Volcanic Ash as a Source of Dissolved Phosphorus in the Ocean

The process of phosphorus migration from volcanic ash and obsidian to seawater was experimentally studied. For obsidian and ash of the Ksudach, Karymskiy, and Eyjafjallajökull volcanoes, the specific mobilization of phosphorus ranges from 0.3 to 5.0 µg P/g with an average value of ～1.5 µg P/g. The maximum dissolved mineral phosphorus input into the ocean as a result of the interaction between pyroclastic material from arc volcanism and seawater is 4500–9000 t/yr, which does not exceed 0.3–0.6% of its input from river runoff.