They go very deep underground (rather than lying on the seafloor) quite a distance out from the coastline, and stay deep underground until they get to the "landing manhole" which is nowhere near the beach. The manhole is generally surrounded by a security perimeter. The "landing station" where the NSA's equipment sits is either in the same compound or (less ideally) very nearby. In the latter case the cable run from the manhole to the landing station has to be protected as well.
The digging that they do on the beach is quite disruptive. It often involves blasting. Beachfront landowners fight these things tooth and nail, which is why the landings tend to be in either highly industrialized port locations (Portland, OR) or middle-of-nowhere rugged rocky beaches that nobody visits or lives near.
>"They go very deep underground (rather than lying on the seafloor) quite a distance out from the coastline, and stay deep underground until they get to the "landing manhole" which is nowhere near the beach. The manhole is generally surrounded by a security perimeter. The "landing station" where the NSA's equipment sits is either in the same compound or (less ideally) very nearby. In the latter case the cable run from the manhole to the landing station has to be protected as well."
This is not true. Cable is only buried when the depth is less than a 1,000 meters. At 1,000 meters and above it just sits on the sea floor.[1] There is also no "manhole" where a cable pop's out of the ocean floor. The NSA does not need to be in a cable landing station, there is no benefit. The wavelengths can be peeled off fibre optic cable anywhere along the path. Hence why they were doing this at an AT&T Central Office on Folsom Street in S.F.[2], nowhere near a cable landing station. Cable landing stations are actually pretty uneventful places, generally some nondescript industrial park. The security there is the same as it is at any IX or data center.
Some original telegraph submarine cables were just dragged up the beach, buried a little, then then ends cut and wired up in a tiny concrete hut at the end of the beach. Do an image search for “Porthcurno cable hut” and read about it at https://en.wikipedia.org/wiki/Porthcurno
Probably. Washington State's cable landings are all in Puget Sound, a similar distance up the Strait of Juan de Fuca.
In the Pacific Northwest the weather on along the coast can get pretty fierce in the winter (wind, storms). You don't tend to see a lot of industrial infrastructure built there.
No. Once they reach land they use public right-aways just like normal service providers. There would be no reason to bury a cable in a river to get it from the coast to the city.
Well, technically they're still on the coastline. Just like docks, marinas, and even cities, they tend to get moved inland along harbors and estuaries where available, for protection from ocean weather and waters. Even San Francisco ('s city center) is on the Bay-facing side of the relevant landmass.
The digging that they do on the beach is quite disruptive. It often involves blasting. Beachfront landowners fight these things tooth and nail, which is why the landings tend to be in either highly industrialized port locations (Portland, OR) or middle-of-nowhere rugged rocky beaches that nobody visits or lives near.