Another Slow Tremor Moving Beneath Olympic Peninsula

reply to post by TrueAmerican


Ugh....I'm going to bed.

In looking at some of the other stations, I just don't know what to make of it.

Mt Hoods latest

Station closest to the active spectograph?

reply to post by westcoast


Yeah wow, you can really see them on that last link you posted... Holy crap... This is very interesting.

Here is the latest update from the official blog page for the PNSN:

Aug 12, 2010 - After moving slightly to the northwest over the past few days the tremor seems to have moved back to near where it started or even slightly to the south. Uhmmm. What is going on here? On the slip side Evelyn Roeloffs points out that one strain meter, B018 has a clear change from its background starting on Aug 8.

LINK to that page

Seems as if they are still scratching their heads, and now it sounds like it isn't following the previous pattern of moving up the coast. It has now moved BACK to the south!

Here is another cool LINK to the sensor arrays.

Here is today's update:

Aug 13, 2010 - The tremor is again moving to the northwest. Comparing the northern edge of it now compared to on Aug 8 it has moved about 35km in 6 days even though the center of each day's locations has moved less than that (~15 km to the west). It remains as strong as ever with some strong bursts showing clearly on stations in the Cascades and San Jaun Islands. At the AofA site the first service run for the two most easterly arrays was completed today but there is no report yet on the nature of the recorded data.

LINK

Edit to add: I am still quite confused over what this is, what kind of waves they are and if it is one contuous or a moving epicenter. I also wonder why it isn't in the news more? I mean, this could be a huge indicator to an absolutely catastrophic quake.

[edit on 14-8-2010 by westcoast]

reply to post by westcoast


And that is why it's not in the news more. I normally think it's in my mind but I swear I feel mini earthquakes from time to time that last awhile, i generally only notice when laying down. I live in sw Washington and maybe it's not in my head.

reply to post by whoshotJR


Same here. For the past year or two. I have been a quake watcher for close to 12 years now and so have been aware of and paid attention to such things. Especially for the past 6 months or so, since the quake in Haiti I have noticed even more.

Today, for instance, the 'pressure' in my ears are back, along with the ringing. Last time this happened was right before the Haiti quake and then again the chile quake.

I have to say this deep tremor stuff has me a little anxious. Especially since it is behaving differently this time. Especially since the experts are stumped.

Here is the latest update:

Aug 14, 2010 - Tremor continues as before with a hint it is bifurcating into a cluster southwest of where it started (now its just east of Shelton) and then a more dispersed patch moving into the eastern Olympic Mountains. The northern edge of this patch is very near the location of our BS array

LINK

This LINK to the short-period stations seem to show it the best.

I also notice the same kinds of things here in NW Oregon, I swear that sometimes I feel the ground kind of shimmy? just a little bit, but there are no earthquakes happening at the time.

And this year, my ears have been ringing and I also notice the changes in pressure. Things just seem different lately.

The information about the deep tremors is very interesting and thank you for the links. The fact that this relatively new and unexplained is kind of scary, along with the new underwater volcano off of Washington.

Here is the latest update from the PNSN:

TAug 15, 2010 - The northern edge of the tremor has reached the Array of Arrays, so good data should be being recorded right now. Some of the tremor locations are right under the AofA team's motel in Sequim (but we are feeling nothing). Here is hoping that everything is working well. The Canadians should soon be seeing it coming at them from the south. There is still a pocket of tremor south near Shelton so it is quite spread out now. ext

LINK


Here is the LINK one more time to an interactive map for the tremor array. It seems to be about a day behind, but is very cool. HERE is a real-time seismo that is almost right in the middle of it. Check out the signal at about 1613. What the HECK is that?

I gotta say it again...this is kinda freaking me out. This is going on under my feet RIGHT NOW. And nobody knows why. Maybe this IS connected to the ringing ears and wierd pressure changes? It started about the same time this tremor got whithin 50 miles of me.

Originally posted by westcoast

WOW!! Okay, gotta add this too:

Real-time tremor map

[edit on 12-8-2010 by westcoast]

Wow indeed, that a great page, loooooooooove the interactive map.

I've just saved it to my SpeedDial and will look in each day along with ya (from a safe distance 9000km away )

If its any help have a read of this about our similar slow quakes near Gisborne, 200 2, 2004 and 2010

They mention your Cascadia events in the 2004 article and similar stuff in Japan (no links that I could see).

This fom the 2004 page

The origin of subduction zone tremor is very unclear, but it may be related to the motion of fluids (perhaps water) in association with the slow slip episodes.

Too bad they don't give the magnitudes on the pop up tags on that map.

Holy Cow 445 events on 15th UTC

[edit on 16-8-2010 by muzzy]

reply to post by westcoast


Think of a "wave" or "current" I looked up the speed of deep water currents. I found they can move very slowly because of the pressure. If water slows down, then moving magma would be greatly slowed also.
hypertextbook.com...

reply to post by westcoast


Think of a "wave" or "current" I looked up the speed of deep water currents. I found they can move very slowly because of the pressure. If water slows down, then moving magma would be greatly slowed also.
hypertextbook.com...
Some meadering currents can travel as slowly as 7 km/day.
If there is a circular motion, the speed may be even slower:oceanmotion.org...
I don't know if the info on water can be related to the actions of a magma chamber, but if the loop had a vertical component, then it might cause the noise and slow tremors as it moved.

[edit on 8/16/2010 by zachi]

reply to post by zachi


****Insert lightbulb icon here***

Okay, so apacheman and I had discussed the whole water comparisson before, but we didn't know there was a documented link. Thanks Muzzy

Zachi...what you said just made it come together for me!!

THEORY WARNING!.....

SO, going back to my OP on my what's going on in wasington thread (where I speculate a large magma chamber is feeding both the cascade range AND a recently discovered underwater volcano off the coast), wouldn't the whole magma flowing in a slow water-like current make sense? I mean, try and picture it: The largest magma chamber yet discovered sits under about half of Washington State, extending out under the seafloor to the Juan de Fuca fault. It is SO large, SO massive, that the magma has its own ebb and flow, like the ocean currents. Perhaps the tidal pull of the moon also affects it (like the ocean), explaining the 14-15 month cycle.

It would also explain why when the Explorer plate broke off the Juan de Fuca plate 5-7 million years ago, it could have displaced a large amount of magma,resulting in the increased magmatic activity and rise of the cascades.


So now, if you still think along those lines, the next question for me is what does it all mean? Why did the deep tremor, (possibly the movement of magma) start in 2002? Why is it increasing, or is just that there are better monitors now? How is it affecting the subduction zone? (I mean, come on, it has to be) What is next?

Here is the latest update:

Aug 16, 2010 - The first complete round of servicing of all AofA arrays is now complete and a quick check of a teleseism shows that all data recovered looks good. So far so good.... The tremor is now located directly under the arrays so this should be fun. Also, Tim Melbourne of CWU reports that preliminary analysis of several GPS sites in southern Puget Sound are now seeing the ETS but need to wait on final orbits to nail down the details. And, Kathleen Hodgkinson of UNAVCO confirms that several strain meters are showing well resolved ETS signals and she provides a summary plot of the obvious ones.

LINK


It's a nice warm night, maybe I'll go outside later and see if I can hear any of the wierd noises I experienced last year.

Well, I didn't make it outside, but I definately plan to tonight.

There was a moderate quake today off vancouver island:

Magnitude 4.2
Date-Time Tuesday, August 17, 2010 at 11:37:58 UTC
Tuesday, August 17, 2010 at 04:37:58 AM at epicenter
Time of Earthquake in other Time Zones

Location 50.793°N, 129.909°W
Depth 10 km (6.2 miles) set by location program
Region VANCOUVER ISLAND, CANADA REGION
Distances 175 km (110 miles) W of Port Hardy, British Columbia, Canada
195 km (120 miles) SW of Bella Bella, British Columbia, Canada
345 km (215 miles) WNW of Campbell River, British Columbia, Canada
540 km (335 miles) WNW of VICTORIA, British Columbia, Canada

Location Uncertainty horizontal +/- 9.9 km (6.2 miles); depth fixed by location program
Parameters NST= 69, Nph= 69, Dmin=564.4 km, Rmss=1.14 sec, Gp=169°,
M-type=body wave magnitude (Mb), Version=6
Source USGS NEIC (WDCS-D)


Event ID us2010abbw

LINK to usgs


If you take a look at the map link provided at the site, you will see that the quake sits right on the fault line. That happens to be part of the explorer plate...the same one that caused the recent Cascadia rise which began 5-7 million years ago.

SO...if I try to tie this into my magma chamber theory, it would make sense for that area to become active right now, during this deep tremor period.

My friend AnnMarie brought up a very good point, that perhaps the 7.9 Alaska quake of 2002 might have something to do with triggering the deep tremors?

I any of this holds any water, I would expect to see continued seismic activity along ANY of the faults, but especially the Eplorer. Maybe, as the tremor moves further north, there could be a larger event triggered by it. IF the event were on the Explorer fault/plate and it was big enough, I will be watching the mountains VERY closely. We are soooooooo long overdue for a big release, AND some serious volcanic activity that this build up/slip that's going on right now is just down-right scary.

Edited to reflect the correct EQ mag for 2002

[edit on 17-8-2010 by westcoast]

Here is todays update:

Aug 17, 2010 - There seems to have been a bit of a lull in tremor amplitude over much of the last day compared to the previous several days when it was roaring. There is a summary envelop plot of the first 10 days of this ETS that shows the daily fluctuations and recent lull. The northern edge of the tremor is now north of the Olympics coast and there is a southern bunch of tremor clearly separated from the rest, south of Olympia.

LINK


The other info in the news today was about a couple of very loud booms, covering a large area of NW Washington. It is being attributed to a couple of jets that were scrambled out of Portland, but I'm not buying it. Here is the thread: ATS THREAD: Sonic Booms shake western washington

The original AP article you posted was written on August 11th and mentions that the tremor was moving towards Vancouver Island. There was a 4.2 quake recorded on Vancouver Island on August 17th. So interesting... Thanks for posting this!

The ETS events didn't start in 2002. That is when the scientists first discovered that they were happening. They most likely have been happening all along.

Geologists didn't even realize there was a problem in the Cascadia region until 15 to 20 years ago and are frantically playing catch-up now. Most buildings and infrastructures that were built pre-1995 are not built to code for earthquakes as California's are.

The 14 month Chandlers Wobble cycle (specifically 14.2 months) is thought to influence the ETS events. Scientists believe that the chances of the 9+ eq on that subduction zone is greatly enhanced during ETS events.

I have saved some interesting links on the subject that I will try to post on this thread. I'm not at home at the moment so don't have access to them right now.

Hey - any of you folks still following this still - appears we are not over by any means here's the last two posts

Sep 6, 2010 - This ETS seems to still be going on as strong or stronger than most. Strong and lengthy tremor continues to move slowly north on Vancouver Island almost reaching the Port Alberni area. The southern batch keeps moving south, now concentrated under Longview, WA. A report from Tim Melbourne of Central Washington University confirms this seismologist's suspicion that geodetic motions seem bigger than many ETS in the past. He thinks motions are on average 40% larger than seen in previous ETS including detectable uplift to the west of mapped tremor locations. Also his "Long Baseline Tilt meters show a beautiful recording (praise be summer weather), maybe 350nr of total tilt, and interesting time dependence." In another week or so some calculated slip models should be available.
Sep 4, 2010 - The AofA experiment is over but this ETS continues with lots of very strong tremor on Vancouver Island and a continuing but weaker batch to the south nearing the Washington-Oregon border. While no experts have sent us any specific information even a seismologist can see substatial motions on many of the GPS instruments in and around the Olympics processed at Central Washington University. It seems that even instruments out near the coast are showing significant motion.

Source

reply to post by Anmarie96


Good catch. I was actually just looking at the Cascadia Tremor Map here and it looks creepy. I wish I understood more about the NW.

www.pnsn.org...

So what is it?
Drilling or tunneling maybe?