Methane clathrate

Methane clathrate is an ice-like crystalline solid in which water molecules form cages that trap methane. It occurs mainly in marine sediments and permafrost under high-pressure, low-temperature conditions.

Clathrate hydrate: A crystalline solid in which water molecules form cages around guest molecules. Methane clathrate is the methane-bearing member of this broader family.
Methane hydrate extraction: Methods for releasing and producing methane from hydrate-bearing deposits. Extraction aims to dissociate clathrate underground and bring the gas to the surface.
Submarine landslide: A downslope movement of sediment on the ocean floor. Hydrate dissociation can weaken sediment and may contribute to slope failure.
Blake Ridge: An underwater ridge off the southeastern United States investigated for marine gas hydrates. Drilling there helped characterize hydrate-bearing sediments and their distribution.
Gas hydrate: A clathrate hydrate containing gas molecules, such as methane, within water cages. This name emphasizes the gas-filled form found in sediments.
Depressurization: A process that lowers pressure in a reservoir to induce fluid or gas release. Lowering reservoir pressure can destabilize methane clathrate without heating it.
Methane emissions: The release of methane into the atmosphere or other environments. Methane escaping hydrate deposits can enter seawater and, in some settings, the atmosphere.
Nankai Trough: A submarine trench south of Japan where tectonic plates converge. Research expeditions have documented methane hydrate deposits in its sediments.
Hydrogen bonding: An attraction between a hydrogen atom bonded to an electronegative atom and another electronegative atom. Hydrogen bonds organize water molecules into the clathrate cage framework.
Thermal stimulation: A method that adds heat to a reservoir to alter the behavior of its fluids or solids. Heating can move hydrate-bearing sediment outside clathrate stability conditions.

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