Earthquake Prediction Discussions on other forums

[FACT-MAN-2]

I couldn't read through the whole thing, I stopped here:

After the earthquake in Japan, I decided to take a look at the tectonic plate boundaries to see if there was anything that stood out as a common factor with the quake in New Zealand a couple of months earlier. In my amateur review, there is. The Pacific plate boundary with the Australian plate cuts right through New Zealand at Christchurch.

Uh, no it doesn't. The plate cuts through the opposite side of the island. You know, where the massive mountain ranges are, generated by the two plates pushing up against each other.

Plates can subduct under another plate, which is what commonly occurs when two plates come into collision, and subduction can build big mountain ranges, as it has along the Western extremity of South America (Andes)and Nothern regions of North America (the great St. Elias massif) or they can slide past one another as they are along the San Andreas rift in California.

But "pushing up against one another"? I'm not so sure about that.

Does the Austraian plate have Eastward movement in the region of New Zealand? It seems it'd almost have to have if mountains are being pushed up on New Zealand.

I also recall that the Western boundry of the Pacific plate strikes an almost due north/south line from somewhere just South of where the Japanese quake occurred and extends Southward toward and eventually to New Zealand, right along a line that Vanatu would sit astride or very near.

There's also some "plate jumble" going on around the Southern end of the Japanese islands, where three plates, one rather small, are jostling. I've read that this jostling impedes the southerly movement of the Pacific Plate and gives rise to quakes along its boundary, which is where the Japanese quake of 2010 struck.

Fascinating stuff.

[Stagman]

I couldn't read through the whole thing, I stopped here:

After the earthquake in Japan, I decided to take a look at the tectonic plate boundaries to see if there was anything that stood out as a common factor with the quake in New Zealand a couple of months earlier. In my amateur review, there is. The Pacific plate boundary with the Australian plate cuts right through New Zealand at Christchurch.

Uh, no it doesn't. The plate cuts through the opposite side of the island. You know, where the massive mountain ranges are, generated by the two plates pushing up against each other.

Correct, or at least that bit about where the main fault line is. Christchurch is on a minor sub fault where very little activity was expected. However, since that Sept. 2010 shake it has been shaking there pretty much on a weekly basis.

[FACT-MAN-2]

I couldn't read through the whole thing, I stopped here:

After the earthquake in Japan, I decided to take a look at the tectonic plate boundaries to see if there was anything that stood out as a common factor with the quake in New Zealand a couple of months earlier. In my amateur review, there is. The Pacific plate boundary with the Australian plate cuts right through New Zealand at Christchurch.

Uh, no it doesn't. The plate cuts through the opposite side of the island. You know, where the massive mountain ranges are, generated by the two plates pushing up against each other.

Correct, or at least that bit about where the main fault line is. Christchurch is on a minor sub fault where very little activity was expected. However, since that Sept. 2010 shake it has been shaking there pretty much on a weekly basis.

Aftershocks. They can persist for long periods.

[Mr.Samsa]

Plates can subduct under another plate, which is what commonly occurs when two plates come into collision, and subduction can build big mountain ranges, as it has along the Western extremity of South America (Andes)and Nothern regions of North America (the great St. Elias massif) or they can slide past one another as they are along the San Andreas rift in California.

But "pushing up against one another"? I'm not so sure about that.

It's called an "orogenic belt" - it involves subduction processes, but in general terms, the mountains are formed by the two plates colliding and pushing upwards.

Does the Austraian plate have Eastward movement in the region of New Zealand? It seems it'd almost have to have if mountains are being pushed up on New Zealand.

The plates sort of criss-cross in New Zealand. In the North the Pacific plate is subducted beneath the Australian plate, and down South it's the other way around.

Correct, or at least that bit about where the main fault line is. Christchurch is on a minor sub fault where very little activity was expected. However, since that Sept. 2010 shake it has been shaking there pretty much on a weekly basis.

Cheers for the info, I somehow doubt that the guy quoted in the OP was referencing the minor fault line though. Were they aware of the existence of the fault line before the earthquakes down there? I remember hearing on the news that "geologists didn't know it existed", but I never checked out whether that was a case of journalists exaggerating the truth to make it more impressive, or whether it was true.

[Stagman]

Correct, or at least that bit about where the main fault line is. Christchurch is on a minor sub fault where very little activity was expected. However, since that Sept. 2010 shake it has been shaking there pretty much on a weekly basis.

Cheers for the info, I somehow doubt that the guy quoted in the OP was referencing the minor fault line though. Were they aware of the existence of the fault line before the earthquakes down there? I remember hearing on the news that "geologists didn't know it existed", but I never checked out whether that was a case of journalists exaggerating the truth to make it more impressive, or whether it was true.

To be honest I don't know for certain. When I lived in Christchurch I though I was living a relatively safe place compared to Nelson which is located on several faults that veer off from the 'main divide'. Banks Peninsula, the bit of land jutting out from the coastline near Christchurch, is from what I understand the remnants of a long extinct volcano. If so, then my simple, basic geology logic would lead me to believe there is at least some kind of fault system in the area, and that would have been known to the real deal geologists.

[Mr.Samsa]

To be honest I don't know for certain. When I lived in Christchurch I though I was living a relatively safe place compared to Nelson which is located on several faults that veer off from the 'main divide'. Banks Peninsula, the bit of land jutting out from the coastline near Christchurch, is from what I understand the remnants of a long extinct volcano. If so, then my simple, basic geology logic would lead me to believe there is at least some kind of fault system in the area, and that would have been known to the real deal geologists.

Yeah that makes sense. There was a lot of bullshit and pseudoscience on the news around those times, especially when the Moon Man Ken Ring came along to predict more earthquakes (until he was chased out of town), and I accidentally absorbed some info through osmosis I think, so now I'm trying to figure out what was true and what wasn't.

[The_Metatron]

My commiserations Weaver.

We just had a 6.7 off the west coast of my island.

I knew that would happen.

[Weaver]

I knew you'd say that.

[Onyx8]

Well I didn't get the memo at all.