Methane is most commonly associated with the heating of homes, and “fueling” controversy across the global economy. The last place the average person would think to find methane: the bottom of the ocean. Large deposits of methane located at great depths freeze into methane hydrate solids and become embedded in the sand and sediment of the ocean floor. At great ocean depths, they form snowball-like crystals due to cold temperatures and high ocean pressure (Hickey). These hydrate deposits have been found all over the world, in different concentrations depending on the area. For example, in the Pacific Northwest, unusually large deposits have been located off the coast of Washington owing to the unique marine life and its sustainability (Hickey). However, the most notable characteristic associated with methane is not its deep-seated deposits in the ocean, but that it is a component of natural gas.
As these deep-water methane hydrates deposits break into smaller pieces, they float upward into warmer waters. Once they hit warmer waters and lower pressures, they break down into methane gas (Whelan). The gas is released into the water and absorbed by surrounding microbes and organisms. However, some will continue to rise eventually making it to the surface and will be released into the atmosphere. This emancipated methane helps to sustain a variety of organisms at various depth levels that use the gas for energy in the absence of sunlight (Whelan).
Methane gas greatly influences climate change, as it is a powerful greenhouse gas that traps heat twenty times more proficiently than carbon dioxide (Whelan). This compounds the already controversial and worrisome warming of our biosphere. The driving force behind the release of methane gas is the warming of oceans worldwide. Even small changes in ocean temperatures can trigger tremendous releases of methane (Whelan). Sonar images (shown below) have revealed large plumes of methane gas being released from the ocean floor (Hickey). It is estimated that from 1970 to 2013 roughly four million tons of methane gas were released from the coastline of Washington State alone! (Hickey)
Research over the past 40 years displayed that deeper waters appear to be more susceptible to warming, compared to naturally warmer more shallow waters that have a better way of regulating temperature (Hickey). Because deeper waters lack the ability to normalize internal temperatures when confronted with the warming of the atmosphere, the threshold for frozen methane hydrate is being pushed farther and farther offshore (Hickey). This poses a challenge for energy companies interested in harnessing frozen methane hydrate as a new source of natural gas. Countries bordered by oceans containing deposits are particularly interested in the idea of independence from the global trade of natural gas. The United States alone would acquire an estimated 300,000 tct. of natural gas reserve (Whelan). However, because the methane hydrate is stored so deep in the ocean, the acquisition of this potential energy is extremely hard to achieve. Additionally, methane hydrates begin to break down at higher temperatures and lower pressures, presenting a challenge in the mining of the methane from the ocean floor (Whelan). Energy companies would have to develop special techniques to keep the hydrates frozen until ready for use.
Although the promise of a new source of natural gas is attractive to many countries and energy companies, the logistics for production are still far from practical. For now, methane remains a major concern as climate change continues to influence the warming of the oceans and subsequently the release of methane gas. Positively, microbes and bacteria throughout the depths of the ocean will continue to use methane, converting it metabolically into energy. As the oceans warm and more methane is released, changes in ocean chemistry and climate change becomes more and more prevalent every year.
Whelan, Jean K. “When Seafloor Meets Ocean, the Chemistry Is Amazing.”Oceanus Magazine. WHOI, 13 Feb. 2004. Web. 20 Oct. 2016.
Hickey, Hannah. “Warmer Pacific Ocean Could Release Millions of Tons of Seafloor Methane.” UW Today. University of Washington and The National Science Foundation, 09 Dec. 2014. Web. 20 Oct. 2016.