From left to right: Kathryn Schreiner, assistant professor of chemistry and biochemistry (Univ.
of Minnesota Duluth); Ph D candidate Fenix Garcia-Tigreros (UR); Sparrow; and Kessler, associate professor of earth and environmental sciences, aboard the research vessel in Prudhoe Bay, Alaska.
We present a new method developed for measuring radiocarbon of methane (14CH4) in ancient air samples extracted from glacial ice and dating 11,000-15,000 calendar years before present.
The small size (~20 g CH4 carbon), low CH4 concentrations ([CH4], 400-800 parts per billion [ppb]), high carbon monoxide concentrations ([CO]), and low 14C activity of the samples created unusually high risks of contamination by extraneous carbon.
"But, we found that this ancient methane signal largely disappears and is replaced by a different methane source the closer you get to the surface waters." The methane at the surface is instead from recently produced organic matter or from the atmosphere.
Although the researchers did not examine in this study what prevents methane released from the seafloor from reaching the atmosphere, they suspect it is biodegraded by microorganisms in the ocean before it hits the surface waters.
The amount and 14C activity of extraneous carbon added in the new CH4 conversion line were determined to be 0.23-0.16 g and 23.57-16.22 p MC, respectively.
Chemically, methane is a compound made up of one atom of carbon and four atoms of hydrogen (CH Since the industrial revolution (from around 1750), there has been a 250 per cent increase in the amount of methane in the atmosphere.Despite its prevalence in the atmosphere, there are still many unknowns about methane, and scientists don’t always agree on what affects its levels in the atmosphere.