Quake Watch 2015

a reply to: Darkblade71
Is it odd that it started with a 4.0 with no apparent foreshocks: nothing within 20-30 miles along adjacent faults?

Since then, there have been 4 aftershocks from (in order) 2.4, 1.0, 2.2 and 0.8; local time at posting this is ~11:40 AM PDT. All of these have been at the same approximate location, within 1000 or so feet from each other and all within 1KM of each other in depth.

Coincidentally, this is in the general area of the recent fire at Jenks Lake / Big Bear.

a reply to: Eagleyedobserver
I did look it up, using EMSC search
up until the 13:08:59 M5.3 it was just a series, foreshock, mainshock (5.3mb), aftershocks
Date, Time UTC, Mag, Mag Type, Lat, Lon, Depth
10/09/2015 15:23:27, 4.8, mb, 24.22, 121.87, 15
15/09/2015 17:56:22, 4.8, mb, 24.24, 121.87, 20
15/09/2015 19:37:35, 5.3, mb, 24.25, 121.93, 20
15/09/2015 19:40:31, 4.3, ML, 24.26, 121.83, 18
15/09/2015 19:43:32, 4.1, ML, 24.27, 121.82, 20
15/09/2015 20:43:58, 4.4, ML, 24.28, 121.81, 18
16/09/2015 2:07:18, 4.3, ML, 24.26, 121.82, 16
16/09/2015 6:30:44, 4.1, ML, 24.26, 121.8, 18
16/09/2015 13:08:59, 5.2, Mw, 24.29, 121.91, 15
16/09/2015 13:26:45, 4.4, ML, 24.29, 121.82, 19
16/09/2015 13:30:26, 4.3, ML, 24.29, 121.81, 18
16/09/2015 14:29:59, 4.5, ML, 24.28, 121.77, 21
16/09/2015 17:16:48, 4.5, ML, 23, 120.05, 14

because of the 5 day gap between the first one and the second one (4.8), this series started with the second one, when the 3rd one happened (3.162 bigger) the 2nd one became a foreshock (there is no way to know if a quake is a foreshock until a bigger mainshock happens), then the rest are aftershocks
until the 9th one 13:08:59 a 5.2Mw, then it gets complicated
because the 3rd quake on the list was mb and the 9th one Mw we have to convert to the same magnitude type to see which one was the biggest one
for this we have to go to USGS
the 5.3mb is also 5.3Mw earthquake.usgs.gov...
the 5.2Mw is also 5.2mb earthquake.usgs.gov...

so the 3rd quake at 5.3 mb/Mw is still the Mainshock, and the rest are foreshocks or aftershocks.

As far as Alaska goes, you don't say which series, there are two series in Sept
(Andreanof Is.) there were some low magnitude 5's before and after but the Mainshock was
M5.6, 89km S of Atka, Alaska 2015-09-05 07:00:00 UTC 11.9 km
Despite the other 5's seeming close in decimal point number doesn't change the fact the biggest one is still the Mainshock.

(Fox Is) the mainshock was first, then aftershocks
M5.9, 92km SE of Yunaska Island, Alaska 2015-09-10 10:26:47
With this one it depends what timeline you are analyzing, 24hrs, days, weeks, no quakes in the area 2 days prior, so to me that makes the 5.9 a "new" Mainshock.

With active areas like Alaska, Taiwan, Japan, Turkey, Greece you have to be careful to not include background seismology as foreshocks or aftershocks and just concentrate on the immediate fault length/area and short time period. This is where the multi-day location maps come in handy, you can see a bunch of markers/dots/icons grouped together. Lists can show them too, but not so clearly as many networks (USGS) use obscure location names, or (GFZ, EMSC etc) use large area names which can have unrelated events hundreds of km apart

originally posted by: Eagleyedobserver
I think Taiwan, Molucca Sea, New britain Region P.N.G. is all of the same fault line and we see 5 and 6 pointers there.

They are NOT the same fault line, in fact the only common denominator is Taiwan and Molucca Sea are on the edge of the Phillipine Plate, New Britain is not

sorry if it seems I am picking on you personally, you can think whatever you want.

If you want to see a Classic swarm, here is one from Japan E Off Izu Peninsula 26 Jul-2 Aug 1980
check the graph below the map
clearly it was a normal mainshock (4.9) and aftershocks to start with, then on the 28th another 4.9, then two more 4.9's over the next couple of days.
clearly no obvious Mainshock therefore it was a "Swarm"

Hoping some quake experts are on, my phone just came up with an alert .. 7.9 in Illapel, Chile. 2 quakes one at 22km deep and the other at 8km

Mine just went up with the 7.9 in Chile AND 6.5 in Brazil

Again 7.1 in Chile. What is going on?

earthquake.usgs.gov...

WOW!!

Just wanted to post.

Gotta go check this out.

www.ndbc.noaa.gov...

We have 3 buoy's alerting.


And we have a tsumami Watch.
www.tsunami.gov...

Bouys in event mode, 3 stations now.

Hope all are ok!

earthquake.usgs.gov...

Aftershocks.

6.5 aftershock

CNN website has it at 8.3

First reaction from Cali.

earthquake.usgs.gov...

She was starting to make me alittle nervous.

Im more worried about the Big Bear area . We had this earlier today
earthquake.usgs.gov...

M4.0 - 13km SSE of Big Bear Lake, California


Time
2015-09-16 16:10:47 (UTC)
2015-09-16 09:10:47 (UTC-07:00) in your timezone
Times in other timezones
Nearby Cities
13km (8mi) SSE of Big Bear Lake, California
14km (9mi) S of Big Bear City, California
21km (13mi) NE of Yucaipa, California
40km (25mi) E of San Bernardino, California
42km (26mi) NE of Moreno Valley, California
46km (29mi) NW of Palm Springs, California

So far heres the quake count in Chile minus the really small ones which must be in the 100s

4.9
90km W of Illapel, Chile
2015-09-17 01:09:49 UTC35.0 km

5.0
114km WNW of Illapel, Chile
2015-09-17 00:50:07 UTC10.0 km
5.0
54km SW of Ovalle, Chile
2015-09-17 00:42:56 UTC32.9 km
5.2
81km WSW of Illapel, Chile
2015-09-17 00:22:20 UTC10.0 km

5.3
57km SW of Ovalle, Chile
2015-09-17 00:06:16 UTC10.0 km

5.7
76km WSW of Illapel, Chile
2015-09-16 23:38:05 UTC35.0 km

6.4
25km W of Illapel, Chile
2015-09-16 23:18:42 UTC31.1 km

6.2
70km W of Illapel, Chile
2015-09-16 23:16:05 UTC10.0 km

6.1
44km WSW of Illapel, Chile
2015-09-16 23:03:56 UTC10.0 km
6.3
71km W of Illapel, Chile
2015-09-16 22:59:17 UTC47.8 km

8.3
46km W of Illapel, Chile
2015-09-16 22:54:33 UTC25.0 km

Wow!
All within 24 minutes too!

6.4 *********Now upgraded to a 7.0.********************
25km W of Illapel, Chile
2015-09-16 23:18:42 UTC
31.1 km

6.2
70km W of Illapel, Chile
2015-09-16 23:16:05 UTC
10.0 km

6.1
44km WSW of Illapel, Chile
2015-09-16 23:03:56 UTC
10.0 km

6.3 ***********Upped to a 6.4.********************
71km W of Illapel, Chile
2015-09-16 22:59:17 UTC
47.8 km

8.3
54km W of Illapel, Chile
2015-09-16 22:54:32 UTC
25.0 km

They are evacuating people on the coast,
& Hawaii has a tsunami watch.
WOQ

a reply to: dreamfox1

Heck ya, If I was in that area I would be checking my BOB.

I was planning to go to bed early tonight. Not happening.

originally posted by: muzzy
a reply to: lurksoften
.................. 32,105 Kilo Tons for this year, pretty quiet so far, if we don't get a M7+ before the end of the year it will be the quietest for 15 years.

Oops sorry about that, spoke too soon, right out of east field (to me anyway) a 8.4Mw eh
that will change the pie for 2015 dramatically
as always seems the case, it is usually the areas you are NOT looking at that get the big quakes.
I will be following the aftershocks here
www.sismologia.cl...
they feed the same data to EMSC anyway.

Tsunami impact here www.gdacs.org...
should hit Easter Island in about 1hr 10 minutes

a reply to: muzzy

They seem to going up again.

I just wanted to add, (Not related exactly to Chile) that we have data buoy's going off in the pacific and the Atlantic.

www.ndbc.noaa.gov...

Kinda like the bathtub example. Could that set something else off?

a reply to: crappiekat

Yep, round two? We can do better than an 8....come on Earth. Shake it up!

Nevermind, can't get link to work