# Surface wave magnitude scale

## Description

The surface wave magnitude (M_s) scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the earth.

Related formulas## Variables

M_{s} | Surface wave magnitude scale (dimensionless) |

A | The maximum particle displacement in surface waves (magnitude) (dimensionless) |

T | The corresponding period (magnitude) (dimensionless) |

Δ | The epicentral distance (magnitude) (dimensionless) |