Seismic hazards

• The probability of a 6.7 magnitude earthquake in the Los Angeles area within the next 30 years is 60%.
• Concentrations of radon gas in the atmosphere may increase before an earthquake.
• S waves are secondary seismic waves that are slower than P waves, only travel through solids, and cause a sideways motion.
• L waves are surface seismic waves that are the slowest, cause a side-to-side motion, and are the most damaging.
• P waves are primary seismic waves that are the fastest, reach the surface first, travel through liquids and solids, and cause backwards and forward shaking.