Which scale is known to be less effective for measuring earthquake magnitude of deeper quakes?

The Richter Scale is known to be less effective for measuring the magnitude of deeper earthquakes primarily because it was originally designed for measuring shallow earthquakes and primarily uses data from local seismic stations. The scale was developed in 1935 and is based on the amplitude of seismic waves recorded by seismographs. However, for deeper earthquakes, the seismic waves can undergo attenuation and scattering as they travel through the Earth’s crust and mantle, leading to less reliable measurements of their true strength when using this scale.

As a result, for deeper seismic events, other scales, such as the Moment Magnitude Scale, provide a more reliable measurement. The Moment Magnitude Scale takes into account the total energy released by the earthquake, which can better reflect the magnitude of deeper events by analyzing the seismic waves generated over a broader area and accounting for the fault area involved in the event. This makes it a more holistic and accurate measure of an earthquake's energy release, especially for deeper quakes that might not be well represented on the Richter Scale.