At https://phys.org/news/2025-04-klauea-volcano-ash-prompted-largest.html … The Kilauea volcano on Hawaii that erupted in 2018 created a massive bloom in North Pacific phytoplankton. The mechanism of such blooms are interesting. In this instance the wind was blowing towards the west of Hawaii and that is where most of the ash ended up. However, the volcano also ejected millions of cubic feet of molten lava into the nearby ocean, and at the same time released an estimated 50 kilotons of sulphuric dioxide and 77 kilotons per day of carbon dioxide into the atmosphere. A double whammy if you like – striking upwards with the ash. A climate change nightmare you might say – but have you heard anyone from the blob go on about it.
As the lava flowed into the ocean it warmed nutrient rich bottom waters. These nutrients than rose towards the suface of the ocean, seeking out the sunlit zone. In the process it stimulated phytoplankton growth – by the sheer increase in the amount of nutrients. The result was the bloom. It could be seen from space.
Volcanic ash can be carried long distances by the wind – especially during explosive eruptions. After this particular volcanic eruption the prevailing winds transported ash particles and these movements were recorded by earth orbiting satellites. Eventually, the ash fell into the ocean, contributing to the bloom formation. Chan Hoc Chow of the National Taiwan Ocean University was the lead author. They used satellite data to detect ocean colour, an indirect measure of the presence or absence of phytoplankton. Iron, and phosphates, in the ash, were capable of stimulating growth by themselves – adding to the bloom process.
When the phytoplankton died and sank to the bottom of the ocean, they were actually transporting organic carbon from the surface – much of what was actually released during the eruption. Therefore, the process, in the long term, was not detrimental to the earth’s carbon load. However, one may wonder, as one may, what would have happened in the wake of the asteroid impact at the end of the dinosaur age. If it coincided, and it probably did so, with global volcanic and tectonic upheavals, such as the Deccan Traps, how much bigger than Kilauea would the subsequent phytoplankton bloom have become. Bearing in mind, of course, that chalk laid down around the same time has all the characteristics of a massive bloom. How could it have remained a pristine white colour over thousands or millions of years?