Ocean sediments in the coastal area were
collected at the Arctic Ocean (Chukchi Sea) and Funka Bay, and interstitial water (pore water) on the surface of the sediments (layers in contact with seawater) was
collected. The organic iodine gas species concentrations in the pore water were then measured with GC-MS system. We have firstly known the
concentrations of organic iodine gas components
in the atmosphere, seawater, and sediments. Their averages are
summarized in the table below.
Iodomethane （CH3I） is a major component (component shown on
left in the table below) of the atmosphere. This is because it exists in a
relatively stable state in the atmosphere. It can also be a major component of seawater.
Diiodo-methane (CH2I2) can also become a major component in seawater (the reason remains
a mystery). Iodoethane is always a minor component in both the atmosphere and
seawater (second component on the left in the table below). We discovered that iodoethane was always a predominantly
major component in the sediment. This is a mystery of the iodine
cycle. We are currently trying to determine the underlying reason by conducting
experiments in which organic matter deposited on the sediment layers is cultured.
in order to solve this mystery.