In recent years, the mainstream media has been talking about the upcoming Cascadia Subduction Zone earthquake, as if we only have one major, offshore fault zone to consider in this event. But, there may be something else to consider. Possibly we should wake up to the fact that we could very likely have much more to deal with during and after this upcoming, potentially record-breaking earthquake event. Let us now learn an important lesson from New Zealand and the Kaikoura earthquake of November 14, 2016.
An article, linked here, is titled 'Kaikoura earthquake ruptured 21 faults - that's possibly a world record.' Yes, this was a very complex earthquake which occurred in New Zealand in 2016, with an unusual number of faults rupturing (or being linked) in the same earthquake event. In all of this, there may be a rather large lesson to be found for those of us who reside in the Cascadia region of North America. So, let us now begin to consider a few facts and a potential scenario.
It is known that the Cascadia Subduction Zone is different from all other subduction zones around the world. Why? Because "it does not even produce the small earthquakes so prevalent in other subduction zones."(link) Why is this? Because Cascadia is so strongly locked. Again, why?
It appears that during the westward movement of the North American continent in earlier times, it overrode and bridged over the ancient oceanic rift system. This effectively locked the two sides of the rift together. This bridging and locking impedes the movement in this, now deeply buried, section of the ancient rift system. For this reason, it takes an incredible amount of geologic stress buildup in the region to finally break things loose --- and that potentially means a much larger quake event --- possibly even a new world record.
There is something to now consider. If it is the deeply-buried (buried about 21 miles down) rift system which ultimately breaks loose to initiate the next Cascadia quake, it could produce quite an event. Not only would the rift system be moving, but things along the offshore subduction zone could also break loose. This could mean two very large, parallel earthquakes happening at the same time. But, there is more to this story.
These deep-seated earthquakes could trigger a number of other faults which are much closer to the surface and produce further and more intense seismic activity. A number of these near-surface faults reside directly beneath major population centers. This could all create quite an overall event and have quite an effect on humanity and structures in the region.
So, there are a few questions to be asked. If the New Zealand earthquake of November 2016 completely surprised everyone (including even the geologists) by rupturing at least 21 faults in just that one quake event, what could Cascadia potentially do? Is a new world record for magnitude, duration and number of faults ruptured in one event just waiting to happen? Instead of living in denial, are you considering things which could help you survive in such an event, plus allow you to more readily thrive in the aftermath?
For further reading:
Current Expectations for a Cascadia Mega-Quake
https://cascadian.neocities.org/cascadiaquake.htm
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