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The Parameters Sn and Stau are calculated as follows:

S_n&=&\:A_n (\Lambda_n)\:\alpha^2\:+\:B_n (\Lambda_n)\:\alpha\:...
 ...pha& = &\: \left[{{2\:S_h\:\phi}\over{3\:(1-\phi)}}\right ]^{0.5};\end{eqnarray}

where G and $\nu$ are the shear modulus and Poisson's ratio, respectively, of the sediment. The hydrate properties are given by its shear moduli Gh and Poisson's ratio $\nu_h$. The parameter $\alpha$ is the ratio of the cemented contact radius to the grain radius in case of hydrate evenly enveloping the sediment grains.


Here we give the calculation parameters for the sediment, hydrate, water, and gas properties used in the forward modeling approach.

Substance Bulk Modulus [GPa] Shear Modulus [GPa] Density [g/cm3]
Calcite 76.8 32 2.71
Clay 20.9 6.85 2.58
Quartz 36 45 2.65
Water 2.5   1.032
Pure Hydrate 5.6 2.4 0.9
Gas 0.1   0.235

Table 1: Properties of sediment mineralogy, water, gas and pure hydrate and


Here we describe the calculation parameters used for the synthetic modeling.

Layer Thickness [km] Saturation (Model 1) (Model 2) (Model 3)
Water 3.315 100% brine    
Brine sediment 0.2 100% brine    
Hydrate sediment 0.3 31% 23% 0.08%
Gas sediment 0.3 2% gas    
Brine sediment 0.5 100% brine    

Table 2: Model used to calculate synthetic seismograms.

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