1

Mag 8
18.0000 1
35.0000 1
59.3000 1

Mag 9+
30.0000 1
32.0000 1

reply to post by PuterMan


Thanks for the reply and a great, ongoing thread.

M 4.7 and M 5.3 aprox 20 mns apart in Japan: USGS

reply to post by PuterMan


I suspect I hear too many Sumo men falling down sometimes, PuterMan Thanks for the reminder and correcting the AP with the great visual!

reply to post by berkeleygal


Thanks Berkleygal! Well, at least we know the way to San Jose...for now Hope the activity out west remains safe for everyone.

Originally posted by MoorfNZ

Originally posted by muzzy
Rare quake off the coast of Northland, NZ couple of days ago

REF:3532690
LAT/LONG: -34.76415, 175.24648
UTC: 2011/6/20 18:17:26
NZST: 2011/6/21 6:17:26
DEPTH: 421km
MAG: 4.502ML
LOCATION: o/s, Knights Terrace, NE of Russell, Northland
Reported as Felt: No
magma.geonet.org.nz...

Map

Just how rare is it, Muzzy?

Ummmm how about Neverbefore
Well at the Knights Terrace anyway.
And especially at that depth ...................... unprecedented

Within 200km of that epicenter still quite rare, like 1/120 over 70 years.and that includes 2,s and 3's
Records don't start for Northland until 1942.
Heres a List of them
And an Interactive Map
KML file for Google Earth

The Red Star is the 2011/6/20 one


Maybe it was a mistake, I'll check again in 24hrs.

further to post by muzzy

Well thats interesting, I checked on my interactive maps for the last 4 events on that list (in 2010 and ................ not there

Hmmmm perhaps I should be doing updates and revisons after all.
I'll have to rethink the whole layout of presenting the maps, if I do revisions then the timeline and the depth graphs would be saturated, too many quakes to make any sense of whats going on, when I have revisons in the past there were pretty much 100% more events added to the preliminary data on a daily basis

maybe I need to create a mirror blog just with the revised data .......... with a link off the preliminary pages to each new revised map page. I can't link directly to an interactive map without actually putting the map on a web page somewhere

just thinking aloud here

Any IT genuises out there have any ideas how I can show both preliminary and revised

Sitting here in Bodmin, Cornwall, UK at 0300 GMT listening to music before I hit the sack and was interrupted by what felt like a huge lorry passing my house, only thing is - there are no large lorries pass my house - EVER!

Nothing on the USGS or BGS so no proof, records or picture but believe me when I say it happened. Nothing major but got my attention so thought I would share with you guys here

Oooooosssshhhhhhhh

earthquake.usgs.gov...

Magnitude 7.4 ALASKA

Date-Time

* Friday, June 24, 2011 at 03:09:39 UTC

Region FOX ISLANDS, ALEUTIAN ISLANDS, ALASKA

reply to post by MoorfNZ


Holy crap! That's a BIG red square!

I had a feeling Alaska was in for a biggie.

Lucky no tsunami!

-

Keep your peeper open on Yellowstone -

Alaska is one of those trigger/domino effect places.

Stay alert folks!

reply to post by berkeleygal


A tsunami warning is still in effect B'Gal!!

wcatwc.arh.noaa.gov...

Downgraded to a 7.2 and AEIC Alaska has it at 6.78 www.aeic.alaska.edu...

eta
Seismogram Displays
Nikolski, AK (NIKH BHZ AK --): Jun 23, 2011

earthquake.usgs.gov...

Impressive

another eta
look at this

YMR www.seis.utah.edu...

reply to post by berkeleygal


6.65ML on AEIC now

Been a while since we had a 7 , over 2 months
2011 List
2011 Map

Hey cyber junkies,

Is this area of alaska capable of producing a mega thrust event???