"1 r 



100 



200 



300 



400 



B. MODES 7-11 



Figure 7 (continued) . 



Phase Velocity (m sec ^) 



'1 = 



= 4.80 



'2 = 



2.44 



3 = 



1.52 



4 = 



1.15 



'5 



= 



0.88 



6 



= 



0.70 



7 



= 



0.60 



a 



= 



0.53 



9 



0.46 



10 = 



0.41 



11 = 



0.37 



33 



