CMT search - Description of results

Depth

The character that may be appended to the earthquake depth conveys its accuracy:

N

Normal depth (10 or 15 km in oceanic regions, 33 km in continental regions). The depth could not be determined, so is assigned a priori.

G

Geophysically assigned depth. The depth could not be determined, so is assigned, but by using another information source than the seismic waveforms themselves. This could be a report of a surface rupture, indicating the earthquake occurred at the surface.

D

Depth constrained by seismic wave reflection from the Earth's surface. For intermediate and deep earthquakes, this gives the best depth constraint.

blank

Best-fit depth from moment tensor solution.

Moment

Energy radiated by earthquake, in units of dyne-cm. This is not a magnitude, but an absolute measure of energy release.

Plane 1

Plane 2

Orientations of the two equivalent fault planes for the event. The three numbers are the strike, dip and slip for the each plane. Recall that although motion takes place on only one of these planes, motion on the other generates an identical energy radiation pattern. Use other information sources to decide which of the two actually is the fault plane.

• The strike and dip describe the orientation of the fault plane.
• The slip gives the motion of the hanging wall relative to the footwall. It is an angle from horizontal (in the given strike direction), increasing in a counter-clockwise sense, in the fault plane.
• Example: For a fault plane with strike 60 degrees and dip 45 degrees
  • a slip direction of zero means the hanging wall moves N60E relative to the footwall;
  • a slip direction of 90 means the hanging wall moves N30W relative to the footwall;
  • a slip direction of 180 means the hanging wall moves S60W relative to the footwall.