S-waves are shear waves that move by displacing atoms perpendicular to the wave’s path. This requires “shear strength,” which only solids possess. Since the outer core is a liquid (molten iron and nickel), it has no shear strength, causing S-waves ...
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The Richter scale “saturates” (fails to distinguish) between very large earthquakes (above 7.0) because it only measures peak wave amplitude. The Moment Magnitude Scale (Mw) measures the total energy by considering the fault area and the amount of slip, providing ...
The Moho is the boundary between the Earth’s crust and the mantle. It was discovered because P-waves traveling through the deeper mantle arrive at distant stations faster than those traveling through the shallower crust. This indicates that the mantle is ...
Tsunamis are caused by the sudden vertical displacement of the seafloor. Thrust or reverse faults, common at subduction zones, push one block of crust upward. This vertical “kick” moves the entire water column above it, creating the massive energy pulse ...
The Richter and Moment Magnitude scales are logarithmic. Each increase of one magnitude releases about 32 times more energy. From magnitude 6.0 to 8.0 is a two-step increase, so the energy released is 32 × 32 = 1,024 times more. ...