In the specific case of a megatsunami hitting the east coast, in my offhand opinion, it should first be determined as best we can what the best/most likely/worst case timelines might be. If the worst case were within a hundred years, that would call for different measures than 1000 years or 10,000 years.
Obviously, nuclear waste should never be permanently stored there, in any case.
If the putative megatsunami were thought possible within 100-200 years, that would call for a plan to relocate the Capitol and other indispensable infrastructure far enough inland to ensure survival of essential government functions and personnel.
At a personal level, I might simply avoid relocating my home and family to the threatened area.
As far as realistic threats that we can do something about, I think the most urgent may be prolonged power outages of the electric grid due to another Carrington Event, such as happened in 1859. In a case like this, we must rebuild our power grid transformer by transformer, the problem being the USA no longer manufactures transformers. So we'd be SOL. Therefore I strongly think the domestic manufacturing of the essential components and equipment of our civilization must be a vital part of our national capacity and policy.
I hope that is a sufficiently elaborated answer to your question, as you clearly have a good grasp of the basic problems.
Respectfully,
Dotini
It really depends on what you mean my possible in the next 200 years, if you mean probable then something would surely have to be done.
That said, I question America's current resources to be able to 're-locate' its largest city. I see it as far more likely that an efficient evacuation system were put in place, although we both know you cannot move 8 million people in 5 hours or so.
That is all aside from the fact that the threat is posed to a much greater area than Just the one city.
In my eyes, it would require a near certainty of imminent destruction before any significant steps are taken protect those on the east coast, simply because of the scale of what would have to be undertaken to achieve such a goal.
It is a case if 'risk x consequence / cost of preventing measures' and while the consequence potentially very high, so is the cost of prevention, so the risk would have to be significant to see action IMO.
As for the Carrington Event (which I recall is attributed to CME's), its a different ball game. Something realistically can be done if the threat is considered sufficient. Looking at the 'risk x consequence / cost of preventing measures', the cost of preventing measures is not completely off the scale like the previous example, so assuming sufficient risk, it seems like a sensible solution to retain transformer production.
I haven't researched the CME threat fully admittedly, so apologies if I am a bit wide of the mark; but I remember reading that the operators of UK National grid do not consider the expected CME's increase to be of particular threat to our grid, and I would be inclined to trust them as a source.
I'm struggling to form a solid opinion on it as I read many conflicting sources, however if it really is such a risk, then measures really should be taken.
