# Earthworm Module:
Ewshear Overview

(last revised 31 October, 2011)

The ewshear module takes data from a specified ring from two sensors assumed to be placed on different floors of a building. By computing the relative drop in shear wave velocity between subsequent time windows, an alarm message is posted to a specified ring when that drop is large enough.

The primary options are:

- Identification of the SCNL for each floor's sensor
- The vertical distance between the two sensors
- Optionally, the threshold (as a percentage change) in velocity drop which will trigger an alarm (default is 20%)

Other options include tapering of the original timeseries.

Module Index | Ewintegrate Configuration File