[EAS] WEA used in NYC bombings

[Robertm]

This was discussed a few weeks ago on one of these EAS lists. 

A simple explanation of the earthquake warning system is that there is a supersonic shock wave that precedes the actual shock wave. This means that the earthquake has commenced. The time between these supersonic waves and the Main shock can be seconds. The problem with public warning is the latency in the various warning systems would not always get the warning through in time. 

Interestingly enough our ancestors had an early warning system. Over the time they observed that dogs went crazy just before a quake. Basically they were responding to the same supersonic pre-tremors that EEW is exploiting. So if you want EEW with low latency, stay close to your dog. 


> On Sep 23, 2016, at 07:15, Mike McCarthy <towers at mre.com> wrote:
> 
> A consortium of CA universities and public agencies are installing a
> network of seismometers around the state. I don't fully understand the
> science other than they have defined the hysterisis of major tremor wave
> travel through the crust.