Online help : Location by circles

Determination of the location of an epicenter of the 'circle method'.
>> The time measured on a seismogram between the arrival of P waves (first) and S waves (seconds assesses the epicentral distance between the recording station to the epicenter.

- Click on a station, press and hold while dragging the mouse until a circle whose radius is consistent with the epicentral distance calculated.
- To determine the probable location of the epicenter, many stations are needed.

