title: Historical records of mercury in southern latitudes over 1600 years: Lake Futalaufquen, Northern Patagonia.
abstract: Mercury is released to the environment from natural and anthropogenic sources, and through atmospheric transport is distributed globally. Lake Futalaufquen (42.8°S) is an oligotrophic lake located in Los Alerces National Park (Northern Patagonia), providing a remote and unpolluted study system. A lacustrine sedimentary sequence revealed 1600 years of Hg deposition, identifying natural baselines and marked peaks not correlated with long-range atmospheric transport. Organic matter and catchment erosion were discarded as Hg drivers. Natural background, pre-1300 CE Hg concentrations, ranged between 27 and 47 ng g(-1) (accumulation rates from 8 to 15μg m(-2) y(-1)). From 1300 CE on, the Hg background profile did not follow the generally increasing Hg pattern observed in both Southern and Northern Hemisphere since pre-industrial times. It was not until the last century that a 1.6-fold increase is observed in the Hg accumulation rate, considered among the lowest increments in southern South America. Noteworthy local/regional sources of Hg for this area, along with global transport, are forest fires and volcanic activity. Between approx. 1340 and 1510 CE, sharp increase in Hg concentration and accumulation rate (up to 204 ng g(-1) and 51 μg m(-2) y(-1), respectively) were clearly associated with extended fire episodes. Furthermore, high Hg peaks during the last 300 years were associated with volcanic eruptions in northernmost Patagonia together with fairly irregular fire episodes, caused by anthropogenic burning by settling population in the Andes.
authors.affiliation: Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. Electronic address: romina@cab.cnea.gov.ar.
authors.forename: Romina
authors.initials: R
authors.lastname: Daga
authors.affiliation: Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche, Argentina.
authors.forename: Sergio
authors.initials: S
authors.lastname: Ribeiro Guevara
authors.affiliation: Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
authors.forename: Majda
authors.initials: M
authors.lastname: Pavlin
authors.affiliation: Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rizzo
authors.affiliation: Jožef Stefan Institute, 1000 Ljubljana, Slovenia; Faculty of Environmental Sciences, University of Nova Gorica, 5000 Nova Gorica, Slovenia.
authors.forename: Sonja
authors.initials: S
authors.lastname: Lojen
authors.affiliation: Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
authors.forename: Polona
authors.initials: P
authors.lastname: Vreča
authors.affiliation: Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
authors.forename: Milena
authors.initials: M
authors.lastname: Horvat
authors.affiliation: Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche, Argentina; Instituto Balseiro, UNCu, Argentina.
authors.forename: María
authors.initials: M
authors.lastname: Arribére
keywords: Argentina; Atmospheric deposition; Fires; Global pollutant; Lakes; Volcanism