In the early 1950s, Press turned to seismology, co-authoring with Ewing and Jardetzky a seminal monograph on elastic waves in layered media.
Press' accomplishments in this period include the design of a long-period seismograph, and the first detection of the Earth's normal modes of oscillation ("bell ringing"), excited by the Great Chilean earthquake, a pioneering application of digital processing to seismic recordings.