Question

Select all of the answers that apply.

Triangulation is a process to locate an earthquake. Which statements are true regarding this process?

You must know the difference in the times that S waves and P waves arrive at a seismograph station to determine the distance to the epicenter.

Only one seismograph is needed to locate an earthquake.

You should draw a line from the center of the seismograph station to the epicenter to show its location.

Three seismograph distances must be mapped with circles and the point where they intersect is the epicenter.

Answer 1

the first and last one

Answer 2

The statements which are true regarding Triangulation are;

• You must know the difference in the times the S waves and P waves arrive at a seismograph station to determine the distance to the epicenter.

• Three seismograph distances must be mapped with circles and the point where they intersect is the epicenter

Step-by-step explanation

When finding the distance to the Epicenter first we find the distance between the first P wave and the first S wave. Then locate the point on left side of the chart corresponding to the time the P and S waves were apart. This gives you the point for the distance to the epicenter where the amplitude represents the height of the strongest wave.

To find the Epicenter first check map scale and find the distance to the Epicenter on the map. The scale here is vital because it will give the actual distance of the Epicenter of the Earthquake in Kilometers. Use pair of compass with radius as the distance from your circle center to edge of map. The position of the seismograph will be the centre of the circle where as the Epicenter is located on a point on the edge of the circle drawn.