title: Dry deposition and heavy acid loading in the vicinity of Masaya Volcano, a major sulfur and chlorine source in Nicaragua.
abstract: Certain volcanoes constitute the world's largest sources of SO2, HCl, and HF emissions and contribute significantly to regional acid deposition. However, the impact of volcanic acid emissions to nearby ecosystems remain poorly documented. In this paper, the spatial pattern of acid dry depositions was monitored within 44 km of Masaya Volcano, Nicaragua, with a network of sulfation plates. Measured SO2 deposition rates were <2-791 mg m(-2) day(-1). The plates also collected the dry deposition of HCI at rates of <1-297 mg m(-2) day(-1). A similar deposition velocity Vd (gas transfer) of 1.6 +/- 0.8 cm/s was calculated for SO2 and HCl above the plate surfaces. Quantities of SO2 and HCI deposited daily within the area surveyed amounted to 1.5 x 10(8) g and 5.7 x 10(7) g, respectively, which correspond to about 10% of the total SO2 and HCl released by the volcano. These depositions may generate an equivalent hydrogen flux ranging from <1 to 30 mg m(-2) day(-1). Our results demonstrate that volcano emissions can dramatically affect acid deposition downwind and in turn cause extreme acid loading of the local ecosystems. This study opens exciting prospects for investigating the sensivity of volcanic ash soils to acid inputs.
authors.affiliation: Unité des Sciences du Sol, Université Catholique de Louvain, Louvain-la-Neuve, Belgium. delmelle@pedo.ucl.ac.be
authors.forename: P
authors.initials: P
authors.lastname: Delmelle
authors.forename: J
authors.initials: J
authors.lastname: Stix
authors.forename: C P
authors.initials: CP
authors.lastname: Bourque
authors.forename: P J
authors.initials: PJ
authors.lastname: Baxter
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Alvarez
authors.forename: J
authors.initials: J
authors.lastname: Barquero
mesh_terms: D015258:Acid Rain; D000392:Air Movements; D017753:Ecosystem; D004784:Environmental Monitoring; D006851:Hydrochloric Acid / Q000032:analysis*; D006859:Hydrogen / Q000737:chemistry; D009527:Nicaragua; D013458:Sulfur Dioxide / Q000032:analysis*; D018707:Volcanic Eruptions
chemical_list: D015258:Acid Rain; D013458:Sulfur Dioxide; D006859:Hydrogen; D006851:Hydrochloric Acid