DOCSLIB.ORG

Fluxes of Volatiles (H2O, CO2, N2, Cl, F) from Arc Volcanoes INVITED

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fluxes of Volatiles (H2O, CO2, N2, Cl, F) from Arc Volcanoes INVITED Geochemical Journal, Vol. 42, pp. 21 to 38, 2008 INVITED REVIEW Fluxes of volatiles (H2O, CO2, N2, Cl, F) from arc volcanoes TOBIAS P. FISCHER* Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131-1116, U.S.A. (Received June 6, 2007; Accepted September 10, 2007) This review gives an overview of the estimates of volatile emissions from arc and mid-ocean ridge volcanoes to the atmosphere and hydrosphere with particular focus on H2O, CO2, N2, Cl and F. The gas compositions of high temperature ° (>500 C) fumaroles are compiled and used to derive magmatic H2O/SO2, CO2/SO2, HCl/SO2 and HF/SO2 ratios on an arc- by-arc basis to obtain new estimates of major volatile fluxes from arcs globally. The estimate of F flux from arcs is two orders of magnitude smaller than the amount of F released from mid ocean ridges whereas the arc Cl flux exceeds the ridge flux. An important observation is that globally the water budget of subduction zones seems to be balanced and the amount of water degassed through arc volcanism is within the estimates of the amount of water released from the slab below the volcanic front. Recent work that focused on the Central American arc shows that detailed knowledge of the subduction input compositions, coupled with gas emission studies is critical to further constrain the fate of volatiles during the subduction processes. Keywords: volcanoes, fluxes, water, halogens, sources Although a large number of SO flux measurements INTRODUCTION 2 using the Correlation Spectrometer (COSPEC) have been Volatiles are transferred from the Earth’s mantle to made since the instrument was first pointed at a volcano the atmosphere, the hydrosphere and crust through erup- (Mt. Mihara, Japan) by Moffat et al. (1972) and Stoiber’s tive and non-eruptive subaerial and submarine volcanic first estimate of global volcanic SO2 (Stoiber and Jepsen, activity. Volatiles are also recycled from the surface back 1973), there are still large data gaps particularly for vol- to the Earth’s mantle via subduction. Quantification of canoes in remote areas. This is certainly improving with volatile degassing through volcanoes and estimation of better satellite remote sensing technology (Bluth et al., their source components (mantle vs. surface) bears fun- 1993; Khokhar et al., 2005) and smaller, cheaper ground- damental information on a number of issues in the Earth based instruments such as the mini DOAS (Galle et al., sciences ranging from the evolution of the Earth’s atmos- 2002). Because SO2 is the easiest gas to measure remotely phere to the potential origin of geochemical (high abundance in the plume, low atmospheric back- heterogeneities in the mantle. Noble gases are a critical ground and strong absorption in the UV), its global vol- part of estimating the fluxes of other volatiles to the at- canic flux has been comparatively well constrained. This mosphere by combining, for example, the mid-ocean ridge is also true for CO2 where recent estimates generally fall 3 3 (MOR) He flux of Craig et al. (1975) with the CO2/ He within the range of earlier ones. The flux estimates of ratio of oceanic basalt to arrive at MOR CO2 flux (Marty other major volatiles, still vary by several orders of mag- and Jambon, 1987). The application of noble gases to nitude (H2O) or have not received much attention (HCl, constraining the sources and fluxes of volatiles from sub- HF). duction zones has recently been reviewed by Hilton et al. The purpose of this review is to provide the reader (2002). Deriving subduction volatile fluxes from melt with an overview of the work that has been done in the inclusion studies combined with magma emplacement field of volatile flux estimates from volcanoes. Gas chem- rates has recently been reviewed by Wallace (2005) and istry from high temperature (>500°C), magmatic Kerrick (2001) reviewed the present and past fumaroles world-wide (1970’s to 2002) is compiled to nonanthropogenic CO2 flux from the solid Earth. determine representative, magmatic H2O/SO2, CO2/SO2, N2/SO2, HCl/SO2 and HF/SO2 ratios on an arc-by-arc basis for new estimates of H2O, CO2, N2, HCl and HF *E-mail address: [email protected] fluxes. The water flux, in particular, is discussed in more Copyright © 2008 by The Geochemical Society of Japan. detail with implications for the water cycle in subduction 21 90° 145° 160° 105° 50° Kamchatka 30° Alaska Cascades Ryuku Kuril Is. Aleutian Japan Izu-Bonin Central America Colombia 0° Banda Java Kermadec New Zealand 30° 60° Fig. 1. Arcs that have high temperature (>400°) fumaroles with data compiled in Table 1. Italy is not shown. Modified from Hilton et al. (2002). zones. After discussing global volatile emissions, the re- volatile ratios to arrive at fluxes of gases other than SO2. view focuses on some recent studies done in the Central Extrapolation of both types of estimates to global emis- American arc, that provide tighter constrains on both the sions is still burdened with large uncertainties and ac- input into the subduction zone and the output through counting for extreme point source emissions, such as the volcanoes. 18 × 106 tons emitted from Miyakejima volcano, Japan from 2000 to 2003 (Kazahaya et al., 2004) remains a chal- lenge. This is true particularly for species other than SO2, GLOBAL VOLCANIC VOLATILE FLUXES 3 CO2 and He which are affected by hydrothermal or Quantifying volcanic volatile fluxes, in particular for seawater contributions (H2O, Cl and F), air contamina- greenhouse gases such as CO2, is critical for studies that tion (N2, Ar, Ne), or are extremely variable in volcanic are concerned with global element cycles. Berner and emissions (H2, CH4 and CO). Despite these uncertainties, Lasaga, (1989) note that calculating the rate of degassing current knowledge of volcanic volatile emissions allows of CO2 due to igneous and metamorphic process is a ma- for careful incorporation of these data into global ele- jor problem when modeling the global carbon cycle. Al- ment cycles. though CO2 degassing from volcanic arcs, mid-ocean ridges and to a lesser extent plumes is now relatively well Volatile fluxes from volcanic arcs constrained (within a factor of about two), the CO2 flux Correlation spectrometers (COSPEC) are the stand- from continental rifts remains largely unknown. Most ard instruments used to measure volcanic SO2 fluxes from global volcanic volatile flux estimates rely a) on magma volcanoes. These instruments were first developed in the emplacement rates, degrees of melting coupled with 1960s to measure pollution emitted from industrial and known or estimated volatile abundances in the source re- chemical plants (as SO2 and NO2), but their utility for gion of the melts or b) on sporadic point measurements volcanic flux measurements was recognised shortly there- of gas emissions rates (SO2) from erupting or passively after. The COSPEC was first used at Mt. Mihara volcano, degassing volcanoes coupled with measured or estimated Japan, in April 1971. Today, COSPEC measurements re- 22 T. P. Fischer Table 1. Gas chemistry of high temperature fumaroles world-wide (mol% total gas) and gas ratios used in flux calculations Volcano Mount St Helens Augustine Momotombo Momotombo Poas Galeras Galeras Arc Cascades Aleutians C. America C. America C. America N. South Am. N. South Am. T (°C) 710 870 844 747 940 358 642 Date 1982 May-2002 1981 Feb-1993 1991 Ref. Symonds et al., 1994 Symonds et al., 1990 Giggenbach, 1996 Elkins et al., 2006 Rowe et al., 1992 Goff and McMurtry, 2000 Giggenbach, 1996 H2O (%) 98.9 84.77 95.05 96.25 95 89.6 91.5 CO2 0.88 2.27 2.38 2.53234906 1.35 7.8312 5.98 SO2 0.27 6.98 0.7 0.2334981 2.83 1.2792 0.8415 H2S 0.49 0.53976 0.5725 HCl 0.15 1.01 0.35 0.52757577 0.38 0.3848 0.716 HF 0.03 0.086 0.029 0.03838822 0.015 0.038064 0.062 H2 0.4 0.54 0.87 0.35167164 0.9 0.23712 0.285 CH4 0.00003 <0.00003 0.0004 0 CO 0.003 0.016 0.025 0.01121797 0.012 0.0136 NH3 7.2133E-05 0.0029744 N2 0.12 0.11 0.08 0.05528918 0.1 0.047944 0.041 Ar 0.000025 0.0025 0.00010983 9.36E-05 O2 <0.00005 0 He 0.00005 0.000156 0.0003 Total 100.75 95.78 99.97 100.00 100.58 99.96 100.01 CO2/SO2 3.259 0.325 3.400 10.845 0.477 6.122 7.106 median 3.250 0.320 3.400 6.614 mean 3.250 4.907 6.614 STD 3.086 0.492 HCl/SO2 0.556 0.145 0.500 2.259 0.134 0.301 0.851 median 1.197 0.576 mean 3.250 0.965 0.576 STD 0.656 0.275 N /SO 0.441 0.001 0.114 0.218 0.035 0.035 0.049 Volatile fluxesfromvolcanoesVolatile 23 2, exc 2 median 0.127 0.042 mean 0.441 0.123 0.042 STD 0.053 0.007 H2O/SO2 366.3 12.1 135.8 412.2 33.6 70.0 108.7 median 0.320 135.7 89.3 mean 193.8 89.4 STD 113.1 19.3 HF/SO2 0.111 0.012 0.041 0.164 0.005 0.029 0.073 median 0.320 0.041 0.052 mean 0.070 0.052 STD 0.048 0.022 24 Fischer P. T. Table 1. (continued) Volcano Satsuma Iwojima Satsuma Iwojima Usu Showa Shinzan Tokachi Unzen Arc Japan Japan Japan Japan Japan Japan T (°C) 885 880 690 800 505 818 Date Nov-93 1992 Ref.
Load more

Recommended publications
  • Poas Volcano, Costa Rica: Geology of the Summit Region and Spatial and Temporal Variations Among the Most Recent Lavas
    Journal of Volcanology and Geothermal Research, 33 (1987) 131-146 131 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands POAS VOLCANO, COSTA RICA: GEOLOGY OF THE SUMMIT REGION AND SPATIAL AND TEMPORAL VARIATIONS AMONG THE MOST RECENT LAVAS JEROME T. PROSSER 1'* and MICHAEL J. CARR 2 1Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, U.S.A. 2Department of Geological Sciences, Rutgers University, New Brunswick, NJ 08903, U.S.A. (Received November 25, 1986 ) Abstract Prosser, J.T. and Carr, M.J., 1987. Po~s volcano, Costa Rica: Geology of the summit region and spatial and temporal variations among the most recent lavas. In: S.N. Williams and M.J. Carr (Editors), Richard E. Stoiber 75th Birth- day Volume. J. Volcanol. Geotherm. Res., 33: 131-146. The recent eruptive history of Po~s volcano is described here on the basis of field mapping of the summit area. This period, which may represent 10 to 20,000 years and less than 10% of the history of the volcano, began with caldera formation. Subsequent events included: composite cone construction, faulting and flank subsidence, flank fissure eruption, and multiple crater collapses. Local and regional structures have controlled the locations of summit vents and flank cinder cones. Chemical compositions of lavas of known stratigraphic position demonstrate temporal magmatic variation at Po~s. Three similar felsic to mafic magmatic sequences occurred at the summit. The first and second sequences were sepa- rated by flank and summit eruptions of a distinct magma batch, enriched in TiO., and P205. The three felsic to mafic sequences appear to be cyclical, and the repeated, similar variations are interpreted as progressive tapping of zoned magma bodies developed repeatedly from a common parent by similar crystal fractionation processes.
    [Show full text]
  • A Constrained 3D Density Model of the Upper Crust from Gravity Data Interpretation for Central Costa Rica
    Hindawi Publishing Corporation International Journal of Geophysics Volume 2010, Article ID 860902, 9 pages doi:10.1155/2010/860902 Research Article A Constrained 3D Density Model of the Upper Crust from Gravity Data Interpretation for Central Costa Rica Oscar H. Lucke,¨ 1 Hans-Jurgen¨ Gotze,¨ 1 and Guillermo E. Alvarado2 1 Institut fur¨ Geowissenschaften Abteilung Geophysik, Christian-Albrechts-Universitat¨ zu Kiel, Otto-Hahn-Platz 1, 24118 Kiel, Germany 2 Instituto Costarricense de Electricidad, Area´ de Amenazas y Auscultacion´ Sismologica´ y Volcanica,´ 1032-100 San Jos´e, Costa Rica Correspondence should be addressed to Oscar H. Lucke,¨ [email protected] Received 30 September 2009; Revised 4 January 2010; Accepted 5 January 2010 Academic Editor: Marek Grad Copyright © 2010 Oscar H. Lucke¨ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The map of complete Bouguer anomaly of Costa Rica shows an elongated NW-SE trending gravity low in the central region. This gravity low coincides with the geographical region known as the Cordillera Volcanica´ Central. It is built by geologic and morpho- tectonic units which consist of Quaternary volcanic edifices. For quantitative interpretation of the sources of the anomaly and the characterization of fluid pathways and reservoirs of arc magmatism, a constrained 3D density model of the upper crust was designed by means of forward modeling. The density model is constrained by simplified surface geology, previously published seismic tomography and P-wave velocity models, which stem from wide-angle refraction seismic, as well as results from methods of direct interpretation of the gravity field obtained for this work.
    [Show full text]
  • Pacific Offshore Record of Plinian Arc Volcanism in Central America: 2
    Article Geochemistry 3 Volume 9, Number 2 Geophysics 8 February 2008 Q02S02, doi:10.1029/2007GC001791 GeosystemsG G ISSN: 1525-2027 AN ELECTRONIC JOURNAL OF THE EARTH SCIENCES Published by AGU and the Geochemical Society Pacific offshore record of plinian arc volcanism in Central America: 2. Tephra volumes and erupted masses S. Kutterolf SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany ([email protected]) A. Freundt SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany W. Pere´z SFB574 at Kiel University/IFM-GEOMAR, Wischhofstrasse 1-3, D-24148 Kiel, Germany [1] Sediment gravity cores collected from the Pacific seafloor offshore Central America contain numerous distal ash layers from plinian-type eruptions at the Central American Volcanic Arc dating back to more than 200 ka. In part 1 of this contribution we have correlated many of those ash layers between cores and with 26 tephras on land. The marine ash layers cover areas of up to 106 km2 in the Pacific Ocean and represent a major fraction (60–90%) of the erupted tephra volumes because the Pacific coast lies within a few tens of kilometers downwind from the volcanic arc. Combining our own mapping efforts on land and published mapping results with our marine data yields erupted volumes of all major tephras along the arc that range from 1 to 420 km3. Recalculated to erupted magma mass, the widespread tephras account for 65% of the total magma output at the arc.
    [Show full text]
  • USGS Open-File Report 2009-1133, V. 1.2, Table 3
    Table 3. (following pages). Spreadsheet of volcanoes of the world with eruption type assignments for each volcano. [Columns are as follows: A, Catalog of Active Volcanoes of the World (CAVW) volcano identification number; E, volcano name; F, country in which the volcano resides; H, volcano latitude; I, position north or south of the equator (N, north, S, south); K, volcano longitude; L, position east or west of the Greenwich Meridian (E, east, W, west); M, volcano elevation in meters above mean sea level; N, volcano type as defined in the Smithsonian database (Siebert and Simkin, 2002-9); P, eruption type for eruption source parameter assignment, as described in this document. An Excel spreadsheet of this table accompanies this document.] Volcanoes of the World with ESP, v 1.2.xls AE FHIKLMNP 1 NUMBER NAME LOCATION LATITUDE NS LONGITUDE EW ELEV TYPE ERUPTION TYPE 2 0100-01- West Eifel Volc Field Germany 50.17 N 6.85 E 600 Maars S0 3 0100-02- Chaîne des Puys France 45.775 N 2.97 E 1464 Cinder cones M0 4 0100-03- Olot Volc Field Spain 42.17 N 2.53 E 893 Pyroclastic cones M0 5 0100-04- Calatrava Volc Field Spain 38.87 N 4.02 W 1117 Pyroclastic cones M0 6 0101-001 Larderello Italy 43.25 N 10.87 E 500 Explosion craters S0 7 0101-003 Vulsini Italy 42.60 N 11.93 E 800 Caldera S0 8 0101-004 Alban Hills Italy 41.73 N 12.70 E 949 Caldera S0 9 0101-01= Campi Flegrei Italy 40.827 N 14.139 E 458 Caldera S0 10 0101-02= Vesuvius Italy 40.821 N 14.426 E 1281 Somma volcano S2 11 0101-03= Ischia Italy 40.73 N 13.897 E 789 Complex volcano S0 12 0101-041
    [Show full text]
  • Volcanism and Geochemistry in Central America: Progress and Problems M
    Volcanism and Geochemistry in Central America: Progress and Problems M. J. Carr1, M.D. Feigenson1, L. C. Patino2 and J.A. Walker3 1Department of Geological Sciences, Rutgers University 2Department of Geological Sciences, Michigan State University 3Department of Geology and Environmental Geosciences, Northern Illinois University Most Central American volcanoes occur in an impressive volcanic front that trends parallel to the strike of the subducting Cocos Plate. The volcanic front is a chain, made of right-stepping, linear segments, 100 to 300 Km in length. Volcanoes cluster into centers, whose spacing is random but averages about 27 Km. These closely spaced, easily accessible volcanic centers allow mapping of geochemical variations along the volcanic front. Abundant back-arc volcanism in southeast Guatemala and central Honduras allow two cross-arc transects. Several element and isotope ratios (e.g. Ba/La, U/Th, B/La, 10Be/9Be, 87Sr/86Sr) that are thought to signal subducted marine sediments or altered MORB consistently define a chevron pattern along the arc, with its maximum in Nicaragua. Ba/La, a particularly sensitive signal, is 130 at the maximum in Nicaragua but decreases out on the limbs to 40 in Guatemala and 20 in Costa Rica, which is just above the nominal mantle value of 15. This high amplitude regional variation, roughly symmetrical about Nicaragua, contrasts with the near constancy, or small gradient, in several plate tectonic parameters such as convergence rate, age of the subducting Cocos Plate, and thickness and type of subducted sediment. The large geochemical changes over relatively short distances make Central America an important margin for seeking the tectonic causes of geochemical variations; the regional variation has both a high amplitude and structure, including flat areas and gradients.
    [Show full text]
  • La Formación Alto Palomo: Flujos Pumíticos 75
    Revista Geológica de América Central, 30: 73-81, 2004 LA FORMACIÓN ALTO PALOMO: FLUJOS PUMÍTICOS DE LA CORDILLERA VOLCÁNICA CENTRAL, COSTA RICA Adrián Villegas Fonseca Instituto Costarricense de Electricidad, Apdo. 10032-1000, San José Costa Rica [email protected] (Recibido 15/05/03; aceptado 21/09/03) ABSTRACT: The Alto Palomo Formation is divided in two members: Palomo (lower) and Palmitos (upper). Both are composed by pumice lapilli tuffs (pumice pyroclastic flows). There are also lithic or pumice basal brec- cias (co-ignimbritic lag breccias and air fall breccias). At the base of this sequence, there are in some localities thin layers of fine to medium-grained ashes (pyroclastic surges). The two members can be recognized according to their compositional differences: biotite and accretional lapilli in Palmitos Member and absence of them in Palomo Member. The distribution of the latter suggests its origin in La Picada Caldera. The distribution of com- ponents in Palmitos Member shows a strong control by paleo-valleys (observed thickness ≤ 100 m) around La Vieja river. The occurrence of basal lithic and pumice breccias around this locality, suggests that this member originated from Chocosuela Caldera. Platanar volcano built its edifice on its southern rim. Keywords: Central Volcanic Range, pumice flow, Alto Palomo Formation, basal breccias, co-ignimbrites, accretionary lapilli. RESUMEN: La Formación Alto Palomo está dividida en dos miembros: Palomo el inferior y Palmitos el supe- rior. Ambos están constituidos por tobas de lapilli pumíticos (flujos piroclásticos pumíticos). Tienen brechas ba- sales líticas o pumíticas (brechas co-ignimbríticas de rezago y de caída). En algunos sitios, en la base de estas secuencias, se observan niveles delgados de cenizas finas a medias (oleadas piroclásticas), dando una secuen- cia típica de flujos ignimbríticos.
    [Show full text]
  • Petrology and Geochemistry of Lavas
    CENTRAL AMERICA: GEOLOGY, RESOURCES AND HAZARDS; BUNDSCHUH & ALVARADO (EDS) 1 Chapter 22 Petrology and geochemistry of lavas MICHAEL J. CARR, LINA C. PATINO AND MARK D. FEIGENSON “This continuity disappears, however, if one considers individual parts of the [Central American] chain and examines separate groups of volcanoes within a restricted volcanic field. It then becomes apparent that the continuity of the province as a whole is the result of grouping excessively large segments of the chain.” A.R. McBirney: Compositional variations in Cenozoic calc- alkaline suites of Central America. Intern. Upper Mantle Sci. Rept. 16, 1969. 22.1 INTRODUCTION Since the elegant summary of Central American geology by Weyl [1] in 1980, petrological and geochemical studies unveiled large variations in the Tertiary and Quaternary volcanics both along the volcanic chain and across it. The active volcanoes define an abrupt volcanic front, located 165 to 190 km inland from the Middle America trench (MAT). The front consists of 39 distinct centers or clusters of vents that occur in 100 to 300 km long lineaments or segments. Most of the active volcanic centers are complexes constructed primarily of basaltic to andesitic lavas. Several centers include calderas that erupted extensive silicic fall and flow deposits. Throughout most of Central America, the active volcanoes lie on the trenchward side of an extensive plateau of Tertiary volcanics, comprising primarily voluminous ignimbrite sheets that dominate the Tertiary topography. Mafic composite volcanoes, the predecessors of the active volcanic front, are recognizable in many areas and should ultimately be useful for defining the past positions of the volcanic front.
    [Show full text]
  • 3D Density Modeling of the Central American Isthmus from Satellite
    3D Density Modeling of the Central American Isthmus from Satellite Derived Gravity Data Dissertation zur Erlangung des Doktorgrades "Dr. rer. nat." der Mathematisch-Naturwissenschaftlichen Fakultät der Christian-Albrechts-Universität zu Kiel vorgelegt von Oscar H. Lücke Institut für Geowissenschaften, Abteilung Geophysik Kiel, 2012 Erstgutachter: Prof. Dr. Hans-Jürgen Götze Zweitgutachter: Prof. Dr. Wolfgang Rabbel Tag der mündlichen Prüfung: 21. August, 2012. gez. Prof. Dr. Lutz Kipp, Dekan i Abstract The combined geopotential models based on satellite and surface gravity data provide a homogenous gravity database with near global coverage. In this work, the data from the EGM2008 Combined Geopotential Model has been interpreted to prepare a comprehensive three dimensional model of the lithospheric density structure along the Central American Isthmus. The main focus of the model is the interpretation of the subduction process along the Middle American Trench and the segmentation of the oceanic Cocos and Nazca plates and the overriding Caribbean Plate. The viability of the EGM2008 data as input for the forward modeling has been assessed in terms of resolution and consistency with surface gravity data. For this purpose, a detailed surface gravity database was compiled and homogenized for Costa Rica and then compared with a subset of different data products from EGM2008. The Bouguer anomaly calculated from the gravity disturbance (geophysical anomaly) was determined to be the most consistent with the anomalies obtained from the surface stations, particularly in areas of high topography. The analysis also determined the areas in which the lower wavelengths from EGM2008 were dependent on the existence of surface gravity stations and the areas in which fill-in data may have been used to achieve its maximum spatial resolution.
    [Show full text]
  • Exodus Walking & Trekking 2019.Pdf
    ICONIC TREKS World-renowned trails WALKING VIVA ESPAÑA A different side to Spain TROPICAL TRAILS & TREKKING Volcanoes, jungles & beaches 2019/2020 STEP INTO adventure I’ve loved trekking since doing my Gold Duke if you’d prefer to travel with a group of family of Edinburgh expedition as a teenager. Since or friends (p.7). then I’ve seen the sun rise from the top of This year I’m really excited about the Kilimanjaro, wondered at the magic of the Kumono Kodo Trail (p.10) in Japan. Starting Inca Trail and soaked in the atmosphere at in Kyoto and ending in Tokyo it shows off the Everest Base Camp. The Himalaya unfolding best of the countryside. before me was breathtaking, as was trekking All of our adventures are carefully crafted so to the 5643m summit of Kala Patthar with you’ll get the best out of each destination. And bluebird skies and the bright colours of the we give our best too, travelling responsibly, fluttering prayer flags. Travel with Exodus, working hard to eradicate the use of single-use and these magic moments can be yours too. bottles on our adventures and enriching the One of the things I love most about walking lives of our porters via the Porter Project (p20). is the opportunity to really get away from it Whether you’re a solo traveller looking to all. Being able to turn off your phone and get meet like-minded people on a once-in-a- to know the people around you. You’ll always lifetime group trip, a couple looking to do your be travelling with like-minded people, making own thing on a self-guided walk, or a group of our trips great for groups and solo travellers enthusiasts who want to tailormake your own alike.
    [Show full text]
  • Program, Abstracts, and Field Trip Roadlog for International Gold Conference, San Jose, Costa Rica, October 20-22, 1987
    Program, Abstracts, and Field Trip Roadlog for International Gold Conference, San Jose, Costa Rica, October 20-22, 1987 edited by Steve Ludington and William C. Bagby U.S. Geological Survey 345 Middlefield Road Menlo Park, CA 94025 and Stephen L. Bolivar Los Alamos National Laboratory Los Alamos, New Mexico 87545 Open-file Report 87-602 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature During 1986 and 1987, the U. S. Geological Survey, in cooperation with Los Alamos National Laboratories, conducted a resource assessment of Costa Rica. This work culminated in the production of 1-1865, Mineral Resource Assessment of the Republic of Costa Rica. In October of 1987, a meeting was held in San Jos6, Costa Rica, in order to present the results of the joint U. S. Geological Survey - Los Alamos work to the Central American geologic community and to the world mining industry. This report is the record of that meeting, and contains the program, abstracts, field- trip guide, and short biographical sketches of the speakers. International Gold Conference Conferencia International de Oro San Jose, Costa Rica October 20-22, 1987 Hotel Sheraton Herradura organizada por Ministerio de Recursos Naturales, Energia y Minas Minera National, S. fl. Los Rlamos National Laboratories United States Geological Suruey INTERNRTIONRL GOLD CONFERENCE CDNFERENCIB INTERNflCIONRL DEL PRO San Jose, Costa Rica 20-22 Octubre, 1987 Hotel Sheraton Herradura Martes 20 de Octubre 8:30 am Inauguration Inauguration Introduction Introduction: Sr. Jose" Maria Blanco, M. Sc., Gerente General, Minera Nacional, S.A.
    [Show full text]
  • Geothermal Development in Central America: Opportunities and Difficulties
    Presented at “Short Course on Surface Exploration for Geothermal Resources”, organized by UNU-GTP and LaGeo, in Ahuachapan and Santa Tecla, El Salvador, 17-30 October, 2009. GEOTHERMAL TRAINING PROGRAMME LaGeo S.A. de C.V. GEOTHERMAL DEVELOPMENT IN CENTRAL AMERICA: OPPORTUNITIES AND DIFFICULTIES Carlos Pullinger LaGeo S.A. de C.V. 15 Av. Sur, Col. Utila, Santa Tecla, EL SALVADOR [email protected] ABSTRACT Geothermal exploration in Central America began in the 1960’s and electricity generation from this resource, a decade later. Despite a potential capacity of 8 GW available with the present technology and 13 GW using enhanced technology, only a fraction has been developed. Three and a half decades after the initial production began in Ahuachapán, El Salvador; the total installed capacity from geothermal resources in Central America adds up to 530 MW, only about 5% of the total geothermal potential of the region. Clearly, several factors have contributed to the delay in the development of the geothermal resources in the region. Amongst these are political instability, regulatory, institutional, political, economic and financial barriers, which are common problems in the whole region. In order to revert this trend and accelerate the geothermal development in the future, the National Energy Authorities have to take clear actions to promote the development of known high enthalpy resources and invest in basic exploration of low-medium enthalpy resources, in order to fully take advantage of this indigenous source of energy that has several economic, social and environmental advantages over other renewable and non-renewable sources of energy. 1. INTRODUCTION Central America’s location along the tectonically active margin between the Cocos and Caribbean tectonic plates is the main reason for the existence of many high temperature geothermal areas.
    [Show full text]
  • Rain Generated Lahars Prior to the 2018 Catastrophic Eruption of Fuego Volcano, Guatemala
    Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2020 RAIN GENERATED LAHARS PRIOR TO THE 2018 CATASTROPHIC ERUPTION OF FUEGO VOLCANO, GUATEMALA Claudia Buondonno Michigan Technological University, [email protected] Copyright 2020 Claudia Buondonno Recommended Citation Buondonno, Claudia, "RAIN GENERATED LAHARS PRIOR TO THE 2018 CATASTROPHIC ERUPTION OF FUEGO VOLCANO, GUATEMALA", Open Access Master's Thesis, Michigan Technological University, 2020. https://doi.org/10.37099/mtu.dc.etdr/1150 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Environmental Indicators and Impact Assessment Commons, Geological Engineering Commons, Geology Commons, and the Volcanology Commons RAIN GENERATED LAHARS PRIOR TO THE 2018 CATASTROPHIC ERUPTION OF FUEGO VOLCANO, GUATEMALA By Claudia Buondonno A THESIS Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In Geology MICHIGAN TECHNOLOGICAL UNIVERSITY 2020 © 2020 Claudia Buondonno This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE in Geology. Department of Geological and Mining Engineering and Sciences Thesis Co-Advisor: Dr. Rudiger Escobar Wolf Thesis Co-Advisor: Dr. Paolo Frattini Committee Member: Dr. Thomas Oommen Committee Member: Dr. Simon Carn Department Chair: Dr. John Gierke Table of Contents 1. Introduction .........................................................................................................
    [Show full text]