I have this earthquake science question that is really annoying me.

The earthquake measured magnitude 7 on the Richter scale and the following data was recorded.

There is this table with three columns: The first one has the "distance from the epicenter" (km):

1. 200km

2. 400km

3. 800km

4. 1600km

Then the second column says "earthquake amplitude" (mm):

1. 1000mm

2. 250mm

3. 62.5mm

4. 15.6mm

Then the third column says "wave height" (mm):

1. 16000mm

2. 4000mm

3. 1000mm

4. 250mm

The question is, explain using the information given above, why the height of water waves cannot be described in a direct mathematical relationship with distance from epicenter.