## How do you find the distance of the epicenter from the seismic station?

Measure the difference in arrival times between the first shear (s) wave and the first compressional (p) wave, which can be interpreted from the seismogram. Multiply the difference by 8.4 to estimate the distance, in kilometers, from the seismograph station to the epicenter.

## What is the difference between AP and S-wave?

P waves can travel through liquid and solids and gases, while S waves only travel through solids. Scientists use this information to help them determine the structure of Earth. For example, if an earthquake occurs on one side of Earth, seismometers around the globe can measure the resulting S and P waves.

## How is the arrival time of seismic waves used to determine the epicenter?

The difference in arrival time between the two types of seismic wave can be used to calculate the distance of the earthquake’s epicenter from the seismometer, as the further away an earthquake is, the greater the lag time between the detection of the S waves relative to the P waves. Thanks for contributing an answer to Earth Science Stack Exchange!

## How does a seismologist determine the location of an earthquake?

The procedure is simple to state: guess a location, depth and origin time; compare the predicted arrival times of the wave from your guessed location with the observed times at each station; then move the location a little in the direction that reduces the difference between the observed and calculated times.

## How are travel times determined for an earthquake?

IRIS’ travel times graphic for the 1994 Northridge, CA earthquake (described in No.5. Exploring the Earth Using Seismology) is animated to show how travel times are determined. Seismic waves “bounce” the buildings to merely illustrate arrival times and wave behavior, not to depict reality.

## How can you find the epicenter of an earthquake?

Using the arrival times of the P and S waves from 3 different stations distances to epicenter can be determined. The intersection of the 3 cirles gives epicenter location. Each station on the interactive map recorded an earthquake with a characteristic seismogram.