The distance from the earthquake to the observation point is estimated using the arrival time difference of the P-wave and S-wave information needed to determine the distance from the focus of an earthquake to the seismic receiving station.
The distance from the epicenter of an earthquake to the seismic station is determined by the time difference between the first arrival of the P and S waves. This is known as the S-P interval.
Requires triangulation to determine the exact location. Three seismometers are required. A circle is drawn from each of the three different seismometer sites, with the radius of each circle equal to the distance from that seismic receiving station to the epicenter.
Canada was under British rule beginning with the 1763 Treaty of Paris, when New France, of which the colony of Canada was a part, formally became a part of the British Empire.