Measuring the magnitude and intensity of earthquakes is subject to enormous misunderstanding; there are several basic methods and scales that can lead to confusion. What does it mean if someone says an earthquake had a magnitude of 7? Or a microseismic event generated by a hydraulic fracturing operation has a magnitude of −2? There are two fundamentally different types of scales commonly used by seismologists to describe earthquakes. A magnitude scale measures the force or energy of an earthquake, but an intensity scale measures the level of shaking which occurs at an observation point on the Earth's surface.

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