Here in the PNW the one(s) we tend to worry about most will be close in but offshore where the sea floor dives under the continental plate. Buoys can be close t

Here in the PNW the one(s) we tend to worry about most will be close in but offshore where the sea floor dives under the continental plate. Buoys can be close to the source and transmit fast enough to give some of us a minute or two warning thanks to the wave propagation speed difference between radio in the air and P & S waves through the earth.