|
|
Trusted Lifetime subscriber
ID Verified Trusted
ID Verified Trusted
I find this quite scary:
At the South, there have been major fault ruptures, perhaps a bit unusual (Chch and particularly the recent M7.8 event - unusual in that both involved multiple fault ruptures) as well as relatively major events to the North and to the West (Wairarapa). But there's nothing moving much at all in the centre of that zone, right under the Wairarapa, and it's a sharp transition between the slow slip quake and the slow movement under the S Wairarapa.
But they haven't been monitoring these "slow quakes" for long, they probably know that what's going on is bringing forward the inevitable, but does "bringing forward" mean that it's likely to happen in the next year or two instead of the next 100 years, or happen in the next 100 or 500 years instead of the next 10,000 years? I think the answer is that they don't know. Even forgetting a megathrust event to the E and the 1855 event, there have been at least 3 >M7 events in that area, 1934, and 1942 (x2). The 1855 event was preceded by a M7.4- M7.7 event of the Awatere fault in 1849. Plot 150 years of quakes, and there was a tendency for major events to happen in the SI, then be followed by major events in the NI. That could also be 100% coincidence.
The arrows in the chart are relative direction of movement of the Aus plate over the subducting Pacific plate. If this is representative of longer term movement (ie - it's been going on a long time), then something just has to give - sometime.
Trusted
Subscriber
Regards,
Old3eyes
Trusted Lifetime subscriber
Fred99:
I find this quite scary:
At the South, there have been major fault ruptures, perhaps a bit unusual (Chch and particularly the recent M7.8 event - unusual in that both involved multiple fault ruptures) as well as relatively major events to the North and to the West (Wairarapa). But there's nothing moving much at all in the centre of that zone, right under the Wairarapa, and it's a sharp transition between the slow slip quake and the slow movement under the S Wairarapa.
But they haven't been monitoring these "slow quakes" for long, they probably know that what's going on is bringing forward the inevitable, but does "bringing forward" mean that it's likely to happen in the next year or two instead of the next 100 years, or happen in the next 100 or 500 years instead of the next 10,000 years? I think the answer is that they don't know. Even forgetting a megathrust event to the E and the 1855 event, there have been at least 3 >M7 events in that area, 1934, and 1942 (x2). The 1855 event was preceded by a M7.4- M7.7 event of the Awatere fault in 1849. Plot 150 years of quakes, and there was a tendency for major events to happen in the SI, then be followed by major events in the NI. That could also be 100% coincidence.
The arrows in the chart are relative direction of movement of the Aus plate over the subducting Pacific plate. If this is representative of longer term movement (ie - it's been going on a long time), then something just has to give - sometime.
The key is they don't know. What NZ has experienced, ChCh and Seddon and now Waiau, is less than a blink of an eye in tectonics and EQ. All this may well be a one in 10,000 year occurrence. Alpine Fault is every 300 years on average, but they just don't know. We have landed on the moon, and Mars, and sent explorers to comets, asteroids, Jupiter, Pluto and beyond, but we know less about EQ and the depths of our oceans
ID Verified
Trusted Lifetime subscriber
|
|
|
