2023 Articles

Ash Deposition Triggers Phytoplankton Blooms at Nishinoshima Volcano, Japan.

Kelly, Liam J.; Fauria, Kristen E.; Mittal, Tushar; El Kassar, Jan; Bennartz, Ralf; Nicholson, David; Subramaniam, Ajit; Gupta, Ashok Kumar

Volcanic eruptions can cause organisms known as phytoplankton to multiply and form what is known as a phytoplankton bloom in the ocean. Phytoplankton blooms can impact the life cycle of carbon in the earth system, but it is not always obvious why phytoplankton blooms happen. Using different satellite data, we observe phytoplankton blooms by viewing chlorophyll concentration in the ocean. Nishinoshima is a remote volcano in an area of the Pacific that lacks nutrients necessary for phytoplankton blooms. Nishinoshima erupted in 2019–2020 and deposited lava and ash into the ocean at different times. By looking at the chlorophyll concentration during the time periods lava and ash were deposited into the ocean, we found that chlorophyll concentration increased when ash was deposited into the ocean. These increases in chlorophyll concentration were determined to be phytoplankton blooms. These phytoplankton blooms may utilize nutrients from volcanic ash and the atmosphere, leading to a drawdown of atmospheric carbon.