Satellite Detection of a Massive Phytoplankton Bloom Following the 2022 Submarine Eruption of the Hunga Tonga-Hunga HaModified Letter Turned Commaapai Volcano

The largest submarine volcanic eruption of this century led to a dramatic phytoplankton bloom north of the island of Tongatapu, in the Kingdom of Tonga. In the absence of shipboard observations, we reconstructed the dynamics of this event by using a suite of satellite observations. Two independent bio-optical approaches confirmed that the phytoplankton bloom was a robust observation and not an optical artifact due to volcanogenic material. Furthermore, the timing, size, and position of the phytoplankton bloom suggest that plankton growth was primarily stimulated by nutrients released from volcanic ash rather than by nutrients upwelled through submarine volcanic activity. The appearance of a large region with high chlorophyll a concentrations <48 hr after the largest eruptive phase indicates a fast ecosystem response to nutrient fertilization. However, net phytoplankton growth probably initiated before the main eruption, when weaker volcanism had already fertilized the ocean.

Automated summary

The largest submarine volcanic eruption of this century caused a significant phytoplankton bloom north of Tongatapu Island in the Kingdom of Tonga. Using satellite observations, it was confirmed that the bloom was a real event and not an optical artifact caused by volcanic material. The timing, size, and location of the bloom suggest that plankton growth was primarily stimulated by nutrients released from volcanic ash.