Figure 5. Combined ¹³C C₁ and ¹³C CO₂ profiles of gas and gas hydrate from Sites 994, 995, 996, and 997. Gases from sediment gas, gas tubes, and gas from the pressure coring system are in solid shapes, whereas those of gas hydrate are hollow shapes. ¹³C C₁ of gas hydrate gas closely resembles sediment gas. ¹³C CO₂ of gas hydrate is fractionated by about 15 from the corresponding sediment gas ¹³C CO₂. This relationship is best illustrated by gases from Site 996 and the single measurement from Site 997. At Site 994, gas hydrate ¹³C CO₂ is nearly that of the sediment gas and does not appear fractionated.