TABLE 2.

Gas concentrations and stable isotope analyses

SampleGas concn (μM)bConcn of isotopeb
H2CH4COaδ34S S2−δ34S SO42−δ2H H2Oδ18O H2Oδ13C DICδ13C CH4δ2H CH4δ2H H2δ13C C2H6δ2H C2H6δ13C C3H8
Outlet-083001NANANA11.8<DL−27.9−5.0−18.3NANANANANANA
Outlet-091501NANANANA<DLNANANANANANANANANA
Outlet-102401NANANA11.8<DLNANANANANANANANANA
125m-1024010.162,11032.112.7<DLNANA−15.8NANANANANANA
125m-102501NANANANA<DLNANANA−41.2−369<DL−43.3−222<DL
250m-102401NANANA12.3<DLNANA−16.3−39.5−323<DL−43.3−261<DL
250m-1025010.814,7408.6NA<DLNANANANANANANANANA
390m-102401NANANA12.3<DLNANA−15.5−42.2−346<DL−43.6−292<DL
550m-102501NANANA12.0<DLNANA−15.6−40.2−370<DL−43.7−297−43.5
648m-102501NANANA12.7<DLNANA−13.7−40.9−371<DL−44.0−234−42.9
Outlet-110701c16517,500NA11.6<DL−26.9−5.6−16.0−40.2−368−685d−43.1−290−42.0
  • a Measured only in the bailer samples.

  • b NA, not analyzed; DL, detection limit.

  • c C2H4, C3H8, C4H10, He, and N2 were detected in the D8A Outlet-110701 sample at 732, 73, 1, 330, and 2,670 μM, respectively. O2 was below the detection limit for all samples.

  • d Compared to standard mean ocean water.