Earthquakes are measured by magnitude. Magnitude is determined by the distance of the slip, the length of the fault, and the depth the friction is held. “The smallest earthquakes are the most common. Magnitude 2s are so small they are felt only if someone is very nearby their epicenter, a...
The zircons in the database span nearly the entire history of the Earth, and by far the most noticeable wiggle lines up neatly with the Great Unconformity. When they ran the numbers to see how much erosion would be required to explain a wiggle of that size, they found that it...