document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1043516>Question 1043516</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The Magnitude, M, of an earthquake is measured using Richter scale: M= log(I/I_0). A \"great\" earthquake measures about 8 on the scale, while a \"light\" earthquake measures about 4. Does this mean that a great earthquake is twice as intense as a light earthquake? If so, explain why, and if not, explain why not, using mathematical reasoning. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #658641 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=658641\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> M=log (I/Io)<BR>\n" );
document.write( "10^M=I/Io<BR>\n" );
document.write( "Let M=4<BR>\n" );
document.write( "10000=I/Io<BR>\n" );
document.write( "I=10000*Io<BR>\n" );
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document.write( "now let M=8<BR>\n" );
document.write( "10^8=I/Io<BR>\n" );
document.write( "100,000,000=I/Io<BR>\n" );
document.write( "I=100,000,000*Io<BR>\n" );
document.write( "The second earthquake is 10^8/10^4 stronger, or 10,000 times stronger.<BR>\n" );
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document.write( "Twice as strong would be<BR>\n" );
document.write( "I=20,000*Io<BR>\n" );
document.write( "I/Io=20,000<BR>\n" );
document.write( "log (I/Io)=log (20,000)=4.30<BR>\n" );
document.write( "an earthquake of magnitude 4.30 would be twice as strong as one that has magnitude 4.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );