we are 140 years since the last haward fault went off. so, i would say, it's pretty likely it won't slip within the next 10 years. that will give you ground shakesing 3 to 4 times as last time. >> we have, pat and i and i couple of other people have run a program how to prepare in your life and home with problems related to an earthquake. that's not what our discussion is today. it's more of a global policy issues. one is proximity to the fault. how certain are geo technical engineering that the actual proximity of the fault is in fact going to affect how strong the ground motion is? does a mile make a difference? >> it came out in kobe earthquake. >> i was actually there. >> the roof came off. it was hard to stand up. i was 6, 7 miles away. in the city, people couldn't stand up. >> they determined using excellerateom ters. you will have near field effect, the easy way to explain it, if you were standing next to a rail road track. the train makes sound and generates and the sound waves tumble. the same thing happens with an earthquake. th