Methane clathrates are found beneath deep-sea near 500 meters
(300-500 metres) depth in the sedimentary rocks. Methane
hydrates are also found in polar regions and in the icy mountains
of Alaska, Siberia regions. It can exist only temperature
conditions below 2 degrees Celsius. Methane hydrate found in
seabed is widely available underneath sea. Methane is formed due
to the bio-decomposition of sea plants and creatures. The bio
sediments are deposited in the seabed and are decomposed due to the
bacterial activity resulting in the formation of methane gas. With
the low temperature together with the high pressure of water
column, the water molecules, trapes methane gas in cage and
forms hydrate crystals. Since the density of these crystals are less
than water, it is expected to float in water under normal
circumstances. But since the methane hydrate crystals are formed
as part of the seabed sediments, it remains stable there. The mid-
depth zone of 300-500 meter is known as the gas hydrate stability
zone, or GHSZ. Temperature below 2 degrees Celsius and the high
pressure of the water column is the reason for this stability.
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