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).
In 2014, she guest starred in Agents of Shield as Isabelle Hartley in the season two premiere, and reprised the role later in episode 15 of season two, 'One Door Closes.' In 2015, Lawless landed the recurring guest role of Countess Marburg in WGN America's Salem.