Evaluation of Acid Volatile Sulfide (AVS) Distribution in Tidal Mud of the Ariake Sea, Japan (Published)
A remarkable decrease of catch of shells was observed during the last three decades in the Ariake Sea. The higher content of acid volatile sulphide (AVS) is responsible for the unfavourable geoenvironmental condition. In this study, the relationship between the thermal properties of the tidal mud and the AVS is evaluated. The tidal mud was collected from Iida and Higashiyoka tidal flat in the Ariake Sea by using a 90 cm length and 7 cm diameter steel tube sampler. Thermal properties were measured by using the digital thermal properties analyser and the AVS was measured by using the GASTEC 201 H/L method at pre-determined depths in the laboratory. It is found that the AVS value shows peak at the same depth where the volumetric heat capacity value shows the peak. A modification is proposed in the classic depth distribution of AVS in the marine sediments by including the thermal properties of the tidal mud.