Origin of Life

Theories and evidence for chemical biopoieses

Gas hydrates and bacteria

Scientists Create, Study Methane Hydrates In 'Ocean Floor' Lab: "Methane hydrates -- which are ice-like cages made of water molecules surrounding individual methane molecules -- are only stable at the very low temperatures and high pressures present at the ocean floor. 'If you try to bring it up, these things fizzle and decompose, releasing the trapped methane,' Mahajan says."

'Frozen' Methane Beneath Ocean Floor : "Among the discoveries of Expedition 311 was a thick section of gas hydrate lying near the seafloor surface beneath an active vent site, known as the 'bull's-eye vent,' where methane gas naturally seeps from the seafloor. This vent site is one of many similar sites observed along the Cascadia Margin and scientists are just starting to understand their role in the overall history of the margin. The episodic nature of the venting and the potential link to earthquake activity, as well as the possible impact on gas release into the ocean and atmosphere, will be researched for many years to come, when future drill site observatories will be linked with the NEPTUNE cable observatory system. Scientists first became interested in gas hydrate in 1982, when it was discovered during a research leg of the Deep Sea Drilling Project, one of two U.S.-sponsored scientific drilling programs that predate IODP. The samples were retrieved from the Middle American Trench region, off the Pacific coast of Guatemala. Since then, gas hydrate has been the focus of numerous studies. "

Bacteria in gas hydrate deposits : "Bacteria from deep sediments which despite high pressures (greater than 1,000 atmospheres), gradually increasing temperatures (from an icy 2°C to over 100°C), great depth (several kilometres) and age (many millions of years) may contain most of the bacteria on Earth.

Some of these bacteria produce methane that accumulates in 'gas hydrates' - a super concentrated methane ice that contains more carbon than all conventional fossil fuels and, therefore, a potentially enormous energy source. However, we know little about gas hydrates as they melt during recovery due to the fall in pressure."

Activities Of Subseafloor Life More Diverse Than Expected: "URI geological oceanographer Steven D'Hondt, co-chief scientist of the expedition and lead author on the Science paper, explained the significance of these findings: "We found bacteria to be alive hundreds of meters beneath the seafloor. Their activities are unexpectedly diverse. Some bacterial species recovered and cultured from these sediments were previously unknown. Other species appear to be distributed throughout the entire subsurface world (on land and beneath the sea). Many of their metabolic activities in these sediments ultimately rely for energy on the surface photosynthetic world.""

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