# How do we Locate the Epicenter of an Earthquake?

In the last lesson we learned how we can use a seismogram to determine the distance to the epicenter.  Aside from knowing the distance we may want to also know where in the world the earthquake occurred.

# Step 1:  Find Distances to the Epicenter

### The first thing we need to do is figure out the distance from each seismogram to the epicenter, using the same method we learned in the last lesson.

Seismogram 1:

Difference in arrival times = 4 min 0 sec

Distance to epicenter = 2,800 km

Seismogram 2:

Difference in arrival times = 5 min 40 sec

Distance to epicenter  = 4,000 km

Seismogram 3:

Difference in arrival times = 3 min 0 sec

Distance to epicenter = 1,800 km

# Step 2:  Draw Circles

Now that we know the distance from each location to the epicenter, we need to mark those distances on a map.  However, since we don't know the direction to the epicenter, we need to DRAW CIRCLES AROUND EACH STATION WITH A RADIUS EQUAL TO THE DISTANCE WE JUST FOUND.