Quake Watch 2013

reply to post by MamaJ


Sorry for the delay in responding, MamaJ.
I'm an early riser, and on the east coast--I was up, but headed out the door for a busy day.

The Salton Buttes/Niland swarm is interesting. There are swarms in this area every year, it seems.

Here is an image (from the link above) showing the past 6 days of activity. (15 October isn't showing yet):


The CalVO lists this area at a high-very high threat of future eruption, probably explosive at first & then effusive. But my guess is that any future eruption will be small in size; hopefully small enough to not impact nearby communities.

I also found this informative site, talking about the suspected cause of the swarms, as well as potential for a large earthquake in the area:

A 5x8-kilometer magnetic high beneath Salton Buttes appears to represent either a batholith of a large dike swarm at depth. The dome field, the intrusive rocks, and the geothermal system are all manifestations of a spreading center beneath the sediments of the Colorado River delta, as part of the leaky transform fault that is transitional from the Gulf of California to the San Andreas fault system.

And this...

Scientists have discovered that human-created changes effecting the Salton Sea appear to be the reason why California''s massive "Big One" earthquake is more than 100 years overdue and building up for the greatest disaster ever to hit Los Angeles and Southern California.

Researchers found that strands of the San Andreas Fault under the 45-mile long rift lake have have generated at least five 7.0 or larger quakes about every 180 years. This ended in the early 20th century when authorities stopped massive amounts of Colorado River water from periodically flooding the into this sub-sea level desert basin. Such floods used to regularly trigger major quakes and relieve building seismic pressure but the last big earthquake on the southern San Andreas was about 325 years ago.
Dangerous new fault branches that could trigger a 7.8 quake have recently been discovered under the Salton Sea.

The Ca Coast quake a few days ago which i felt in crescent City, i just found that others felt it also here.

I find it interesting that people are still told to drop and cover after the rescue expert that said people who are found alive in rubble are generally in certain areas, like next to a large piece of furniture but NOt under it, to lay down beside a sofa a bed or large table or close to an outer wall but don't get under stuff.

Our local paper today:

‘Shakeout’ provides practice for big quake

Written by Adam Spencer, The Triplicate October 14, 2013 04:00 pm
Scientists predict that Del Norte County is due for a catastrophic earthquake any day.

That makes it all the more important for Del Norters to know how to protect themselves in an earthquake, and the 2013 Great California Shakeout taking place on Thursday is the perfect time to practice.

On Oct. 17, more than 17 million people will participate in the Great Shakeout Earthquake Drills, practicing “drop, cover and hold on.”

“It’s very important for people to participate in Del Norte County, because it really builds brain memory,” said Cindy Henderson, Del Norte County Emergency Services Manager. “Talking about drop, cover, and hold on is one thing, but doesn’t really become instinct or second-nature until you really practice it. When there’s a real event, we need it to be an instinct, so you instantly duck, cover and hold on.”

The official shakeout drill is scheduled for 10:17 a.m. on Oct. 17. Wherever participants are at that moment, they should “drop, cover and hold on” for at least 60 seconds, and act as if a real earthquake was shaking the ground right then.

To register to participate for the event or for more information, visit shakeout.org/california.

There are 6,651 individuals and organizations in Del Norte County that have registered to participate in this year’s Shakeout, a few hundred short of last year’s participants.

Henderson encouraged more Del Norters to register.

reply to post by Char-Lee


Agreed, its not earthquakes that kill people its buildings collapsing or landslides and tsunamis.
Unlike what the movies show, when was the last time anyone got swallowed up by a big crack in the ground during an earthquake?
Every room in our house (except the toilet and bathroom) has a door to the outside, and our reaction when a 6+ happens is always not to drop, cover and hold, but to step outside and away from the house. After all our roof is made of 6tons of concrete tiles.

reply to post by Olivine


From your article

This ended in the early 20th century when authorities stopped massive amounts of Colorado River water from periodically flooding the into this sub-sea level desert basin. Such floods used to regularly trigger major quakes and relieve building seismic pressure but the last big earthquake on the southern San Andreas was about 325 years ago.

The article was written apparently in 2012 as there is a reference to adorelis.com from then (I don't like that site but never mind).

That would place the last big quake about 1687, which means there should have been another around 1867 which is 38 years before the lake was created by accidental flooding - because there was no lake there before that - and the completion of the Hoover dam saw the cessation of the flooding ~1935.

There seems to me to be some discrepancy there on times, and the statement "Scientists have discovered that human-created changes effecting(sic)* the Salton Sea appear to be the reason why California''s massive "Big One" earthquake is more than 100 years overdue and building up for the greatest disaster ever to hit Los Angeles and Southern California" seems to be conjecture on the part of the authors as no evidence of this is offered and it is my belief that the author is a bit muddled.

Wkikpedia states:

Earthquake geology

The Salton Sea and surrounding basin sits over the San Andreas Fault, San Jacinto Fault, Imperial Fault Zone, and a "stepover fault" shear zone system. Geologists have determined that previous flooding episodes from the Colorado River have been linked to earthquakes along the San Andreas Fault. Sonar and other instruments were used to map the Salton Sea's underwater faults during the study. During the period when the basin was filled by Lake Cahuilla, a much larger inland sea, earthquakes higher than magnitude 7 occurred roughly every 180 years, the last one occurring within decades of the year 1700.

Source (Emphasis above by me)

Lake Cahuilla was created and destroyed naturally, not by human intervention.

Lake Cahuilla was created when the lower Colorado River shifted its course within its delta. Instead of flowing directly south to the head of the Gulf of California, the river's waters were diverted northwest into the Salton Basin, the base of which lay about 80-metre (260 ft) below sea level. Under climatic conditions similar to those of the early twentieth century, it would have taken about two decades of uninterrupted river flow to fill the basin to 12-metre (39 ft) above sea level (D. Weide 1976; Wilke 1978; Waters 1983; Laylander 1997). At that point, the lake would have overflowed to the south, feeding half of its waters through the Rio Hardy to the Gulf but losing the other half through evaporation. When the river shifted its course back to the south, the isolated basin would have taken more than five decades to completely dry out again.

I would venture to suggest that the author of the article is jumping to conclusions and putting two and two together to make five.

PS: The pics are good though!

* I note that although this is a Russian site they still incorrectly use the American effecting instead of affecting. I am not sure why the usage has come about but it is bad English. Oh of course it is American

English spoken, American understood.

BO XIAN
reply to post by PuterMan

 

@PuterMan & @muzzy,

I notice from the NZ 3D and several others . . . IIRC, somewhat even Cascadia though I don't recall for certain on that one . . . MOST of the quakes depicted--up to 1500--my setting--all appear to be in more or less one plane--of whatever relatively narrow thickness.

I only recall Japan being starkly different . . . some of the bigger ones were deeper and many quakes were at quite different depths etc. It was a jumble.

THAT HAS to have implications for what's transpiring and likely to transpire.

Do y'all have any insights or observations relative to that?

Anyone else?

Cascadia



I guess possibly because earthquakes tend to occur in this first band 0-33km. I just dragged this out of my ANSS data



Perhaps the question one should be asking is - if Cascadia exhibits very few deep earthquakes is it actually a Wadati-Benioff zone at all?

reply to post by PuterMan


Ahhhhhhhhhhh . . . just the perceptive insights, knowledge and understanding we depend on you so much for.

THX TONS.

I'm still too ignorant about that zone you speak of. Could you please be so gracious as to give YOUR 1-3 paragraph or so summary? Sorry that I haven't been keeping up on wrapping my mind around that concept, theory very well.

It just struck me so vividly that the Japan situation is VERY DIFFERENT. VERY DIFFERENT. That HAS to have implications for degrees of movement, trauma, death, destruction.

I suppose in some senses not . . . Dramatic quakes are evidently possible in EITHER context. And it wouldn't matter if one got squished from a shallower quake or deeper quake. Squished is still squished.

Nevertheless . . . IT APPEARS to this layman . . . that the Japanese situation is involving forces of much MORE EXTENSIVE portent . . . with much GREATER movement and potential devastation on a far "grander" or more "dramatic" nature.

I've long been skeptical of the prophetic claims that major portions of Japan will literally fall into the sea--go under the waves permanently. After looking at the 3D images . . . I'm far LESS skeptical of those predictions.

.

Magnitude 7.1 - Solomon Islands (193) [T]

+-+16+Oct+13++10%3A31%3A01+UTC)&ll=-6.49000,154.92030&spn=2,2&f= d&t=h&hl=e]Location in Google Maps

• Date-Time: Wednesday, October 16, 2013 @ 10:31:01 UTC
  
• Earthquake location: 6.490°S, 154.920°E,
  
• Earthquake depth: 58.3 km
  
• Distances:
  65km (40mi) WSW of Panguna, Papua New Guinea
  74km (45mi) WSW of Arawa, Papua New Guinea
  377km (234mi) SE of Kokopo, Papua New Guinea
  539km (334mi) ESE of Kimbe, Papua New Guinea
  642km (398mi) WNW of Honiara, Solomon Islands
  
• Event ID: usb000kemb
  

Derived from Event Data Source: USGS
Powered by QVSData

And another 7+

7.1 Bougainville region, Papua New Guinea

2013-10-16 10:31:01 UTC

Approx 33km deep

USGS

EDIT

PM and I were obviously posting at same time

Potential for a Tsunami???

reply to post by SpaceJockey1

Potential for a Tsunami???

According to the USGS system, yes.

The [T] in my post above indicates that the tsunami flag was set in the USGS data.

reply to post by BO XIAN

I'm still too ignorant about that zone you speak of.

No you are not actually. It is called a subduction zone, but since I am not convinced about subduction especially in the light of recent suggestions I call it the WBZ or Wadati-Beniaoff Zone [ETA: which is it's proper name by the way].

That way I don't have to call it a 'subduction' zone whilst possibly denying the 'subduction' theory.

reply to post by PuterMan


Ahhhh . . . I recall your earlier mention of those issues now. Thx.

So . . . essentially . . . if I understand your drift . . .

you are asserting that possibly such regions, zones may well have deeper quakes than other types of geological contexts?

reply to post by PuterMan


Looking at the Tonga area in 3D:

www.iris.edu... gion&sz=med

is that a so called "subduction" zone?

The quakes certainly seem to go from deeper to shallower at a decided angle. Not sure what that means or its implications.

I haven't seen other areas quite that "neatly" depicted in such angled terms.

Would be interesting if there were an option to see the SEQUENCES of those quakes . . . maybe depicted by triangles, cubes etc. with the colors and size cues as well.

I don't recall if the Tonga area is one of those predicted for a rise of new land above the waves, or not.

My aunt and uncle were missionaries there and speak of the people as being quite wonderful relationally.

reply to post by BO XIAN


All of the WBZ have that characteristic angle zone of earthquakes which the dogma of the Church of Geology states is because the plate is subducting. This is despite the apparent fact by calculation that the energy required to overcome the friction is many times the amount of energy available - this is the main reason I hold off from embracing subduction along with the missing thousands of kilometres of subduction by comparison to the spreading.

The only WBZ that displays a very skimpy angular descent and nothing as clear as the other zones, is Cascadia.

I am really saying, is there good cause to describe Cascadia as a 'subduction' zone?

UPDATE to post by PuterMan


All three main providers now have thus under Mag 7

USGS 6.9 6.8
EMSC 6.8 6.9
GFZ 6.7

reply to post by PuterMan


Ahhh.

Thx.

Maybe I'll remember now that a big glitch in the theory is the amount of energy required for the theory to be true . . . is simply not remotely available.

So, you're saying that Cascadia is not evidently a WBZ?


So it should be almost exclusively Strike/Slip?

From what you know . . . what would you expect Cascadia to look like 100,000 years from now? No calculations bother, please, just a wild haired guess from all your pouring over such things.

reply to post by BO XIAN

So, you're saying that Cascadia is not evidently a WBZ?

Yes and No. I am simply pointing out that by comparison to other WBZ it has little to indicate it is such.

Even the Aleutian arc which has a much less defined WBZ than some, has a clear angled depth component



If you look again at the Cascadia graphic it is almost impossible to define that zone.



One would be tempted to say that if not a WBZ it would not have Mag 9 earthquakes but historically we know that it does, or at least it has been calculated that it does? Again however this is based on our or my assumption that because Mag 9 earthquakes are associated with WBZ then this is the only place they occur. Maybe that assumption is erroneous.


Here is the Cascadia map again with a line to show where the angle lies



The problem is also that when you zoom into smaller areas that definition just vanishes completely.

PM, you are a great resident of this site.

Keep up the good work, it does not go unnoticed.

PuterMan
reply to post by Olivine

 

The article was written apparently in 2012 as there is a reference to adorelis.com from then (I don't like that site but never mind).

That would place the last big quake about 1687, which means there should have been another around 1867 which is 38 years before the lake was created by accidental flooding - because there was no lake there before that - and the completion of the Hoover dam saw the cessation of the flooding ~1935.

There seems to me to be some discrepancy there on times, and the statement "Scientists have discovered that human-created changes effecting(sic)* the Salton Sea appear to be the reason why California''s massive "Big One" earthquake is more than 100 years overdue and building up for the greatest disaster ever to hit Los Angeles and Southern California" seems to be conjecture on the part of the authors as no evidence of this is offered and it is my belief that the author is a bit muddled.

Agreed, the author of the web page I linked could have been more clear, but I don't see anything factually inaccurate stated.
Earthquakes and floods don't always arrive on convenient, average timetables.
The last sentence you quoted does not appear to be conjecture. See below

Big earthquakes have occurred under the Salton Sea about once every 180 years over the past 1,000 years, the researchers said.

They studied sediments and discovered that earthquakes occurred repeatedly whenever the Colorado River rapidly flooded the lake basin.

The river periodically changed course, either emptying south into the Gulf of Mexico or north into what became an ancient lake, much larger than the Salton Sea, called Lake Cahuilla.

However, there hasn't been a big earthquake under the Salton Sea for 300 years, which is how long it has been since the last big flood, the study said. (The man-caused mistake that created the Salton Sea in 1905-1907 was small by comparison, so it's not likely to trigger a big earthquake.)

(bolding mine, for emphasis)
source of quoted material
abstract of study referenced

PuterMan
reply to post by Olivine

 

Lake Cahuilla was created and destroyed naturally, not by human intervention.

I would venture to suggest that the author of the article is jumping to conclusions and putting two and two together to make five.

PS: The pics are good though!

* I note that although this is a Russian site they still incorrectly use the American effecting instead of affecting. I am not sure why the usage has come about but it is bad English. Oh of course it is American

English spoken, American understood.

edit on 16/10/2013 by PuterMan because: (no reason given)

I understood the article to say that natural flooding of the Lake Cahuilla/Salton Sea area no longer occurs because of the Hoover dam, not that humans destroyed Lake Cahuilla.

Glad you enjoyed the photos!

I chalk up the use of "effect" instead of "affect" to the author, not an Americanism.

PuterMan

 

So, you're saying that Cascadia is not evidently a WBZ?

Yes and No. I am simply pointing out that by comparison to other WBZ it has little to indicate it is such.

What about the line of volcanoes inboard of the "trench", in the Pacific Northwest?

PuterMan
reply to post by BO XIAN

 

So, you're saying that Cascadia is not evidently a WBZ?

Yes and No. I am simply pointing out that by comparison to other WBZ it has little to indicate it is such.

Even the Aleutian arc which has a much less defined WBZ than some, has a clear angled depth component

If you look again at the Cascadia graphic it is almost impossible to define that zone.

 

Here is the Cascadia map again with a line to show where the angle lies

The problem is also that when you zoom into smaller areas that definition just vanishes completely.

I think I see what you mean.

However, in your first 3D graphic it appears that a ?regression? line?

A line averaging the data points?

could be drawn from lower left (North) yellow clusters up to the right (South) purple clusters with a slope of what about 20-30 degrees off vertical?

Therefore what, I don't have a clue but it appears to me that a case could be made for somewhat of a consistently sloped line of quakes there.

It's still not near as defined as in the Tonga area. And I don't know what it would look like if you added 2,000 quakes. Guess I could check.

I do believe that lots of educated assumptions are at best flawed, if not out-right greatly wrong. Now which ones and how is a whole 'nother kettle of fish. LOL.

THX THX BIG.

Blessings,