Does volcanic ash re-mobilisation from its deposits on land contribute to ocean fertilisation?

Recent studies on the iron fertilisation of the surface ocean with volcanic ash are all focused on the immediate time after a volcanic eruption. Here we investigate a post-eruptive effect: volcanic ash may be re-mobilised into the atmosphere from ash deposits on land by wind (Langmann, 2013). Therefore it may fertilise the surface ocean during periods of months to years and not only during a volcanic eruption. Observations confirm such re-mobilisation events, e.g. after the volcanic eruptions of Katmai, Alaska (1912), Mt. Hudson, Chile (1991) and Eyjafjallajökull, Iceland (2010). Even though the Katmai eruption is more than 100 years ago, volcanic ash re-mobilisation events occur until today. Here we report first model simulation results after the volcanic eruption of Mt. Hudson, Chile (1991) focusing on the deposition of volcanic ash into the Atlantic sector of the Antarctic Ocean and its potential to iron- fertilise surface ocean waters