There are two types of body waves: compressional (P) waves and shear (S) waves. Primary waves (P-waves) travel the fastest, so they arrive at the recording station (seismograph) first. Secondary or shear waves (S-waves) travel slower than P-waves so they arrive second.
Modified frequency modulation (MFM) is an encoding scheme used by PC floppy disk drives and older hard drives.
11 definitions of ACFM. Meaning of ACFM. What does ACFM stand for? ACFM abbreviation. Define ACFM at AcronymFinder.com