What do moment tensor beach ball diagrams describe?

The construction of a beach ball diagram is very simple. For each point on the surface of a sphere, the moment tensor describes the magnitude and direction of the first motion. If the direction of motion is inwards, towards the source, the surface is coloured white (red arrows).

What is beach ball diagram?

A focal mechanism, or “beachball”, is a graphic symbol that indicates the type of slip that occurs during an earthquake: strike-slip, normal, thrust (reverse), or some combination. It also shows the orientation of the fault that slipped.

What is the moment tensor of an earthquake?

A mathematical representation of the movement on a fault during an earthquake, comprising of nine generalized couples, or nine sets of two vectors. The tensor depends of the source strength and fault orientation.

What is moment tensor inversion?

Moment tensor inversion is a powerful method to investigate the rupture process of earthquakes in mines, providing information on the geometry of the earthquake source and the moment release. Different approaches have been proposed to estimate the source mechanisms, with some advantages and limitations.