Sorry, but this is going to be a long one.
Let me start by saying that there has been quite a bit going on lately with quakes and weather. I have gotten somewhat wrapped up in other things,
but as always, I seem to be drawn back to the West Coast...and not just becuase I live here.
By chance and through discussions regarding other areas I have once again made some more connections and want to sum it all up here. First, I think I
need to re-cap though. The thread has gotten long and I know there is a lot of info.
Before I get into all the technical stuff...I want to say that I feel very strongly right now that anyone living in California, Southern Oregon and
Western Nevada should be on a heightened alert. Just be aware and make sure you are prepared incase of a large event.
I started this thread out by tying together a few different threads and theories. It has grown from there and I keep seeing more connections and
evidence (in my mind
) of such. I am a very visual person, so I've got a bunch of maps and pictures to help with my points.
FIrst, I spoke of the theorized magma chamber under Washington State, the Deep tremor studies and a couple of off-shore volcanos. I then went on to
connect some of the coastal dots and theorize that the Cascadian Subduction zone extends much further South than commonly accepted based on these
things. I want to expand on that and talk about some new things that I believe are evidence of said subduction zone being active right now.
Here is a map of the West Coast Volcanos (per USGS)
Now....looking at that map, the Cascade Mountain Range and included volcanos extend down into Northern Oregon.
Here is a mapf of the accepted location for the Cascadian Subduction Zone:
SO....as the above maps illustrate, the subduction zone starts offshore, extending inland to where the cascade mountain range is...which ends with the
twin sisters in Northern/mid Oregon. the zone continues South, ending pretty much where the San Andreas begins in Northern California.
As I have said before, I believe that the subduction zone does NOT end there, but continues SE in and through California.....and the that San Andreas
Fault is a SYMPTOM of the stress caused by the subduction zone.
I found what I consider further proof of this when I realized the San Andreas was believed to have formed at about the same time we had our last Mega
thrust earthquake here in pacific Northwest, further validating that the San Andreas was caused by the Cascade Subduction Zone.
To better illustrate how I think these all in together and what is happening with some swarms right now I have made a couple of maps.
First, a map of the San Andreas Fault.....I have added where I think the subduction zone continues and the two current swarms in Mammoth Lakes (Long
Valley Caldera) and on the San Andreas...very near the last hisotric quake.
Those arrows I have drawn (sorry for the poor artwork
) are to indicate where the stress would be directed due to the upheaval and subsequent drop.
(hope that makes sense)
So to get this you have to picture the land mass of the states (North American Plate) with the subducting plate off-shore pushing up under it,
essentially causing the Western edge to fracture and threaten to drop. Now imagine the kinds of stress that would cause on the rest of the land
mass......especially if you add in another crack through the middle; the New Madrid.
I made another map to show how I think that plays against each other (again arrows indicating stress)
(to make it more interesting, I am using a current quake map from USGS)
OKAY...(trying to keep this cohesive)....focusing back on the West coast.
NOW...you need to picture what is going on underneath
It is widely accepted that the Cascade Mountains and volcanos were caused by the subduction zone, AND that the volcanos are fed by the magma caused by
the friction of the subduction zone. Lets look south of there.
In Oregon we also have the Newberry Caldera:
Newberry volcano is a broad shield volcano located in central Oregon. It has been built by thousands of eruptions, beginning about 600,000 years ago.
At least 25 vents on the flanks and summit have been active during several eruptive episodes of the past 10,000 years. The most recent eruption 1,300
years ago produced the Big Obsidian Flow. Thus, the volcano's long history and recent activity indicate that Newberry will erupt in the
In Southern Oregon we have Crater Lake:
Crater Lake was formed after the collapse of an ancient volcano, posthumously named Mount Mazama. This volcano violently erupted approximately
7700 years ago. That eruption was 42 times as powerful as the 1980 eruption of Mount St. Helens. The basin or caldera was formed after the top 5000
feet of the volcano collapsed. Subsequent lava flows sealed the bottom, allowing the caldera to fill with approximately 4.6 trillion gallons of water
from rainfall and snow melt, to create the seventh deepest lake in the world at 1,932 feet. -- Excerpt from: U.S. National Park Service Website:
Crater Lake National Park, 1999
Then we get down into California and the one I want to talk about there is the Long Valley Caldera (which includes Mammoth Lake)
Long Vallery Caldera
Long Valley Caldera is located 20 km south of Mono Lake along the east side of the Sierra Nevada in east-central California. This area of eastern
California has produced numerous volcanic eruptions over the last 3 million years including the massive, caldera-forming eruption 760,000 years ago.
The most recent eruptions occurred just 500 to 600 years ago from vents along the Mono Crater-Inyo crater volcanic chain, which extends south from
Mono Lake into the western part of Long Valley caldera
I want to also point out that the last swarm (in Long Valley) that included several 6+mag quakes and upheavel happened in may of 1980....the same
month and year that Mount Saint helens had numerous quakes in the 4-5 range and ofcourse the fatefull eruption on May 18th, 1980. Coincidence???
So you can probably see by now where I am going with this. NO??
It is widely accepted that calderas are formed by either hot spots (plumes...like Yellowstone), or subduction zones. Long Vallery Caldera is a
mystery. Well, not to me. Look again at the map above. Any of them, really. Using my theory that the subduction zone continues down. it very
nicely ties in all those calderas AND the San Andreas (as a symptom).
NOW....lets look at the current swarms. First, the ones I posted about a short time ago at Crater Lake. Here, I'll re-post it. It was earlier this
Recent Earthquakes near Crater Lake
08/04/26 06:01:35 42.90N 122.16W 18.5 2.0 CC
08/07/23 22:51:09 42.61N 122.40W 14.1 1.9 CC
08/07/23 22:54:12 42.61N 122.40W 13.4 1.9 CC
08/07/23 23:19:26 42.59N 122.40W 4.3 1.6 BD
08/07/24 01:36:54 42.61N 122.41W 18.7 1.6 CC
08/09/03 04:32:08 42.55N 122.44W 8.5 1.2 AC
10/09/30 05:05:02 42.63N 122.40W 11.1 1.6 BC
10/09/30 05:11:12 42.61N 122.40W 12.0 1.6 CC
11/08/04 09:15:18 42.64N 122.39W 4.4 1.7 CD
11/08/04 17:22:31 42.62N 122.39W 3.5 2.2 CC
11/08/04 18:38:20 42.62N 122.40W 4.0 2.5 BC
11/08/05 04:35:38 42.61N 122.39W 14.1 1.9 BC
11/08/05 17:34:37 42.62N 122.38W 2.0 2.4 CC
11/08/05 17:59:02 42.61N 122.39W 16.5 2.6 CC
11/08/05 20:04:13 42.62N 122.40W 10.8 2.3 BC
11/08/05 23:39:57 42.62N 122.40W 14.0 2.5 BC
11/08/05 23:41:34 42.60N 122.40W 13.8 2.0 CC
11/08/05 23:59:50 42.59N 122.42W 17.5 1.7 BC
11/08/06 00:05:20 42.61N 122.40W 8.9 2.8 CC
11/08/06 00:44:01 42.62N 122.40W 15.1 2.3 CC
Now we have some very impressive swarms occuring, like I said at Mammoth lakes (Long valley caldera) and on the San Andreas almost directly across
from it, and near the last historical 7+ mag quake. Here are the latest quakes. I won't include more than the last day or two because it would just
be too much:
First, Mammoth Lakes area:
Ugh....wont let me paste it. Here is a LINK
are over twenty there for the last couple of days, but I can tell you there have been a lot more. I have watched several roll across GEE just while I
have been typing this.
Next, the San Andreas:
Here is the LINK
to that current list. There are just
WAY too many...probably close to a hundred for just a couple of days.
So why am I so intrigued by this NOW? Well, there are some other indicators that there is possibly movement.
The Deep tremors. I just started a new thread on a new ETS (Episodic Tremor and Slip). The array team was taken by surprise because the deep tremors
started up about three months earlier than they expected. The tremors are all clustered on the Northern end of the subduction zone. For example,
take a look at todays
. 536 tremors detected. That's quite a bit of a slow rumble on this end, don't you
think? I have noticed some patterns over the past year with yin-yang. It makes me wonder if perhpas this isn't the next ETS......but another symptom
of the stress building up on the opposite end? Thinking about it in that terms....you might then think that the current swarm at the Long Valley
could be the subduction zone showing foreshocks and the San Andreas swarm yet another symptom of said pressure or upheaval.
I guess I am just asking those interested in this theory to take these ideas of the subduction zone and apply it to what we are seeing on the quake
maps right now. I think that if you look at it in that light....you will be concerned. I know I am.
I'll close with another map. One that I have posted here several times, showing where I think the subduction zone is in relation to everything else.
Please...keep an open mind. Look at this map:
and then look at THIS
current quake map...and think about it.
edit on 27-8-2011
by westcoast because: (no reason given)