Gas Hydrate, Eastern Pacific Sea Floor

This fizzing chunk of gas hydrate was recovered from 6 meters below the seafloor during Integrated Ocean Drilling Program (IODP) Expedition 311 in 2005, off the coast of western Canada. Gas hydrate swiftly disintegrates at surface conditions, releasing large quantities of natural gas. It forms from the capture of natural methane, either gas generated by microbial action in the seafloor sediment or gas leaking from deeper petroleum-bearing rocks. Chemically, gas hydrate is a clathrate compound, in which water molecules form cages to trap methane molecules in a crystal structure. Methane clathrates occur all over the world's continental shelves in the ocean and in permafrost areas on land.