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Gas Hydrate: Why do we study it?

Gas hydrate is an important topic for study for three reasons:

1. It contains a great volume of methane, which indicates a potential as a future energy resource.

   When hydrate fills the pore space of sediment, it can reduce permeability and create a gas trap. Such trapping of gas beneath hydrate may cause the formation of the most concentrated hydrate deposits, due to the presence of a reservoir of gas below the hydrate zone. The gas can continually migrate upwards to fill any open pore spaces. This process, in turn, causes the trap to become more effective, producing highly concentrated methane and methane hydrate reservoirs.

   Gas from hydrate might become a major energy resource if economically profitable techniques could be devised to extract its methane.

2. It may function as a source or sink for atmospheric methane, which may influence global climate

   Methane from the hydrate reservoir might significantly modify the global greenhouse, because methane is ~20 times as effective a greenhouse gas as carbon dioxide, and gas hydrate may contain three orders of magnitude more methane than exists in the present-day atmosphere. Because hydrate breakdown, causing release of methane to the atmosphere, can be related to pressure changes caused by glacial sea-level fluctuations, gas hydrate may play a role in controlling long-term global climate change.

3. It can affect sediment strength, which can initiate landslides on the slope and rise.

   Gas hydrate apparently cements sediment, and, therefore, it can have a significant effect on sediment strength; its formation and breakdown may influence the occurrence and location of submarine landslides. Such landslides may release methane into the atmosphere, which may affect global climate.

   Changes in water pressure due to sea level changes may generate landslides by converting the hydrate to gas plus water, causing significant weakening of the sediment, and generating a rise of pore pressure. Conversely, sea-floor landslides can cause breakdown of hydrate by reducing the pressure in sediments. These interacting processes may cause cascading slides, which would result in breakdown of hydrate and release of methane to the atmosphere.

Title Page - What - Where - Why - How - Who - Resources - Bermuda Triangle - Web Sites