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.
The FMM is a document issued by Mexico's INM (Instituto Nacional de MigraciÃ³n) to Americans, Canadians and other nationalities for vacation purposes. Get A Quote