OBSERVING SEAFLOOR METHANE SEEPS AT THE EDGE OF HYDRATE STABILITY
This expedition will address knowledge gaps related to the flux of methane and other gases from the U.S. Pacific Northwest seafloor seeps, the rate at which methane is consumed by aerobic oxidation, and the nature and distribution of benthic organisms near seep sites. Comparisons of the new data with those collected in other well-studied seep provinces (for example, the U.S. Atlantic margin) will advance understanding of global methane emissions from the seafloor and their consequences.
The study of seafloor methane seeps and the gas hydrate systems to which they are sometimes linked involves physics (for example, specific temperature and pressure conditions, bubble shape and emission rates), chemistry (for example, oxidation of methane in the sediments and water column), biology (for example, microbial processes that produce some of the methane and destroy most of it; benthic organisms that use methane, sulfur, or other species to power their metabolism), and geology (for example, certain sediment types; rocks produced as a result of methane-related processes). Furthermore, methane seep emissions vary in both space and time, both on the scale of a few seconds and over thousands of years. The methane released at seafloor seeps is also a critical component of the global carbon cycle, and global climate both affects these releases and may in turn be affected by methane that is able to reach the atmosphere across the sea-air interface.
To find out about more about this expedition, visit the research cruise’s webpage.