Geostatistical analysis of seafloor depressions on the southeast margin of New Zealand's South Island - Investigating the impact of dynamic near seafloor processes on geomorphology

摘要

Seafloor depressions are widespread on the present-day continental slope along the southeast coast of New Zealand's South Island. The depressions appear to be bathymetrically constrained to depths below 500 m, correlating to the top of the gas hydrate stability zone, and above 1100 m. Similar depressions observed on the Chatham Rise are interpreted to have formed as a result of gas hydrate dissociation, leading to the hypothesis that a similar origin can be applied for the depressions investigated in this study. Our investigation, however, has found limited geophysical or geochemical evidence to support this hypothesis.