How to build a legacy of scientific leadership: the HR formula PROF. JULIA HAMMER, PHD1, LESLIE BAKER2, JENNI BARCLAY3, MICHAEL R. CARROLL4, MICHELLE COOMBS5, ELIZABETH COTTRELL6, NICHOLAS J DYGERT7, LINDA ELKINS-TANTON8, EMILY FIRST9, JAMES GARDNER10, DAVID GOLDSBY11, JAMES GREENWOOD12, MARIE JOHNSON13, MIKE KRAWCZYNSKI14, CHARLES MANDEVILLE15, MOLLY MCCANTA16, MICHELLE E. MINITTI17, WILLIAM NELSON18, TABB PRISSEL19, DINA VENEZKY20, CATHERINE WEITZ21 AND DIANE WOODRUFF22 1University of Hawaiʻi 2University of Idaho 3University of East Anglia 4Camerino University 5U.S. Geological Survey 6National Museum of Natural History, Smithsonian Institution 7University of Tennessee, Knoxville 8Arizona State University 9Cornell University 10University of Texas at Austin 11University of Pennsylvania 12Wesleyan University 13Cal State Fullerton 14Washington University in St. Louis 15US Geological Survey 16University of Tennessee at Knoxville 17Framework, Silver Spring 18University of Hawaii at Manoa 19NASA 20Smith College 21Planetary Science Institute 22Anadarko Petroleum Company Presenting Author: jhammer@hawaii.edu

We summarize major findings and best-practice recommendations from three Volcano Observatory Best Practices (VOBP) workshops, which were held in 2011, 2013 and 2016. The workshops brought together representatives from the majority of the world’s volcano observatories for the purpose of sharing information on the operation and practice of these institutions and making best practice recommendations. The first workshop focused on eruption forecasting, the second on hazard communication, and the third on long-term hazard assessment. Subsequent VOBP workshops will address additional issues of broad interest to the international volcano observatory community. The objective of VOBP is to develop synergy among volcano hazards programs and their observatories internationally, so as to more rapidly and broadly advance the field of applied volcanology. Each of the workshop summaries presented here include best practice recommendations for consideration by the world’s volcano observatories.

Activity at Augustine Volcano, Alaska, has been characterized by intermediate composition domes, flows, and tephras during the Holocene. Erosive lahars and pyroclastic flows associated with the 2006 eruption revealed large exposures of voluminous rhyolite pumice fall beneath glacial tills; the massive rhyolite deposit is evidence of anomalously large prehistoric eruptions. The rhyolite is petrologically and mineralogically different from more recent eruptive products, with abundant amphibole (calcic amphiboles and cummingtonite) and quartz. Three texturally and chemically distinct lithologies are present. Fe–Ti oxide equilibria suggest temperatures of ~ 765 °C and oxygen fugacities of NNO + 1.5. Melt inclusions indicate that magma representing the stratigraphically lowest lithology was crystallizing at ~ 260 MPa with a contemporary mixed H2O–CO2 fluid phase becoming progressively more H2O-rich. Magma forming the other lithologies crystallized in the presence of this H2O-dominated fluid, as demonstrated by the presence of cummingtonite and little to no CO2 in melt inclusions. Amphibole and quartz–feldspar–melt equilibria models yield results indicating a range of crystallization pressures from ~ 400 MPa to ~ 175 MPa. Apatites and melt inclusions have lower chlorine contents than more recently erupted material at Augustine suggesting that the composition of Augustine's volatile phase has changed over time. Reheating textures in melt inclusions and phenocrysts, as well as the presence of xenocrysts of olivine and clinopyroxene containing mafic melt inclusions, signify the likelihood of mixing and/or mingling of magmas as an eruption trigger. The unique qualities of this Pleistocene rhyolite and the potential hazard of a similarly large eruption in modern times indicate that further study is warranted.

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Decompression experiments (from 400 to 70 MPa) were conducted Lo invesligale sulfur (5) dislaibulion and 5-isotope fraclionalion between basaltic melts and coexisling fluids. Volaffle-bearing [similar to 3 to similar to 7 wt.% water (H2O), similar to 300 to similar to 1200 ppm S,0 to similar to 3600 ppm chlorine (Cl)] basaltic glasses were used as slailing mareLials.The MgO conlent in the melt was effher similar to 1 wt.% (Mg poor basalt.) or similar to 10 wt.% (alkali basalt.) toinvesligale he possible role of compositional changes in basaltic sysLems on fluid -melt distribution of S and S-isoLopes. The experiments were performed in internally heated pressure vessels (IHPV) at 1050"C to 1250 C, variable oxygen fugacities fO(2); ranging from log(fO(2)/bar) similar to QFM to similar to QFM + 4. QFM = quartz-fayalite-magnetite buffer) and at a constant decompression rate (r) of 0.1 MPa/s.The annealing time (t(A)) at final pressure (p) and temperature (T) after decompression was varied from 0 to 5.5 h to study the fluid-melt equilibration process.Sulfur and H2O contents in the melt decreased significantly during decompression, while the Cl contents I emained almost constant. No changes in H2O and Cl content were observed with t(A), while S concentrations decreased slightly with t(A) <2 h; i.e., near-equilibrium fluid-melt conditions were reached within similar to 2 h after decompression, even in experiments performed at the lowest Tot 1050 degrees C. Thus, fluid-melt partitioning coefficients of S (D-S(fl/m)) were determined from experiments with t(A) >= 2 h. The MgO (similar to 1 to similar to 10 wt.%), H2O (similar to 3 to similar to 7 wt.%) and Cl contents (<0.4 wt.') in the melt have no significant effect on LA7-/"'. Consistent with previous studies we found that e" decreased strongly with increasing f02; e.g., at similar to 1200 degrees C D-s(fl/m) approximate to 180 at QTM + 1 and D-s(fl/m) 40 at (2FM 4. A positive correlation was observed between and Tin the range of 1150 to 1250 C at both oxidizing (QEM + 4; DDsfl/m = 52 +/- 27 to 76 +/- 30) and intermediate (QTM + 1.5; DDsfl/m 94 +/- 20 to 209 +/- 80) reclox conditions. Data compiled at 1050 C and relatively reducing conditions ( -QTM; DDsfl/m 58 +/- 18) indicate that the trends may be extrapolated to lower T, at least for intermediate to reducing conditions (-(2FM + 1.5 to -WM).The S-isotope composition in glasses of selected samples was measured by secondary ion mass spectrometry (SIMS). Gas-melt isotopic fractionation factors (an r) were calculated via mass balance. At 1200 degrees C an average r of 0.9981 - 0.0015 was determined for oxidizing conditions (-QFM + 4), while an average an r of 1.0025 0.0010 was found for fairly reducing conditions (-QFM + 1). Furthermore, at lower T (1050 C) an average ciql r, of 1.0037 0.0009 was determined for reducing conditions (-QFM). The data showed that equilibrium fractionation effects during closed-system degassing of basaltic melts at T relevant for magmatic systems (1050 to 1250 C) can induce a S-isotope fluid-melt fractionation of about + LI& in relatively reduced systems and of about 2% in relatively oxidized systems.The reported experimental results are valuable for the interpretation of S and 5-isotope signature in magmatic systems (e.g., in volcanic gasses or melt inclusions) and will help to elucidate, for instance, volatile transport processes across subduction zones and Earth's S cycle. (c) 2014 Elsevier B.V. All rights reserved.

1. An introduction to global volcanic hazard and risk S. C. Loughlin, C. Vye-Brown, R. S. J. Sparks, S. K. Brown, J. Barclay, E. Calder, E. Cottrell, G. Jolly, J.-C. Komorowski, C. Mandeville, C. Newhall, J. Palma, S. Potter, G. Valentine, B. Baptie, J. Biggs, H. S. Crosweller, E. Ilyinskaya, C. Kilburn, K. Mee and M. Pritchard 2. Global volcanic hazard and risk S. K. Brown, S. C. Loughlin, R. S. J. Sparks, C. Vye-Brown, J. Barclay, E. Calder, E. Cottrell, G. Jolly, J.-C. Komorowski, C. Mandeville, C. Newhall, J. Palma, S. Potter, G. Valentine, B. Baptie, J. Biggs, H. S. Crosweller, E. Ilyinskaya, C. Kilburn, K. Mee and M. Pritchard 3. Volcanic ash fall hazard and risk S. F. Jenkins, T. M. Wilson, C. Magill, V. Miller, C. Stewart, R. Blong, W. Marzocchi, M. Boulton, C. Bonadonna and A. Costa 4. Populations around Holocene volcanoes and development of a Population Exposure Index S. K. Brown, M. R. Auker and R. S. J. Sparks 5. An integrated approach to Determining Volcanic Risk in Auckland, New Zealand: the multidisciplinary DEVORA project N. I. Deligne, J. M. Lindsay and E. Smid 6. Tephra fall hazard for the Neapolitan area W. Marzocchi, J. Selva, A. Costa, L. Sandri, R. Tonini and G. Macedonio 7. Eruptions and lahars of Mount Pinatubo, 1991-2000 C. G. Newhall and R. Solidum 8. Improving crisis decision-making at times of uncertain volcanic unrest (Guadeloupe, 1976) J.-C. Komorowski, T. Hincks, R. S. J. Sparks, W. Aspinall and CASAVA ANR project consortium 9. Forecasting the November 2010 eruption of Merapi, Indonesia J. Pallister and Surono 10. The importance of communication in hazard zone areas: case study during and after 2010 Merapi eruption, Indonesia S. Andreastuti, J. Subandriyo, S. Sumarti and D. Sayudi 11. Nyiragongo (Democratic Republic of Congo), January 2002: a major eruption in the midst of a complex humanitarian emergency J.-C. Komorowski and K. Karume 12. Volcanic ash fall impacts T. M. Wilson, S. F. Jenkins and C. Stewart 13. Health impacts of volcanic eruptions C. Horwell, P. Baxter and R. Kamanyire 14. Volcanoes and the aviation industry P. W. Webley 15. The role of volcano observatories in risk reduction G. Jolly 16. Developing effective communication tools for volcanic hazards in New Zealand, using social science G. Leonard and S. Potter 17. Volcano monitoring from space M. Poland 18. Volcanic unrest and short-term forecasting capacity J. Gottsmann 19. Global monitoring capacity: development of the Global Volcano Research and Monitoring Institutions Database and analysis of monitoring in Latin America N. Ortiz Guerrero, S. K. Brown, H. Delgado Granados and C. Lombana Criollo 20. Volcanic hazard maps E. Calder, K. Wagner and S. E. Ogburn 21. Risk assessment case history: the Soufriere Hills Volcano, Montserrat W. Aspinall and G. Wadge 22. Development of a new global Volcanic Hazard Index (VHI) M. R. Auker, R. S. J. Sparks, S. F. Jenkins, S. K. Brown, W. Aspinall, N. I. Deligne, G. Jolly, S. C. Loughlin, W. Marzocchi, C. G. Newhall and J. L. Palma 23. Global distribution of volcanic threat S. K. Brown, R. S. J. Sparks and S. F. Jenkins 24. Scientific communication of uncertainty during volcanic emergencies J. Marti 25. Volcano Disaster Assistance Program: preventing volcanic crises from becoming disasters and advancing science diplomacy J. Pallister 26. Communities coping with uncertainty and reducing their risk: the collaborative monitoring and management of volcanic activity with the Vigias of Tungurahua J. Stone, J. Barclay, P. Ramon, P. Mothes and STREVA.

Glasses produced from decompression experiments conducted by Fiege et al. (2014a) were used to investigate the fractionation of sulfur isotopes between fluid and andesitic melt upon magma degassing. Starting materials were synthetic glasses with a composition close to a Krakatau dacitic andesite. The glasses contained 4.55–7.95wt% H2O, ∼140 to 2700ppm sulfur (S), and 0–1000ppm chlorine (Cl). The experiments were carried out in internally heated pressure vessels (IHPV) at 1030°C and oxygen fugacities (fO2) ranging from QFM+0.8 log units up to QFM+4.2 log units (QFM: quartz–fayalite–magnetite buffer). The decompression experiments were conducted by releasing pressure (P) continuously from ∼400MPa to final P of 150, 100, 70 and 30MPa. The decompression rate (r) ranged from 0.01 to 0.17MPa/s. The samples were annealed for 0–72h (annealing time, tA) at the final P and quenched rapidly from 1030°C to room temperature (T).

Young basaltic back-arc volcanoes occur east of the main Andes chain at about 37.5°–39°S in the Loncopue graben, Province of Neuquen, Argentina. These olivine-rich basalts and trachybasalts have up to 8% MgO, with high Ni and Cr contents, but highly variable incompatible element concentrations. Mafic lava flows and cinder cones at the southern end of the graben lack phenocrystic plagioclase. The northern samples have relative Ta–Nb depletions and K, Pb and LREE enrichment. These samples strongly resemble rocks of the nearby arc volcanoes Copahue and Caviahue, including their Fe–Ti enrichment relative to the main Andes arc rocks. The Sr, Nd and Pb isotope ratios show that the source regions of these back-arc basalts are enriched in subducted components that were depleted in the aqueous mobile elements such as Cs, Sr and Ba as a result of prior extractions from the subducted complex below the main arc. Some mafic flows show slightly low 206Pb/204Pb and 143Nd/144Nd values as well as incompatible trace element ratios similar to southern Patagonia plateau back-arc basalts, suggesting contributions from an EM1 mantle source. Geothermometry and barometry suggest that the basalts crystallized and fractionated small amounts of olivine and spinel at ∼35km depth at temperatures of 1170–1220°C, at about QFM+0.5 to QFM+1 with 1–2% H2O, and then rose rapidly to the surface. The Loncopue graben back-arc basalts are transitional in composition between the South Patagonia back-arc plateau basalts and the Caviahue and Copahue arc volcanoes to the northwest. The EM1 source endmember is possibly the subcontinental lithospheric mantle. Strong variations in incompatible element enrichment and isotopic compositions between closely spaced cinder cones and lava flows suggest a heterogeneous mantle source for the Loncopue graben volcanics.

The petrology and geochemistry of 2006 eruptive products of Augustine Volcano, Alaska, have been investigated through analyses of whole-rock samples, phenocrysts, silicate melt inclusions, and matrix glasses to constrain processes of magma evolution, eruption, and degassing. Particular attention was directed toward the concentrations and geochemical relationships involving the magmatic volatile components H2O, CO2, S, and Cl. The analytical results for 2006 samples have been integrated with data for samples of Pleistocene basalt, prehistoric andesites, and 1986 andesites from Augustine to provide a broad view of volatile behavior in Augustine magmas. The observation of generally similar geochemical features for this range of eruptions indicates that magmatic and volatile degassing processes have been relatively consistent during the past 2,100 years. Augustine andesites range from low-silica to high-silica compositions and contain phenocrysts of plagioclase, orthopyroxene, and clinopyroxene, with lesser olivine, amphiboles, iron-titanium oxides, and apatite. The groundmass varies from strongly crystallized and/or oxidized to comparatively clear, microlite-poor vesicular glass. Coexisting iron-titanium oxides of 2006 rock samples, which are generally consistent with those of prior eruptive materials, indicate ƒO2 values of approximately NNO+1.5 to NNO+2.5 and oxide crystallization temperatures of 835 to 1,052°C. The compositions of matrix and melt-inclusion glasses range from rhyodacite to rhyolite and show relationships that reflect magma evolution involving fractional crystallization and multiple stages of mingling and/or mixing. In particular, melt inclusions of low-silica andesites express mixing of magmas with more widely varying compositions, than do melt inclusions of high-silica andesites and dacites. The melt inclusions of 2006, 1986, and prehistoric andesites contain moderate to high concentrations of H2O and Cl and lesser CO2 and SO2. Comparing the abundances of H2O, CO2, and Cl in these melt inclusions with experimentally established volatile solubilities for felsic melts indicates that the 2006 and prehistoric samples are most consistent with the ascent of fluid-saturated magmas containing 1 weight percent of H2O-enriched vapor under closed-system conditions and that pressures of volatile phase exsolution range from 150 to less than 20 MPa. This closed-system behavior was maintained to quite shallow depths prior to eruption, and this pressure range is consistent with constraints derived from 2006 geodetic measurements indicating magma storage and crystallization at 4 to 6 km and upwards to near-surface depths. The magmatic fluids were relatively oxidizing and included H2O-enriched and HCl-, H2S-, S2-, and SO2 ± CO2-bearing vapors; hydrosaline aqueous liquids largely enriched in Cl-, SO42-, alkalis, and H2O; and moderately saline, H2O-poor liquids containing Cl-, SO42-, and alkali elements.

Micro-Raman spectroscopy, even though a very promising technique, is not still routinely applied to analyse H2O in silicate glasses. The accuracy of Raman water determinations critically depends on the capability to predict and take into account both the matrix effects (bulk glass composition) and the analytical conditions on band intensities. On the other hand, micro-Fourier transform infrared spectroscopy is commonly used to measure the hydrous absorbing species (e.g., hydroxyl OH− and molecular H2O) in natural glasses, but requires critical assumptions for the study of crystal-hosted glasses. Here, we quantify for the first time the matrix effect of Raman external calibration procedures for the quantification of the total H2O content (H2OT=OH−+H2Om) in natural silicate glasses. The procedures are based on the calibration of either the absolute (external calibration) or scaled (parameterisation) intensity of the 3550cm−1 band. A total of 67 mafic (basanite, basalt) and intermediate (andesite) glasses hosted in olivines, having between 0.2 and 4.8wt% of H2O, was analysed. Our new dataset demonstrates, for given water content, the height (intensity) of Raman H2OT band depends on glass density, reflectance and water environment. Hence this matrix effect must be considered in the quantification of H2O by Raman spectroscopy irrespective of the procedure, whereas the parameterisation mainly helps to predict and verify the self-consistency of the Raman results. In addition, to validate the capability of the micro-Raman to accurately determine the H2O content of multicomponent aluminosilicate glasses, a subset of 23 glasses was analysed by both micro-Raman and micro-FTIR spectroscopy using the band at 3550cm−1. We provide new FTIR absorptivity coefficients (ε3550) for basalt (62.80±0.8Lmol−1cm−1) and basanite (43.96±0.6Lmol−1cm−1). These values, together with an exhaustive review of literature data, confirm the non-linear decline of the FTIR absorptivity coefficient (ε3550) as the glass depolymerisation increases. We demonstrate the good agreement between micro-FTIR and micro-Raman determination of H2O in silicate glasses when the matrix effects are properly considered.

Sulfur is a widely distributed element on Earth and in the solar system. Its multiple valence states (S2- to S6+) allow it to participate in numerous geochemical and biochemical processes. It may be one of the light elements in the Earth's core and may have been crucial in core formation. Sulfur is an essential component in all life on Earth and likely supported earliest life. Sulfur geochemistry is used to understand the early evolution of Earth's atmosphere and hydrosphere, and serves as a monitor of volcanic SO2 and H2S and as a tracer of anthropogenic sources of sulfur. Recent advances in the use of multiple sulfur isotopes (S-32, S-33, S-34, and S-36) and in situ isotopic measurements will help to develop sulfur stable isotopes as a vital tracer in the Earth and planetary sciences and will provide applications for understanding inorganic and biogenic processes.

Sulfur is a ubiquitous element whose variable valence states (S2-, S-0, S4+, S6+) allow it to participate in a wide variety of geochemical and biogeochemical processes. Depending on its redox state and controlling species, sulfur dissolved in magma may be fractionated into a water-rich phase and sulfur-bearing minerals. Retrieving information on the original sulfur abundance and isotopic signature of a magma is challenging and requires deciphering the different processes that may have operated during its evolution en route to the surface. Advances made in thermodynamic modeling, experimentation on sulfur solubility and diffusion in silicate melts, and microanalytical techniques for probing sulfur's speciation and isotopic signature at the micrometer scale are providing an outstanding picture of sulfur evolution in magmas.