Good on them. But what a sorry state to be in, when global warming and sea level rise related problems already are a reality in Miami or - of all places - Norfolk's naval base.
You might be referring to the aftermath of the Chesapeake Bay Impact Crater, which is one of the largest craters to have struct Earth.
The crater is classified as a complex crater and as a result of the impact, the asteroid left a "W" imprint in the surface. The land on the outskirts of the crater(The "W") is unstable and is most likely what is calling the region around Norfolk to sink.
Someone with more geology knowledge might have more to say about it however :)
one thing that I don't fully understand yet: there were always storm surges above 2m (?) how come that 50cm sea-rise without any storm surges are already causing problems?
An extreme event that happened once every few years (or decades) might be tolerable, and become a vastly larger problem if it starts happening once a month instead.
New York recovered from Sandy, but the city would need massive changes if that water level became routine.
Having a higher base-line sea level is never going to help with flooding. Remember a component of the rise is that the water is warmer, and warmer water takes up slightly more space, but the real problem is that the increased temperature makes storms more aggressive and from there increases storm surge.
Old: ok so 10cm global sea rise + 15cm tide fluctuation, which might well reverse.
I can't believe some cities are built so close to the water when storm surges and natural tide fluctuation over decades is over 50 cm (20'') as seen in Alaska etc.
^^ This statement still holds somewhat.
