The earthquake consists of main 3 type of waves, they are "P" Waves (Primary waves), "S" Waves (Secondary Waves) and "R" waves (Rayleigh waves). Though "P" and "S" waves originates from the centre of earthquake simultanously, it saperates as it travels because of characteristics of waves.

It has been established that velocity of  "P" waves is 1.68 to 1.75 times than "S" waves, means "P" waves travels about 1.68 to 1.75 times faster than destructive "S" waves, velocity is depending on the particular soil construction.  For the earthquakes deeper and farther than the place where Quake Alarm™ is installed significant warning time is available.

To calculate "P" and "S" wave separation is : Devide straight line distance between epicentre of an earthquake and the place where Quake Alarm™ is installed by 6.44 to obtain tentative time gap between "P" wave and "S" wave reaching to Quake Alarm™.

Calculating using above formula, for earthquake Gujarat received on 26th January, 2001 was situated about 300 Kms. from Ahmedabad, hence 300 / 6.44 = 46.87 seconds. Time may vary depending upon soil construction where earthquake waves travels through and destructive effect of an earthquake largly depend upon magnitude and duration as well as condition of construction, design factors etc.

There are also "R" waves to consider. "R" waves begin on the surface and are different from "P" and "S" waves because  "R" waves travel even slower than "S" waves and they are high energy and low frequency waves and create even more damage and are extremely dangerous.

Hence, a building which despite having been badly damaged but survived fury of "P" waves and "S" waves may not survive knock of "R" waves.

Hence every additional second obtained by warning given by Quake Alarm™ by detecting "P" waves, could be instrumental in saving valuable lives.