COMPUTED (IN SITU) ELASTIC PROPERTIES OF SEDIMENTS IN THE 

 SHALLOW BERING SEA AND IN THE MOHOLE SURFACE • 



Location 



P 



Compressibility 



(X 10" 12 cm 2 /dynes) 

 Solids Sediment Water 



K 



Bulk 



Modulus 



(X 10 12 dynes/cm 2 ) 



Poisson's 

 Ratio 



M 

 Shear Modulus 

 (X 10' 2 dynes/cm 2 ) 



Vs 

 (m/sec) 



A-A' 



1.81 23.183 46.1858 



0.0431 



0.5 



- 



- 



B 



1.79 21.645 44.9534 



0.0462 



0.48 



0.0019 



314 



B' 



1.83 24.254 44.9534 



0.0412 



0.5 



- 



- 



C-C 



1.83 21.694 45.0125 



0.0461 



0.48 



0.0020 



320 



Mohole: 

 Surface 



(2.0) 34.086 41.6614 



0.0293 



0.45 



0.0029 



440 



•See text for derivation and discussion; Mohole (Guadalupe Site) gravity core (GGC-3 of tables 7 and 8) 

 included from Model No. 2. 



Table 6 lists some computed elastic properties of 

 sands from the shallow Bering Sea. The elastic properties 

 of soils and sediments is a subject receiving increased 

 attention in recent years because of the dynamic, impact 

 loading of missile launch pads, highways, etc. These 

 properties are, of course, the basic parameters for studies 

 of acoustics in sediments and will be the subject of a future 

 paper. For the present, an approach can be made by using 

 the following assumptions, measurements, estimates, and 

 computations, as derived from the author's studies and 

 from the literature. l9 ~ 23 



1. A sand has grain-to- grain contacts of randomly- 

 oriented mineral particles. These mineral particles (or 

 crystals), while individually anisotropic as far as elastic 

 properties are concerned, form an aggregate which is 

 isotropic. 



2. Sediment structure responds to light pressures 

 (such as a passing sound wave) according to the basic laws 

 and equations of elasticity which adequately describe the 

 elastic properties of rocks, and most solid and liquid sub- 

 stances. 



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