Gas hydrate is commonly called flammable ice, methane ice, methane hydrate.

天然气水合物俗称可燃冰，甲烷水合物。

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They estimate that there could be hundreds of billions of tonnes of carbon stored in methane reservoirs under the ice sheet.

BBC: Antarctic may host methane stores

However, the study warned that further research is needed to determine the long-term impacts of the natural gas hydrates -- essentially methane gas trapped in ice.

CNN: Study: Tap natural gas from Alaska's frozen areas

The findings indicate that ancient deposits of organic matter may have been converted to methane by microbes under the ice.

BBC: Antarctic may host methane stores