either backer for their up and down. but here's the point as you go away along the surface
the actual amplitude a shockwave decreases in a regular fashion by that i mean probably in a mathematically calculated
fashion away in all directions so as a result of that out there someplace where you are are the actual movement all the earth is much much
smaller but you can measure it that's what the seismograph does what would majors is that's that surface ways the come through that once with
white and forth across now this is very instrument has it own calculations now this is not you can't please everybody but when you buy in is rent
here's what they tell you take that amplitude on the seismograph or the seismograms and majored probably millimeters and then they will have a
conversion chart was saying once you know what the amplitude is onyour seismograms you can calculate exactly what the actual motion under your feet
was also note if you can measure the actual motion outhere and if itdecreases in regular fashion to that point it would increase inregular fashion back
to the epicenter by regular fashion again i mean mathematically so here is the deal if you wanna know what the amplitude was back there at the epicenter
all you have to do is to take that. that motion here knowing how for was away you can calculate what that actual amplitude was at the epicenter once you know that
then it is simplecalculation from there tocalculate with the richter scale reading is.so here is thedeal those are all relatively simple calculations
and anytime you have simple calculations like that you can make a NoMograph now wanna know McGrath is simply for example here is a plot and on oneside you have
a scale where you take the PS wave arrival okay you plot that.that is the distance yousee onthe other one you major the amplitude love your surface ways on your
seismograms and that of course is theactual mode movement there at your station and you simplydrawaline between one to the other in between thereis a scale this
is Richter Schiele re to use rewrite of and so no two point any station at all can determine what the Richter scale really was any station to determine that but
determine where it was that takes the records for at least three and of course the more you have the better off you are gonna be no record your measurements are
gonna be nowwatch one just last comment because they are always talking about predicting earthquakes whilea tirade here now you can not predict an earthquake
that thay arelike volcanic eruptions we knowthey are gonna happen just like ipredict. that you heard it here first i predict the next major earthquake
all on the san andreas is goingtobe in the southern area around Los Angeleswhy they have not had one down there for over 150 years you see so anything is been
that long it is gonna happen down there we just had one in a Los Angeles-area when i don't know and see there is the problem nobody can come up with an answer
to the when it gonna be and unless you can predict pretty much right on the money nobody is gonna listen to your who is gonna listen to it he said i predict this
willbe somewhere within the next fifty years whacked fiffty years albeit a big size me thinking sky fifty years and now you see. so in answer the question will we ever
be able to predict earthquakes will we ever be able to predict volcanic eruptions my gut feeling now my gut feeling is if we are it is gonna bealong way into the future
but and for the foreseeable future i would say noel okay so much forearthquakes in seismology