I experienced a tremendously vivid dream about an earthquake today. Turns out there was a 4.4 near LA today. My dream was about a major one in the Bay Area and it was pretty intense. Thought I’d post about P-waves….
P-waves are type of elastic wave, also called seismic waves, that can travel through gases (such as sounds), elastic solids and liquids, including the Earth. P-waves can be produced by earthquakes and recorded by seismometers. The name P-wave stands for primary wave, as the P-wave is the fastest among the elastic waves, compared to the S-waves.
Earthquake advance warning is possible by detecting the non-destructive primary waves that travel more quickly through the earth’s crust than do the destructive secondary and Rayleigh waves. The amount of advance warning depends on the delay between the arrival of the P-wave and other destructive waves, generally on the order of seconds up to about a minute maximum for deep, distant, large quakes. The effectiveness of advance warning depends on accurate detection of the P-waves and compensation for ground vibrations caused by local activity (such as trucks or construction work).
