Comments on: When an earthquake occurs…? http://earthquakequestions.com/when-an-earthquake-occurs-2.htm Everything You Want To Know About Earthquakes Mon, 23 Apr 2012 18:35:24 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: kveryeffective http://earthquakequestions.com/when-an-earthquake-occurs-2.htm/comment-page-1#comment-4017 kveryeffective Sat, 05 Sep 2009 04:29:11 +0000 http://earthquakequestions.com/when-an-earthquake-occurs-2.htm#comment-4017 D= Distance travel S1= Speed of P waves 8.0 Km/s S2= Speed of S waves 4.5 Km/s T1= Time it took travel the distance for the P waves T2= Time it took to travel the distance for the S waves T2= T1 + 78 seconds S1*T1 = S2*T2 S1*T1 = S2*(T1+78 s) S1*T1 = (S2*T1) + (S2*78s) (S1*T1)-(S2*T1)= S2*78s T1*(S1-S2)=S2*78s T1= (S2*78s)/(S1-S2) T1 = (4.5km/s*78s)/ (8.0-4.5km/s) T1 = 351km/75 km/s T1 = 4.68s D = S1T1 D = 8.0 km/s* 4.68 sec D = 37.44 km Hope this helps. D= Distance travel
S1= Speed of P waves 8.0 Km/s
S2= Speed of S waves 4.5 Km/s
T1= Time it took travel the distance for the P waves
T2= Time it took to travel the distance for the S waves
T2= T1 + 78 seconds

S1*T1 = S2*T2
S1*T1 = S2*(T1+78 s)
S1*T1 = (S2*T1) + (S2*78s)
(S1*T1)-(S2*T1)= S2*78s
T1*(S1-S2)=S2*78s
T1= (S2*78s)/(S1-S2)
T1 = (4.5km/s*78s)/ (8.0-4.5km/s)
T1 = 351km/75 km/s
T1 = 4.68s

D = S1T1
D = 8.0 km/s* 4.68 sec
D = 37.44 km
Hope this helps.

]]> By: aaronireland2003 http://earthquakequestions.com/when-an-earthquake-occurs-2.htm/comment-page-1#comment-4018 aaronireland2003 Sat, 05 Sep 2009 04:29:11 +0000 http://earthquakequestions.com/when-an-earthquake-occurs-2.htm#comment-4018 well if it takes 78 secounds to get to the graph then it gotta be slow. just canculate the figer from the number on the radies of the earths diamiter. the s wave will get there sloower than the p wave. if they p wave went for say 2 kilo miles which is 16.0km/s just to say. but the s wave will get 9 kilo miles in the 2 miles. slowly the p wave will leave the s wave behind and that is why it is 78 secounds late. then just canculate how far the p wave got form the s wave and bam you have the answer. plus if you have the answer why canculate? any way good luck. ;) well if it takes 78 secounds to get to the graph then it gotta be slow. just canculate the figer from the number on the radies of the earths diamiter. the s wave will get there sloower than the p wave. if they p wave went for say 2 kilo miles which is 16.0km/s just to say. but the s wave will get 9 kilo miles in the 2 miles. slowly the p wave will leave the s wave behind and that is why it is 78 secounds late. then just canculate how far the p wave got form the s wave and bam you have the answer. plus if you have the answer why canculate? any way good luck. ;)

]]> By: Mark M http://earthquakequestions.com/when-an-earthquake-occurs-2.htm/comment-page-1#comment-4019 Mark M Sat, 05 Sep 2009 04:29:11 +0000 http://earthquakequestions.com/when-an-earthquake-occurs-2.htm#comment-4019 The S waves would travel 351 km during that 78 seconds they were behind. (4.5 * 78 = 351) That means the P waves need enough time to get 351 km ahead of the S waves. Every second the P waves travel 3.5 km further than the S waves. (8 - 4.5 = 3.5) That means it would have taken 100.29 seconds for the P waves to get that far ahead of the S waves (351 / 3.5 = 100.2857 seconds). In that amount of time the P waves would have traveled 802.29 km (100.29 seconds * 8 km/s) or 8.02 x 105 km. The answer given is likely wrong. The S waves would travel 351 km during that 78 seconds they were behind. (4.5 * 78 = 351) That means the P waves need enough time to get 351 km ahead of the S waves. Every second the P waves travel 3.5 km further than the S waves. (8 – 4.5 = 3.5) That means it would have taken 100.29 seconds for the P waves to get that far ahead of the S waves (351 / 3.5 = 100.2857 seconds). In that amount of time the P waves would have traveled 802.29 km (100.29 seconds * 8 km/s) or 8.02 x 105 km. The answer given is likely wrong.

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