Figure F17. Estimates of gas hydrate amounts based on two interpretations of the chloride (Cl-) concentration profile. A. Interpretation based on extending two linear trends of chloride data seen above (0-20 mbsf) and below (130-330 mbsf) the GHSZ. This interpretation predicts that gas hydrate is present from 20 to 130 mbsf and results in a larger gas hydrate inventory estimate. B. Interpretation based on extending the lower chloride concentration trend into the GHSZ and using a similar baseline chloride concentration observed at ODP Site 888 (see Fig. F18). This interpretation predicts that gas hydrate is present in the region between 40 and 120 mbsf and results in a more conservative estimate of in situ gas hydrate. Based on comparison with sediment resistivity distributions and seismic records and on the data from Site 888, we favor the more conservative approach in estimating the gas hydrate inventory at this site. BSR = bottom-simulating reflector.

Figure F17. Estimates of gas hydrate amounts based on two interpretations of the chloride (Cl^-) concentration profile. A. Interpretation based on extending two linear trends of chloride data seen above (0-20 mbsf) and below (130-330 mbsf) the GHSZ. This interpretation predicts that gas hydrate is present from 20 to 130 mbsf and results in a larger gas hydrate inventory estimate. B. Interpretation based on extending the lower chloride concentration trend into the GHSZ and using a similar baseline chloride concentration observed at ODP Site 888 (see Fig. F18). This interpretation predicts that gas hydrate is present in the region between 40 and 120 mbsf and results in a more conservative estimate of in situ gas hydrate. Based on comparison with sediment resistivity distributions and seismic records and on the data from Site 888, we favor the more conservative approach in estimating the gas hydrate inventory at this site. BSR = bottom-simulating reflector.