Glacial Crustal Rebound, Sea Levels and Shorelines

Gas hydrates, solid composites of biogenically derived gasses (mainly methane) combined with water ice, may be present in marine sediments, especially at continental margins, under the correct pressure and temperature conditions. Gas hydrates are detected by direct sampling, and inferred from seismic reSection data when a strong bottom-simulating reSector (BSR) is produced by the seismic velocity contrast between the gas hydrate and the sediment below. Given a depth (and thus pressure) of a bottom-simulating reSector, its temperature can be predicted from known relationships and a heat Sow calculated. Alternatively, heat Sow data can be used to estimate the bottom-simulating reSector temperature. The volume of hydrocarbons contained in marine gas hydrates is large. Changes in eustatic sea level (hence pressure) or bottom seawater temperatures could result in their release and thus increase greenhouse gasses and affect global climate. Further Reading