I'm in Brooklyn and felt it while on a call with an NJ resident who was the first to say "are we having an earthquake??"
Do earthquakes have a propagation speed? Might she have felt it before me?
Do earthquakes have a propagation speed? Might she have felt it before me?
The surface wave displacements also get amplified in wet or loose soil, so the ground shaking and seismic damage is also much greater areas on top of sediment rather than bedrock. Areas on a river, lake or coast where the land has been extended into the water by dumping fill dirt are the worst--ground shaking is really bad and they are very prone to liquefaction.
The difference between the arrival times (at any given point on earth) of the different phases of seismic waves is a function of the distance from the earthquake itself (the hypocenter) and the observation site. It is close to linear in Euclidian distance relatively near the earthquake hypocenter, but becomes more nonlinear farther from the earthquake, because the wave speeds are faster at depth (denser rock) so the travel paths of the wave fronts (the ray paths) are nonlinear. These differences in arrival times are one of the main ways of locating the hypocenter of an earthquake given observations from seismometers at multiple sites. It's essentially triangulation, except with time differences instead of angles--this is done through solving a system of equations.
Additionally, S-waves can't pass through liquids, so there is the 'S-wave shadow zone' that occupies a large fraction of the side of the earth opposite an earthquake where there are no primary S-wave arrivals--S-waves are blocked by the liquid outer core. This is how we found out that the outer core is liquid!
In California, typically usgs has earthquakes posted before I can feel them. They didn't have this one a few minutes after I felt it, so I feel like automatic earthquake detection is off in this area of the US.
Some industrial equipment shuts down to avoid damage.
[0] https://www.google.com/maps/place/40%C2%B040'58.8%22N+74%C2%...
But in summary, the speed is slower than light, so yes you can find out through telecom faster than it getting to you.
Surface waves yes, body waves not necessarily. But surface waves are more destructive.
Frustrated network architects would disagree!