The January 2022 eruption of the Hunga Tonga-Hunga Ha'apai (HTHH) volcano released a significant amount of ejecta into the South Pacific Ocean. This study investigates the eruption's impact on the South Pacific Gyre (SPG) biogeochemistry using samples from the GEOTRACES cruise GP21. Surface water neodymium isotopes and rare earth element compositions revealed a substantial volcanic impact in the western SPG, potentially extending eastward. Increased trace metal concentrations and chlorophyll-a suggest nutrient supply stimulating biological response. The eruption released substantial neodymium and iron, comparable to annual global dust fluxes. The study highlights the significant and widespread biogeochemical consequences of the HTHH eruption on the SPG.

Zhouling Zhang, Antao Xu, Ed Hathorne, Marcus Gutjahr, Thomas J. Browning, Kathleen J. Gosnell, Te Liu, Zvi Steiner, Rainer Kiko, Zhongwei Yuan, Haoran Liu, Eric P. Achterberg, Martin Frank