The travel velocity of these two wave types is not the same (P-waves are faster than S-waves). Thus, if there is an earthquake somewhere, the first waves that arrive are P-waves. In essence, the gap in P-wave and S-wave arrival gives a first estimate of the distance to the earthquake.
With the mysterious U.S. Senator Eddie Morra (Bradley Cooper) providing him with a second drug to counteract NZT's deadly side effects, Brian uses his enhanced abilities to help FBI agent Rebecca Harris (Jennifer Carpenter).
That includes the immortal (and brilliant) Vandal Savage as the big bad, versus a team that includes Ray Palmer (Brandon Routh), White Canary (Caity Lotz), and Hawkgirl (Ciara RenÃ©e), among others. Legends of Tomorrow wonât begin to air until 2016, but its preview has fans speculating.