Biogeochemical Characteristics of Earth's Volcanic Permafrost: An Analog of Extraterrestrial Environments

This article describes a study of frozen volcanic deposits collected from volcanoes Tolbachik and Bezymianny on the Kamchatka Peninsula, Russia, and Deception Island volcano, Antarctica. In addition, we studied suprasnow ash layers deposited after the 2007 eruptions of volcanoes Shiveluch and Bezymianny on Kamchatka. The main objectives were to characterize the presence and survivability of thermophilic microorganisms in perennially frozen volcanic deposits. As opposed to permafrost from the polar regions, viable thermophiles were detected in volcanic permafrost by cultivation, microscopy, and sequencing. In the permafrost of Tolbachik volcano, we observed methane formation by both psychrophilic and thermophilic methanogenic archaea, while at 37°C, methane production was noticeably lower. Thermophilic bacteria isolated from volcanic permafrost from the Deception Island were 99.93% related to Geobacillus stearothermophilus. Our data showed biological sulfur reduction to sulfide at 85°C and even at 130°C, where hyperthermophilic archaea of the genus Thermoproteus were registered. Sequences of hyperthermophilic bacteria of the genus Caldicellulosiruptor were discovered in clone libraries from fresh volcanic ash deposited on snow. Microorganisms found in volcanic terrestrial permafrost may serve as a model for the alien inhabitants of Mars, a cryogenic planet with numerous volcanoes. Thermophiles and hyperthermophiles and their metabolic processes represent a guideline for the future exploration missions on Mars.

Fifty years of volcanic mercury emission research: Knowledge gaps and future directions

Volcanism is a potentially important natural source of mercury (Hg) to the environment. However, its impact on the global Hg cycle remains poorly understood despite advances over the last five decades. This represents a major uncertainty in our understanding of the relative contributions of natural and anthropogenic Hg sources to the global atmosphere. This uncertainty, in turn, impacts evaluation of the effectiveness of policies to mitigate the impact of anthropogenic Hg on the environment. Here we critically review recent progress in volcanic Hg emission research, including advances in sampling methods and understanding of the post-emission behavior of Hg in the atmosphere. Our statistical analysis of the limited available data shows that the plumes of non-arc volcanoes exhibit significantly higher Hg concentrations than arc volcanoes, yet the latter emit 3-fold higher Hg fluxes on average. Arc volcanism also dominates volcanic gas emissions globally, indicating that arc volcanoes should be a priority for future Hg emission research. We explore several methodological challenges that continue to hinder progress in quantifying global volcanic Hg emissions, and discuss the importance of longer time-frame data collection to capture temporal variations in emissions. Recommendations are proposed for working toward a more accurate assessment of the global volcanic Hg flux. A detailed summary of all published volcanic Hg emissions data worldwide is also presented as a reference tool for future work.

Human survival in volcanic eruptions: Thermal injuries in pyroclastic surges, their causes, prognosis and emergency management

This study of burns patients from two eruptions of Merapi volcano, Java, in 1994 and 2010, is the first detailed analysis to be reported of thermal injuries in a large series of hospitalised victims of pyroclastic surges, one of the most devastating phenomena in explosive eruptions. Emergency planners in volcanic crises in populated areas have to integrate the health sector into disaster management and be aware of the nature of the surge impacts and the types of burns victims to be expected in a worst scenario, potentially in numbers and in severity that would overwhelm normal treatment facilities. In our series, 106 patients from the two eruptions were treated in the same major hospital in Yogyakarta and a third of these survived. Seventy-eight per cent were admitted with over 40% TBSA (total body surface area) burns and around 80% of patients were suspected of having at least some degree of inhalation injury as well. Thirty five patients suffered over 80% TBSA burns and only one of these survived. Crucially, 45% of patients were in the 40-79% TBSA range, with most suspected of suffering from inhalation injury, for whom survival was most dependent on the hospital treatment they received. After reviewing the evidence from recent major eruptions and outlining the thermal hazards of surges, we relate the type and severity of the injuries of these patients to the temperatures and dynamics of the pyroclastic surges, as derived from the environmental impacts and associated eruption processes evaluated in our field surveys and interviews conducted by our multi-disciplinary team. Effective warnings, adequate evacuation measures, and political will are all essential in volcanic crises in populated areas to prevent future catastrophes on this scale.

Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): part 1--major and trace element composition

Active biomonitoring using moss-bags was applied to an active volcanic environment for the first time. Bioaccumulation originating from atmospheric deposition was evaluated by exposing mixtures of washed and air-dried mosses (Sphagnum species) at 24 sites on Mt. Etna volcano (Italy). Concentrations of major and a large suite of trace elements were analysed by inductively coupled mass and optical spectrometry (ICP-MS and ICP-OES) after total acid digestion. Of the 49 elements analysed those which closely reflect summit volcanic emissions were S, Tl, Bi, Se, Cd, As, Cu, B, Na, Fe, Al. Enrichment factors and cluster analysis allowed clear distinction between volcanogenic, geogenic and anthropogenic inputs that affect the local atmospheric deposition. This study demonstrates that active biomonitoring with moss-bags is a suitable and robust technique for implementing inexpensive monitoring in scarcely accessible and harsh volcanic environments, giving time-averaged quantitative results of the local exposure to volcanic emissions. This task is especially important in the study area because the summit area of Mt. Etna is visited by nearly one hundred thousand tourists each year who are exposed to potentially harmful volcanic emissions.