Must see graphical video of the seismic data compiled for the Japan Earthquake

[orogenicman]

This has to be viewed in its entirety to be appreciated. And believe me, as a geologist, I've seen all kinds of seismic data, but the data from the March 11, 2011 Japan great earthquake, as presented graphically here demonstrates with jaw dropping clarity how truly massive this rupture was!

Timeline Vizualization Map of the Japan Earthquakes in 2011:

[KichigaiNeko]

So what this indicates is that the fault line off Hokkaido has increased activity 200 fold?? What is the name of the fault? The activity seems to be between 0-50km deep... that is rather shallow isn't it??

And no I have next to no knowledge of geology or plate tectonics beyond high school.

[orogenicman]

So what this indicates is that the fault line off Hokkaido has increased activity 200 fold?? What is the name of the fault? The activity seems to be between 0-50km deep... that is rather shallow isn't it??

And no I have next to no knowledge of geology or plate tectonics beyond high school.

The fault is the Miyagi megathrust, which is part of a very active subduction zone, one of the most active on the planet. Yes, the activity is between 0-50 km. But more importantly, it indicates that the entire breadth, width, and depth of that fault was involved in the rupture, and is still moving to this day. 0-50 km is shallow.

[KichigaiNeko]

So what this indicates is that the fault line off Hokkaido has increased activity 200 fold?? What is the name of the fault? The activity seems to be between 0-50km deep... that is rather shallow isn't it??

And no I have next to no knowledge of geology or plate tectonics beyond high school.

The fault is the Miyagi megathrust, which is part of a very active subduction zone, one of the most active on the planet. Yes, the activity is between 0-50 km. But more importantly, it indicates that the entire breadth, width, and depth of that fault was involved in the rupture, and is still moving to this day. 0-50 km is shallow.

This is what I understood. Does this Miyagi fault/ subduction zone extend towards and throughout the Philippines? What of the subduction zone off New Zealand... this has been ringing like a bell for the past 5 months that I am aware...nothing major though

[Anomalocaris]

Is it me or did the level of activity on ruyuku trench and Aleutians trench extending to either side of Rupture zone decline quite a bit once the outbreak started?

If it did decline, does that mean much of the background activity level on these trenches immediately prior to the tohuko quake was driven by unrelieved stress in the tohuko area propagating to adjacent segments of the subduction system? So the big release at tohuko also relieved ruyuku and Aleutians trenches?

[orogenicman]

So what this indicates is that the fault line off Hokkaido has increased activity 200 fold?? What is the name of the fault? The activity seems to be between 0-50km deep... that is rather shallow isn't it??

And no I have next to no knowledge of geology or plate tectonics beyond high school.

The fault is the Miyagi megathrust, which is part of a very active subduction zone, one of the most active on the planet. Yes, the activity is between 0-50 km. But more importantly, it indicates that the entire breadth, width, and depth of that fault was involved in the rupture, and is still moving to this day. 0-50 km is shallow.

This is what I understood. Does this Miyagi fault/ subduction zone extend towards and throughout the Philippines?

This particular megathrust doesn't. There is a different one at the Phillipines.

What of the subduction zone off New Zealand... this has been ringing like a bell for the past 5 months that I am aware...nothing major though

The seismic issue at New Zealand is most closely associated with a major strike-slip (transform) fault across the south Island, though there is also volcanic activity. Here is the current seismic activity for the region around New Zealand:



All of the current activity is north of New Zealand, in the Tonga, Samoa, Fiji region.

Here is the historical seismicity for New Zealand:

[KichigaiNeko]

Isn't that the Kermadec Trench?? It is always active as far as I have been observing (which is only a few years)

[orogenicman]

Is it me or did the level of activity on ruyuku trench and Aleutians trench extending to either side of Rupture zone decline quite a bit once the outbreak started?

If it did decline, does that mean much of the background activity level on these trenches immediately prior to the tohuko quake was driven by unrelieved stress in the tohuko area propagating to adjacent segments of the subduction system? So the big release at tohuko also relieved ruyuku and Aleutians trenches?

It's possible, maybe even likely.

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Isn't that the Kermadec Trench?? It is always active as far as I have been observing (which is only a few years)

Yes it is one of the most active subduction zones.

[KichigaiNeko]

Along with the Ruyuku and Aleutians trenches so it would appear. What is fascinating are the very minor quakes after teh major ones on mainland Australia...not that 1.0 quakes can be called as such... but I have observed that after a major quake on the Pacific Rim 6.0 or higher, triggers little fluctuations on the Australian mainland.

Interesting. but nothing to get alarmed about.

Curious... what dB level of sounds do earthquakes make, if any?

[orogenicman]

Along with the Ruyuku and Aleutians trenches so it would appear. What is fascinating are the very minor quakes after teh major ones on mainland Australia...not that 1.0 quakes can be called as such... but I have observed that after a major quake on the Pacific Rim 6.0 or higher, triggers little fluctuations on the Australian mainland.

Interesting. but nothing to get alarmed about.

Curious... what dB level of sounds do earthquakes make, if any?

I live in Louisville, Kentucky. There was a 5.1 magnitude earthquake in Illinois in 2004 that was felt here. The first jolt woke me up, then I heard a roaring sound that I at first thought was the wind and thought a storm was coming. But it was the sound of the ground shaking as the seismic wave travelled through the city. The roof of my house started squeaking and then the whole house shook for about 30 seconds. I don't know what decibal level it reached, but I can imagine a great quake could be very loud.