Confounding Sequence of Big Quakes Rattle Santa Cruz Islands

Originally posted by etrex66
reply to post by TrueAmerican

 

Hi TA

I don't think your wrong I think you have not gone far enough. I realise it's a subduction zone but I have this uneasy feeling that with these shallow depths, could we be looking at the formation of a new island in the Pacfic?
Cheers
Ian

Yeah, I could just see it now:

"We interrupt this program to inform you that a previously unknown, extremely rare, and never before witnessed geologic event has taken place in the south pacific. In all of 10 minutes, two plates collided and a 1000 foot high new island was thrust up out of the sea...The bad news is this has created a 1,000 ft wall of water, due to impact your coast in 20 minutes... We have no further advise at this time. You're dead. Bye! And thanks for all that tax money!"

reply to post by TrueAmerican


Your last post, you must be sleep-deprived. Keep up the good work though, even if it's coffee driven.

Hi TA, another excellent thread.
S&F.

I've just started getting interested in Earth Quakes, i find it a fascinating subject.
I always try following these threads, just so i can learn more about what causes them, and the effects it has on the surrounding environment.

Thanks again....

Oh, I've sent you a u2u, hope you don't mind.

.

Originally posted by TrueAmerican

Originally posted by etrex66
reply to post by TrueAmerican

 

Hi TA

I don't think your wrong I think you have not gone far enough. I realise it's a subduction zone but I have this uneasy feeling that with these shallow depths, could we be looking at the formation of a new island in the Pacfic?
Cheers
Ian

Yeah, I could just see it now:

"We interrupt this program to inform you that a previously unknown, extremely rare, and never before witnessed geologic event has taken place in the south pacific. In all of 10 minutes, two plates collided and a 1000 foot high new island was thrust up out of the sea...The bad news is this has created a 1,000 ft wall of water, due to impact your coast in 20 minutes... We have no further advise at this time. You're dead. Bye! And thanks for all that tax money!"

edit on Wed Feb 6th 2013 by TrueAmerican because: (no reason given)

Thanks for that mental image, TA, That'd be MY coastline! That's why I love watching pnw, its far away!! Water that high, I'd just have to shut my eyes and hold on, I definitely wouldn't be one of the brave types from your chronicles! But really, seeing that Vanuatu quake had got me a tad more anxious, not for the 1000ft scenario, but definitely something bigger than the "8.0"

Hmm, that last 5.0 stretched the rupture area further, and now we got another one coming in on my scope...

Estimate: 5.7 to 6.0 I could go as high as 6.3 maybe... I am very curious as to location...

USGS: 6.2
Lol, look it up, tired of providing links

Wow, that's also shallow at 9.8 km depth! And on the inside part of the zone... Hmm...

Also, that is some 120 km from the supposed "main shock". It's just real tough to call that an aftershock for me.


EDIT: Vasa, no I don't think so, that it has anything to do with that quake, and yeah, of course I saw it...

Any of these possibly related to the mag 5+ showing in Indonesia by any stretch of the imagination?

Magnitude 6.2
Thursday, February 07, 2013 at 00:30:11 UTC
Thursday, February 07, 2013 at 11:30:11 AM at epicenter
Location 11.664°S, 164.960°E
Depth 9.8 km (6.1 miles)



Wow! Look how far away this one is on the other side of the subduction zone.

reply to post by Kitora


Then there was another one, 5.2, about 38 minutes ago, same general area as the last 6.2, but much deeper at 34.2 km

EDIT: Interesting, they just put an update in, a 5.1 just four minutes before the 5.2 from the last paragraph, this one in the same area and just a little deeper at 35.1 km

Look at the change in the depth of the last 4-5 aftershocks.

earthquake.usgs.gov...

I wonder if this is anything to worry about.



Never mind......I now see quite a few more at that depth

There was another 5 a few minutes ago, and a 4.9 back in the day (an hour or so ago).The after/before shocks just keep rolling along, mostly in the same large area for now.

Well no question the average depth of these latest aftershocks has increased, and are going deeper, and closer to subduction depth. It also appears that a possible fault extension may have been ruptured, with its own set of aftershocks...We saw that happen in Japan after the big one.

In looking at the historic seismicity, if another big one was to occur, I have marked a couple spots on this map:


The oval in the upper left, to me is the most likely spot, due to there not having been a big one in that area since 1900 that I could see- and thus, accumulation of more stress there. But the oval on the right also could be a trouble spot.

Another thing that's weird is how this seems to be very off again/on again activity, as opposed to a more linear, gradual reduction of repetitive aftershocks. That also leads me to believe this might not be over yet.


EDIT: But also, if we went by just USGS mags, the second largest quake, 7.0, is exactly one full mag down from the 8.0, which would fit the norm...So maybe it IS done...dunno... So if you want to play it safe and conservative, there you go.

reply to post by TrueAmerican


You almost sound like you know what you are talking about. It's feasible, with the information that you gave, to assume those locations should get movement shortly. How big and how long from now is the question.

Originally posted by TrueAmerican
Another thing that's weird is how this seems to be very off again/on again activity, as opposed to a more linear, gradual reduction of repetitive aftershocks. That also leads me to believe this might not be over yet.

I noticed that as well, earlier tonight when they began to slow. It's almost as if it's shaking on a schedule**, I found the start-stop-start-stop-start-stop pattern to be puzzling. If only we could take a peek into the Earth & figure out what sets this pendulum off, and what causes it to cease.

**I'm in no way, shape, or form suggesting human intervention. Yet unknown natural push-and-pull effects are more likely.

I still say that this thread (or one on this topic) should be the top thread for at least another 48 hours.

There were a couple notable ones in the last few hours, a 6.1 and a 5.3, both at 10 km.

The last four have been exactly at 10km (three at 10km, one at 10.2)

Originally posted by Aleister
There were a couple notable ones in the last few hours, a 6.1 and a 5.3, both at 10 km.

The last four have been exactly at 10km (three at 10km, one at 10.2)

Hard to say whether things are just normalizing or if something larger is coming...

If the next 24 hrs are full of more very spread out 6s, and 5s at varying depths then that could be worrisome I imagine. This pattern has been rather erratic since the first 6s emerged a week ago. I would expect the 6s to really start tapering off later on today if the 8 was the peak of things.

Wow, now this latest 4.9- THAT is a strange location, and according to HS chart, not seen any quake near there since 1900:
link

Hmm. Could be mislocated?

Or... A dormant fault just came awake? Or perhaps rupture area expansion? Interesting.

TA, have you seen the Back Projections for the Mag 8.0?
(the play button is hard to find--it's the small triangle just below the box in the middle of the page)

The EU & GSN models look almost like a train of repeating shocks, moving from the SE to the NW.

Waves hello to my friends...

Watching this area closely as well as you guys...

latest:
M6.7 - 27km SSW of Lata, Solomon Islands
2013-02-07 18:59:16 UTC

earthquake.usgs.gov...

Spending all my time looking for work here in Phoenix

keep up the excellent work TA!

reply to post by berkeleygal


The new 6.6 was at 10km depth as well, many of the recent ones have been measured at exactly 10km. Meaning? (I'm ignorant of earthquake analysis, and am learning from TA as I read this thread)