now we actually do forecasting ourselves on our open hazards.com website. we ve done some calculations that you can go there and see. i ve written a blog about that that says there s a chance, 4 or 5% chance a year of 6-magnitude earthquake within 60 miles of downtown and 30% chance within three years. that is still not certain within the sense we don t know for sure those things are going to happen. all we can do is calculate probabilities. bill: northridge was 20 years ago this year,. i that s correct. bill: 19984. that was a different fault line in southern california, am i right about that. you are but that is buried thrust faults. these thrust faults are underground. they have very little surface expression. when they rupture as the northridge earthquake did, the are up sure didn t actually come to the surface. so it was underground of course. and caused the shaking and the damage that killed roughly 50 people in that event. those things are very dangerous,
person like you to say, that we are on the verge of a much bigger shake? well, of course it could be. you can t discount that but the standard statistic that we quote for an earthquake like that there is 5% chance of something bigger coming within a week or so. now, that earthquake fault, the pent at that hills fault that that fault eventually occurred on has been only known for a few years. we do know it was the source of 1987 whittier narrows earthquake. that runs from brea and la habra, toward downtown l.a. and probably one of the most damaging or dangerous fault west know about in the l.a. area. bill: how come? because it runs right under downtown. there is very little surface expression and we know very little about frequency on of earthquakes on that fault. bill: 5% chance of indicator, five to 10%, that s it? within a week.