Natural iron fertilization by the Eyjafjallajökull volcanic eruption

Abstract

Aerosol deposition from the 2010 eruption of the Icelandic volcano Eyjafjallajökull resulted in significant dissolved iron (DFe) inputs to the Iceland Basin of the North Atlantic. Unique ship‐board measurements indicated strongly enhanced DFe concentrations (up to 10 nM) immediately under the ash plume. Bioassay experiments performed with ash collected at sea under the plume also demonstrated the potential for associated Fe release to stimulate phytoplankton growth and nutrient drawdown. Combining Fe dissolution measurements with modeled ash deposition suggested that the eruption had the potential to increase DFe by >0.2 nM over an area of up to 570,000 km2. Although satellite ocean color data only indicated minor increases in phytoplankton abundance over a relatively constrained area, comparison of in situ nitrate concentrations with historical records suggested that ash deposition may have resulted in enhanced major nutrient drawdown. Our observations thus suggest that the 2010 Eyjafjallajökull eruption resulted in a significant perturbation to the biogeochemistry of the Iceland Basin.

Temporal and spatial variability of Icelandic dust emissions and atmospheric transport

“…Prospero et al, 2012), where it can fertilize the ocean (e.g. Achterberg et al, 2013). It is therefore important to know how much dust is transported to these regions or systems.…”

Ash iron mobilization through physicochemical processing in volcanic eruption plumes: a numerical modeling approach

“…This phytoplankton bloom was indeed the first direct evidence of a fertilization effect of volcanic ash iron on the surface ocean (Langmann et al, 2010;Hamme et al, 2010). While small-scale ash iron fertilization events (e.g., after the Eyjafjallajökull eruption in 2010, Iceland) trigger perturbations in the local marine biogeochemistry (Olgun et al, 2013b;Achterberg et al, 2013), large-scale events (e.g., the 1991 eruption of Mt. Pinatubo, Philippines) may stimulate the MPP and, in turn, the atmospheric CO 2 drawdown globally (Sarmiento, 1993;Watson, 1997) with significant impacts on the climate system (Robock, 2000).…”

“…We note that as volcanic gas composition can vary considerably, the compositions in Table 3 do not fully reflect all these variations but they satisfactorily represent the geochemical differences between tectonic settings (e.g., water, sulfur, carbon and halogen contents) (Gerlach, 2004). Ash composition in this study refers to the composition of the ash surface rim with a thickness of < 100 nm (Achterberg et al, 2013;Gislason et al, 2011;Hoshyaripour et al, 2014). Table 3.…”

“…Species Cl-rich C-rich S-rich This rim undergoes substantial physicochemical interactions with gases and aerosols within the plume and cloud that can eventually lead to generation of a salt layer on the ash surface (Achterberg et al, 2013;Gislason et al, 2011). This salt layer is suggested to be the main source of soluble iron in volcanic ash upon contact with sea water .…”

“…In the surface ocean, however, the soluble species on the ash surface are suggested to be the main source of iron altering the marine biogeochemistry (Hamme et al, 2010;Duggen et al, 2010;Achterberg et al, 2013;Censi et al, 2010). Solubility of iron in airborne particles (e.g., mineral dust) is known to be strongly linked to its chemical speciation and mineralogy (Schroth et al, 2009;Journet et al, 2008).…”