Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua
Identifieur interne : 000283 ( Istex/Corpus ); précédent : 000282; suivant : 000284Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua
Auteurs : S. C. P. Pearson ; K. Kiyosugi ; H. L. Lehto ; J. A. Saballos ; C. B. Connor ; W. E. SanfordSource :
- Geochemistry, Geophysics, Geosystems [ 1525-2027 ] ; 2012-05.
English descriptors
- KwdEn :
- Active crater, Anomaly, Basalt, Basaltic, Caldera, Central america, Chiodini, Cinder, Comalito, Comalito cinder cone, Convection, Crater, Degassing, Degassing zone, Degassing zones, Diffuse, Diffuse degassing, Diffuse degassing zones, Distinct degassing zones, Earth planet, Enthalpy, Equal mixture, Fault core, Flank, Flank degassing, Fluid circulation, Fluid flow, Fluid flux, Fluid injection, Fluid injection rate, Fluid transport, Flux measurements, Footwall, Fracture, Fracture zone, Geochemistry, Geochemistry geophysics geosystems, Geol, Geophys, Geophysical, Geophysics, Geosystems, Geotherm, Good agreement, Groundwater, Groundwater convection, Heat injection, Heat injection rate, Heat output, High permeability, Hydrologic system, Hydrothermal, Hydrothermal models, Hydrothermal system, Hydrothermal systems, Impermeable, Impermeable faults, Injection, Injection rate, Lava, Lava ponding, Lett, Lewicki, Lower permeability, Macneil, Magmatic, Magnetic anomalies, Magnetic anomaly, Magnetic data, Magnetic measurements, Magnetic profiles, Magnetization, Masaya, Masaya caldera, Masaya cone, Masaya hydrothermal system, Masaya hydrothermal system figure, Masaya volcano, Maximum heat flux, Maximum temperature, Model results, Modeling, Nicaragua, Normal faults, Numerical modeling, Numerical models, Permeability, Permeability variations, Plume, Rock permeability, Rymer, Santiago, Santiago crater, Scoria, Study area, Surface temperatures, Topographic, Tough2, Tough2 model, Tough2 modeling, Vadose, Vadose zone, Volcanic, Volcanic activity, Volcano, Volcanol, Water table, Water table temperature, Water vapor, West fault, Zlotnicki, Zone.
- Teeft :
- Active crater, Anomaly, Basalt, Basaltic, Caldera, Central america, Chiodini, Cinder, Comalito, Comalito cinder cone, Convection, Crater, Degassing, Degassing zone, Degassing zones, Diffuse, Diffuse degassing, Diffuse degassing zones, Distinct degassing zones, Earth planet, Enthalpy, Equal mixture, Fault core, Flank, Flank degassing, Fluid circulation, Fluid flow, Fluid flux, Fluid injection, Fluid injection rate, Fluid transport, Flux measurements, Footwall, Fracture, Fracture zone, Geochemistry, Geochemistry geophysics geosystems, Geol, Geophys, Geophysical, Geophysics, Geosystems, Geotherm, Good agreement, Groundwater, Groundwater convection, Heat injection, Heat injection rate, Heat output, High permeability, Hydrologic system, Hydrothermal, Hydrothermal models, Hydrothermal system, Hydrothermal systems, Impermeable, Impermeable faults, Injection, Injection rate, Lava, Lava ponding, Lett, Lewicki, Lower permeability, Macneil, Magmatic, Magnetic anomalies, Magnetic anomaly, Magnetic data, Magnetic measurements, Magnetic profiles, Magnetization, Masaya, Masaya caldera, Masaya cone, Masaya hydrothermal system, Masaya hydrothermal system figure, Masaya volcano, Maximum heat flux, Maximum temperature, Model results, Modeling, Nicaragua, Normal faults, Numerical modeling, Numerical models, Permeability, Permeability variations, Plume, Rock permeability, Rymer, Santiago, Santiago crater, Scoria, Study area, Surface temperatures, Topographic, Tough2, Tough2 model, Tough2 modeling, Vadose, Vadose zone, Volcanic, Volcanic activity, Volcano, Volcanol, Water table, Water table temperature, Water vapor, West fault, Zlotnicki, Zone.
Abstract
We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (∼250 m), relatively impermeable normal faults dipping at ∼60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE‐SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO2 to the NW of the faults and an absence of CO2 to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3–4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 × 10−5 kg/m2s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.
Geophysics combined with modeling is a powerful tool to map shallow subsurface Groundwater convection on a volcano can explain diffuse degassing distribution Near‐surface structure is a major control on surface fluid flux and temperature
Url:
DOI: 10.1029/2012GC004117
Links to Exploration step
ISTEX:1F8E1BD58476F01BF189B56363F7D73624F13826Le document en format XML
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Pearson</name><affiliation><mods:affiliation>GNS Science, Wairakei Research Centre, 114 Karetoto Road, RD4, Taupo 3384, New Zealand</mods:affiliation></affiliation><affiliation><mods:affiliation>E-mail: s.pearson@gns.cri.nz</mods:affiliation></affiliation></author><author><name sortKey="Kiyosugi, K" sort="Kiyosugi, K" uniqKey="Kiyosugi K" first="K." last="Kiyosugi">K. Kiyosugi</name><affiliation><mods:affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</mods:affiliation></affiliation></author><author><name sortKey="Lehto, H L" sort="Lehto, H L" uniqKey="Lehto H" first="H. L." last="Lehto">H. L. Lehto</name><affiliation><mods:affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</mods:affiliation></affiliation></author><author><name sortKey="Saballos, J A" sort="Saballos, J A" uniqKey="Saballos J" first="J. A." last="Saballos">J. A. 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Sanford</name><affiliation><mods:affiliation>U.S. Geological Survey, Mail Stop 431, Reston, Virginia 20192, USA</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j" type="main">Geochemistry, Geophysics, Geosystems</title><title level="j" type="alt">GEOCHEMISTRY, GEOPHYSICS, GEOSYSTEMS</title><idno type="ISSN">1525-2027</idno><idno type="eISSN">1525-2027</idno><imprint><biblScope unit="vol">13</biblScope><biblScope unit="issue">5</biblScope><biblScope unit="page-count">21</biblScope><date type="published" when="2012-05">2012-05</date></imprint><idno type="ISSN">1525-2027</idno></series></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">1525-2027</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Active crater</term><term>Anomaly</term><term>Basalt</term><term>Basaltic</term><term>Caldera</term><term>Central america</term><term>Chiodini</term><term>Cinder</term><term>Comalito</term><term>Comalito cinder cone</term><term>Convection</term><term>Crater</term><term>Degassing</term><term>Degassing zone</term><term>Degassing zones</term><term>Diffuse</term><term>Diffuse degassing</term><term>Diffuse degassing zones</term><term>Distinct degassing zones</term><term>Earth planet</term><term>Enthalpy</term><term>Equal mixture</term><term>Fault core</term><term>Flank</term><term>Flank degassing</term><term>Fluid circulation</term><term>Fluid flow</term><term>Fluid flux</term><term>Fluid injection</term><term>Fluid injection rate</term><term>Fluid transport</term><term>Flux measurements</term><term>Footwall</term><term>Fracture</term><term>Fracture zone</term><term>Geochemistry</term><term>Geochemistry geophysics geosystems</term><term>Geol</term><term>Geophys</term><term>Geophysical</term><term>Geophysics</term><term>Geosystems</term><term>Geotherm</term><term>Good agreement</term><term>Groundwater</term><term>Groundwater convection</term><term>Heat injection</term><term>Heat injection rate</term><term>Heat output</term><term>High permeability</term><term>Hydrologic system</term><term>Hydrothermal</term><term>Hydrothermal models</term><term>Hydrothermal system</term><term>Hydrothermal systems</term><term>Impermeable</term><term>Impermeable faults</term><term>Injection</term><term>Injection rate</term><term>Lava</term><term>Lava ponding</term><term>Lett</term><term>Lewicki</term><term>Lower permeability</term><term>Macneil</term><term>Magmatic</term><term>Magnetic anomalies</term><term>Magnetic anomaly</term><term>Magnetic data</term><term>Magnetic measurements</term><term>Magnetic profiles</term><term>Magnetization</term><term>Masaya</term><term>Masaya caldera</term><term>Masaya cone</term><term>Masaya hydrothermal system</term><term>Masaya hydrothermal system figure</term><term>Masaya volcano</term><term>Maximum heat flux</term><term>Maximum temperature</term><term>Model results</term><term>Modeling</term><term>Nicaragua</term><term>Normal faults</term><term>Numerical modeling</term><term>Numerical models</term><term>Permeability</term><term>Permeability variations</term><term>Plume</term><term>Rock permeability</term><term>Rymer</term><term>Santiago</term><term>Santiago crater</term><term>Scoria</term><term>Study area</term><term>Surface temperatures</term><term>Topographic</term><term>Tough2</term><term>Tough2 model</term><term>Tough2 modeling</term><term>Vadose</term><term>Vadose zone</term><term>Volcanic</term><term>Volcanic activity</term><term>Volcano</term><term>Volcanol</term><term>Water table</term><term>Water table temperature</term><term>Water vapor</term><term>West fault</term><term>Zlotnicki</term><term>Zone</term></keywords><keywords scheme="Teeft" xml:lang="en"><term>Active crater</term><term>Anomaly</term><term>Basalt</term><term>Basaltic</term><term>Caldera</term><term>Central america</term><term>Chiodini</term><term>Cinder</term><term>Comalito</term><term>Comalito cinder cone</term><term>Convection</term><term>Crater</term><term>Degassing</term><term>Degassing zone</term><term>Degassing zones</term><term>Diffuse</term><term>Diffuse degassing</term><term>Diffuse degassing zones</term><term>Distinct degassing zones</term><term>Earth planet</term><term>Enthalpy</term><term>Equal mixture</term><term>Fault core</term><term>Flank</term><term>Flank degassing</term><term>Fluid circulation</term><term>Fluid flow</term><term>Fluid flux</term><term>Fluid injection</term><term>Fluid injection rate</term><term>Fluid transport</term><term>Flux measurements</term><term>Footwall</term><term>Fracture</term><term>Fracture zone</term><term>Geochemistry</term><term>Geochemistry geophysics geosystems</term><term>Geol</term><term>Geophys</term><term>Geophysical</term><term>Geophysics</term><term>Geosystems</term><term>Geotherm</term><term>Good agreement</term><term>Groundwater</term><term>Groundwater convection</term><term>Heat injection</term><term>Heat injection rate</term><term>Heat output</term><term>High permeability</term><term>Hydrologic system</term><term>Hydrothermal</term><term>Hydrothermal models</term><term>Hydrothermal system</term><term>Hydrothermal systems</term><term>Impermeable</term><term>Impermeable faults</term><term>Injection</term><term>Injection rate</term><term>Lava</term><term>Lava ponding</term><term>Lett</term><term>Lewicki</term><term>Lower permeability</term><term>Macneil</term><term>Magmatic</term><term>Magnetic anomalies</term><term>Magnetic anomaly</term><term>Magnetic data</term><term>Magnetic measurements</term><term>Magnetic profiles</term><term>Magnetization</term><term>Masaya</term><term>Masaya caldera</term><term>Masaya cone</term><term>Masaya hydrothermal system</term><term>Masaya hydrothermal system figure</term><term>Masaya volcano</term><term>Maximum heat flux</term><term>Maximum temperature</term><term>Model results</term><term>Modeling</term><term>Nicaragua</term><term>Normal faults</term><term>Numerical modeling</term><term>Numerical models</term><term>Permeability</term><term>Permeability variations</term><term>Plume</term><term>Rock permeability</term><term>Rymer</term><term>Santiago</term><term>Santiago crater</term><term>Scoria</term><term>Study area</term><term>Surface temperatures</term><term>Topographic</term><term>Tough2</term><term>Tough2 model</term><term>Tough2 modeling</term><term>Vadose</term><term>Vadose zone</term><term>Volcanic</term><term>Volcanic activity</term><term>Volcano</term><term>Volcanol</term><term>Water table</term><term>Water table temperature</term><term>Water vapor</term><term>West fault</term><term>Zlotnicki</term><term>Zone</term></keywords></textClass></profileDesc></teiHeader><front><div type="abstract">We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (∼250 m), relatively impermeable normal faults dipping at ∼60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE‐SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO2 to the NW of the faults and an absence of CO2 to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3–4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 × 10−5 kg/m2s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.</div><div type="abstract">Geophysics combined with modeling is a powerful tool to map shallow subsurface Groundwater convection on a volcano can explain diffuse degassing distribution Near‐surface structure is a major control on surface fluid flux and temperature</div></front></TEI><istex><corpusName>wiley</corpusName><keywords><teeft><json:string>masaya</json:string><json:string>permeability</json:string><json:string>degassing</json:string><json:string>hydrothermal</json:string><json:string>masaya volcano</json:string><json:string>groundwater</json:string><json:string>volcanol</json:string><json:string>caldera</json:string><json:string>geophysics</json:string><json:string>geosystems</json:string><json:string>geochemistry geophysics geosystems</json:string><json:string>fracture</json:string><json:string>chiodini</json:string><json:string>geophys</json:string><json:string>geotherm</json:string><json:string>anomaly</json:string><json:string>volcano</json:string><json:string>fracture zone</json:string><json:string>tough2</json:string><json:string>comalito</json:string><json:string>injection rate</json:string><json:string>diffuse degassing</json:string><json:string>geophysical</json:string><json:string>vadose</json:string><json:string>lewicki</json:string><json:string>fluid flow</json:string><json:string>basaltic</json:string><json:string>groundwater convection</json:string><json:string>magnetization</json:string><json:string>geol</json:string><json:string>lett</json:string><json:string>macneil</json:string><json:string>modeling</json:string><json:string>santiago</json:string><json:string>comalito cinder cone</json:string><json:string>zlotnicki</json:string><json:string>vadose zone</json:string><json:string>basalt</json:string><json:string>impermeable</json:string><json:string>footwall</json:string><json:string>masaya caldera</json:string><json:string>masaya hydrothermal system</json:string><json:string>lava</json:string><json:string>fluid flux</json:string><json:string>rymer</json:string><json:string>masaya hydrothermal system figure</json:string><json:string>magmatic</json:string><json:string>flux measurements</json:string><json:string>scoria</json:string><json:string>nicaragua</json:string><json:string>topographic</json:string><json:string>masaya cone</json:string><json:string>santiago crater</json:string><json:string>water table</json:string><json:string>magnetic data</json:string><json:string>degassing zones</json:string><json:string>crater</json:string><json:string>flank</json:string><json:string>geochemistry</json:string><json:string>fluid injection rate</json:string><json:string>surface temperatures</json:string><json:string>active crater</json:string><json:string>distinct degassing zones</json:string><json:string>volcanic activity</json:string><json:string>water vapor</json:string><json:string>heat injection rate</json:string><json:string>maximum temperature</json:string><json:string>tough2 model</json:string><json:string>good agreement</json:string><json:string>volcanic</json:string><json:string>convection</json:string><json:string>plume</json:string><json:string>heat injection</json:string><json:string>flank degassing</json:string><json:string>fluid circulation</json:string><json:string>degassing zone</json:string><json:string>magnetic measurements</json:string><json:string>study area</json:string><json:string>magnetic anomaly</json:string><json:string>permeability variations</json:string><json:string>normal faults</json:string><json:string>numerical modeling</json:string><json:string>diffuse degassing zones</json:string><json:string>numerical models</json:string><json:string>model results</json:string><json:string>zone</json:string><json:string>injection</json:string><json:string>tough2 modeling</json:string><json:string>west fault</json:string><json:string>hydrothermal system</json:string><json:string>hydrothermal models</json:string><json:string>rock permeability</json:string><json:string>hydrothermal systems</json:string><json:string>equal mixture</json:string><json:string>lava ponding</json:string><json:string>fluid transport</json:string><json:string>high permeability</json:string><json:string>impermeable faults</json:string><json:string>fluid injection</json:string><json:string>lower permeability</json:string><json:string>water table temperature</json:string><json:string>central america</json:string><json:string>magnetic anomalies</json:string><json:string>magnetic profiles</json:string><json:string>maximum heat flux</json:string><json:string>fault core</json:string><json:string>heat output</json:string><json:string>hydrologic system</json:string><json:string>earth planet</json:string><json:string>cinder</json:string><json:string>diffuse</json:string><json:string>enthalpy</json:string></teeft></keywords><author><json:item><name>S. C. P. Pearson</name><affiliations><json:string>GNS Science, Wairakei Research Centre, 114 Karetoto Road, RD4, Taupo 3384, New Zealand</json:string><json:string>E-mail: s.pearson@gns.cri.nz</json:string></affiliations></json:item><json:item><name>K. Kiyosugi</name><affiliations><json:string>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</json:string></affiliations></json:item><json:item><name>H. L. Lehto</name><affiliations><json:string>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</json:string></affiliations></json:item><json:item><name>J. A. Saballos</name><affiliations><json:string>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</json:string></affiliations></json:item><json:item><name>C. B. Connor</name><affiliations><json:string>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</json:string></affiliations></json:item><json:item><name>W. E. Sanford</name><affiliations><json:string>U.S. Geological Survey, Mail Stop 431, Reston, Virginia 20192, USA</json:string></affiliations></json:item></author><subject><json:item><lang><json:string>eng</json:string></lang><value>CO2 flux</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>TOUGH2 modeling</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>magnetics</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>self‐potential</value></json:item></subject><articleId><json:string>2012GC004117</json:string></articleId><language><json:string>eng</json:string></language><originalGenre><json:string>article</json:string></originalGenre><qualityIndicators><score>9.44</score><pdfVersion>1.6</pdfVersion><pdfPageSize>612 x 792 pts (letter)</pdfPageSize><refBibsNative>true</refBibsNative><abstractCharCount>1558</abstractCharCount><pdfWordCount>9968</pdfWordCount><pdfCharCount>61573</pdfCharCount><pdfPageCount>21</pdfPageCount><abstractWordCount>245</abstractWordCount></qualityIndicators><title>Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title><genre><json:string>article</json:string></genre><host><title>Geochemistry, Geophysics, Geosystems</title><language><json:string>unknown</json:string></language><doi><json:string>10.1002/(ISSN)1525-2027</json:string></doi><issn><json:string>1525-2027</json:string></issn><eissn><json:string>1525-2027</json:string></eissn><publisherId><json:string>GGGE</json:string></publisherId><volume>13</volume><issue>5</issue><pages><first>n/a</first><last>n/a</last><total>21</total></pages><genre><json:string>journal</json:string></genre><subject><json:item><value>BIOGEOSCIENCES</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>GEOCHEMISTRY</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>MARINE GEOLOGY AND GEOPHYSICS</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>MINERALOGY AND PETROLOGY</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>PHYSICAL PROPERTIES OF ROCKS</value></json:item><json:item><value>Fracture and flow</value></json:item><json:item><value>TECTONOPHYSICS</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>VOLCANOLOGY</value></json:item><json:item><value>Hydrothermal systems</value></json:item><json:item><value>Volcanic gases</value></json:item></subject></host><categories><wos><json:string>science</json:string><json:string>geochemistry & geophysics</json:string></wos><scienceMetrix></scienceMetrix></categories><publicationDate>2012</publicationDate><copyrightDate>2012</copyrightDate><doi><json:string>10.1029/2012GC004117</json:string></doi><id>1F8E1BD58476F01BF189B56363F7D73624F13826</id><score>1</score><fulltext><json:item><extension>pdf</extension><original>true</original><mimetype>application/pdf</mimetype><uri>https://api.istex.fr/document/1F8E1BD58476F01BF189B56363F7D73624F13826/fulltext/pdf</uri></json:item><json:item><extension>zip</extension><original>false</original><mimetype>application/zip</mimetype><uri>https://api.istex.fr/document/1F8E1BD58476F01BF189B56363F7D73624F13826/fulltext/zip</uri></json:item><istex:fulltextTEI uri="https://api.istex.fr/document/1F8E1BD58476F01BF189B56363F7D73624F13826/fulltext/tei"><teiHeader><fileDesc><titleStmt><title level="a" type="main">Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title></titleStmt><publicationStmt><publisher>Blackwell Publishing Ltd</publisher><availability><licence>Copyright 2012 by the American Geophysical Union</licence></availability><date type="published" when="2012-05"></date></publicationStmt><notesStmt><note type="content-type" subtype="article" source="article" scheme="https://content-type.data.istex.fr/ark:/67375/XTP-6N5SZHKN-D">article</note><note type="publication-type" subtype="journal" scheme="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</note></notesStmt><sourceDesc><biblStruct type="article"><analytic><title level="a" type="main">Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title><title level="a" type="short">MASAYA HYDROTHERMAL SYSTEM</title><author xml:id="author-0000"><persName><forename type="first">S. C. P.</forename><surname>Pearson</surname></persName><email>s.pearson@gns.cri.nz</email><affiliation>GNS Science, Wairakei Research Centre, 114 Karetoto Road, RD4, Taupo 3384, New Zealand<address><country key="NZ"></country></address></affiliation></author><author xml:id="author-0001"><persName><forename type="first">K.</forename><surname>Kiyosugi</surname></persName><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA<address><country key="US"></country></address></affiliation></author><author xml:id="author-0002"><persName><forename type="first">H. L.</forename><surname>Lehto</surname></persName><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA<address><country key="US"></country></address></affiliation></author><author xml:id="author-0003"><persName><forename type="first">J. A.</forename><surname>Saballos</surname></persName><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA<address><country key="US"></country></address></affiliation></author><author xml:id="author-0004"><persName><forename type="first">C. B.</forename><surname>Connor</surname></persName><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA<address><country key="US"></country></address></affiliation></author><author xml:id="author-0005"><persName><forename type="first">W. E.</forename><surname>Sanford</surname></persName><affiliation>U.S. Geological Survey, Mail Stop 431, Reston, Virginia 20192, USA<address><country key="US"></country></address></affiliation></author><idno type="istex">1F8E1BD58476F01BF189B56363F7D73624F13826</idno><idno type="DOI">10.1029/2012GC004117</idno><idno type="editorialOffice">2012GC004117</idno><idno type="society">Q05011</idno><idno type="unit">GGGE2227</idno><idno type="toTypesetVersion">file:GGGE.GGGE2227.pdf</idno></analytic><monogr><title level="j" type="main">Geochemistry, Geophysics, Geosystems</title><title level="j" type="alt">GEOCHEMISTRY, GEOPHYSICS, GEOSYSTEMS</title><idno type="pISSN">1525-2027</idno><idno type="eISSN">1525-2027</idno><idno type="book-DOI">10.1002/(ISSN)1525-2027</idno><idno type="book-part-DOI">10.1002/jgra.v13.5</idno><idno type="product">GGGE</idno><idno type="coden">GGGGFR</idno><imprint><biblScope unit="vol">13</biblScope><biblScope unit="issue">5</biblScope><biblScope unit="page-count">21</biblScope><date type="published" when="2012-05"></date></imprint></monogr></biblStruct></sourceDesc></fileDesc><profileDesc><abstract style="main"><p xml:id="ggge2227-para-0004">We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (∼250 m), relatively impermeable normal faults dipping at ∼60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE‐SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO<hi rend="subscript">2</hi> to the NW of the faults and an absence of CO<hi rend="subscript">2</hi> to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3–4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 × 10<hi rend="superscript">−5</hi> kg/m<hi rend="superscript">2</hi>s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.</p></abstract><abstract style="short"><head>Key Points</head><p xml:id="ggge2227-para-0005"><list style="bulleted"><item>Geophysics combined with modeling is a powerful tool to map shallow subsurface</item><item>Groundwater convection on a volcano can explain diffuse degassing distribution</item><item>Near‐surface structure is a major control on surface fluid flux and temperature</item></list></p></abstract><textClass><keywords><term xml:id="ggge2227-kwd-0001">CO<hi rend="subscript">2</hi> flux</term><term xml:id="ggge2227-kwd-0002">TOUGH2 modeling</term><term xml:id="ggge2227-kwd-0003">magnetics</term><term xml:id="ggge2227-kwd-0004">self‐potential</term></keywords><classCode scheme="http://psi.agu.org/taxonomy5/0400">BIOGEOSCIENCES</classCode><classCode scheme="http://psi.agu.org/taxonomy5/1000">GEOCHEMISTRY</classCode><classCode scheme="http://psi.agu.org/taxonomy5/3000">MARINE GEOLOGY AND GEOPHYSICS</classCode><classCode scheme="http://psi.agu.org/taxonomy5/3600">MINERALOGY AND PETROLOGY</classCode><classCode scheme="http://psi.agu.org/taxonomy5/4800">OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL</classCode><classCode scheme="http://psi.agu.org/taxonomy5/5100">PHYSICAL PROPERTIES OF ROCKS</classCode><classCode scheme="http://psi.agu.org/taxonomy5/8100">TECTONOPHYSICS</classCode><classCode scheme="http://psi.agu.org/taxonomy5/8400">VOLCANOLOGY</classCode></textClass><langUsage><language ident="EN"></language></langUsage></profileDesc></teiHeader></istex:fulltextTEI><json:item><extension>txt</extension><original>false</original><mimetype>text/plain</mimetype><uri>https://api.istex.fr/document/1F8E1BD58476F01BF189B56363F7D73624F13826/fulltext/txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="Wiley, elements deleted: body"><istex:xmlDeclaration>version="1.0" encoding="UTF-8" standalone="yes"</istex:xmlDeclaration><istex:document><component type="serialArticle" version="2.0" xml:lang="en" xml:id="ggge2227"><header><publicationMeta level="product"><doi>10.1002/(ISSN)1525-2027</doi><issn type="print">1525-2027</issn><issn type="electronic">1525-2027</issn><idGroup><id type="product" value="GGGE"></id><id type="coden" value="GGGGFR"></id></idGroup><titleGroup><title type="main" xml:lang="en" sort="GEOCHEMISTRY, GEOPHYSICS, GEOSYSTEMS">Geochemistry, Geophysics, Geosystems</title><title type="short">Geochem. 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C. P.</givenNames></author>, <author><givenNames>K.</givenNames> <familyName>Kiyosugi</familyName></author>, <author><givenNames>H. L.</givenNames> <familyName>Lehto</familyName></author>, <author><givenNames>J. A.</givenNames> <familyName>Saballos</familyName></author>, <author><givenNames>C. B.</givenNames> <familyName>Connor</familyName></author>, and <author><givenNames>W. E.</givenNames> <familyName>Sanford</familyName></author> (<pubYear year="2012">2012</pubYear>), <articleTitle>Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</articleTitle>, <journalTitle>Geochem. Geophys. Geosyst.</journalTitle>, <vol>13</vol>, Q05011, doi:<accessionId ref="info:doi/10.1029/2012GC004117">10.1029/2012GC004117</accessionId>.</citation></selfCitationGroup><linkGroup><link type="toTypesetVersion" href="file:GGGE.GGGE2227.pdf"></link></linkGroup></publicationMeta><contentMeta><countGroup><count type="wordTotal" number="11100"></count><count type="figureTotal" number="14"></count><count type="tableTotal" number="2"></count></countGroup><titleGroup><title type="main">Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title><title type="shortAuthors">PEARSON ET AL.</title><title type="short">MASAYA HYDROTHERMAL SYSTEM</title></titleGroup><creators><creator xml:id="ggge2227-cr-0001" creatorRole="author" affiliationRef="#ggge2227-aff-0001"><personName><givenNames>S. C. P.</givenNames><familyName>Pearson</familyName></personName><contactDetails><email>s.pearson@gns.cri.nz</email></contactDetails></creator><creator xml:id="ggge2227-cr-0002" creatorRole="author" affiliationRef="#ggge2227-aff-0002"><personName><givenNames>K.</givenNames><familyName>Kiyosugi</familyName></personName></creator><creator xml:id="ggge2227-cr-0003" creatorRole="author" affiliationRef="#ggge2227-aff-0002"><personName><givenNames>H. L.</givenNames><familyName>Lehto</familyName></personName></creator><creator xml:id="ggge2227-cr-0004" creatorRole="author" affiliationRef="#ggge2227-aff-0002"><personName><givenNames>J. A.</givenNames><familyName>Saballos</familyName></personName></creator><creator xml:id="ggge2227-cr-0005" creatorRole="author" affiliationRef="#ggge2227-aff-0002"><personName><givenNames>C. B.</givenNames><familyName>Connor</familyName></personName></creator><creator xml:id="ggge2227-cr-0006" creatorRole="author" affiliationRef="#ggge2227-aff-0003"><personName><givenNames>W. E.</givenNames><familyName>Sanford</familyName></personName></creator></creators><affiliationGroup><affiliation xml:id="ggge2227-aff-0001" countryCode="NZ" type="organization"><unparsedAffiliation>GNS Science, Wairakei Research Centre, 114 Karetoto Road, RD4, Taupo 3384, New Zealand</unparsedAffiliation></affiliation><affiliation xml:id="ggge2227-aff-0002" countryCode="US" type="organization"><unparsedAffiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</unparsedAffiliation></affiliation><affiliation xml:id="ggge2227-aff-0003" countryCode="US" type="organization"><unparsedAffiliation>U.S. Geological Survey, Mail Stop 431, Reston, Virginia 20192, USA</unparsedAffiliation></affiliation></affiliationGroup><keywordGroup type="author"><keyword xml:id="ggge2227-kwd-0001">CO<sub>2</sub> flux</keyword><keyword xml:id="ggge2227-kwd-0002">TOUGH2 modeling</keyword><keyword xml:id="ggge2227-kwd-0003">magnetics</keyword><keyword xml:id="ggge2227-kwd-0004">self‐potential</keyword></keywordGroup><supportingInformation xml:id="ggge2227-sup-0000"><p xml:id="ggge2227-para-0001">Auxiliary material for this article contains modeling results for TOUGH2 heat and fluid flow models of the hydrothermal system at Masaya volcano, Nicaragua.</p><p xml:id="ggge2227-para-0002">Auxiliary material files may require downloading to a local drive depending on platform, browser, configuration, and size. To open auxiliary materials in a browser, click on the label. To download, Right‐click and select “Save Target As…” (PC) or CTRL‐click and select “Download Link to Disk” (Mac).</p><p xml:id="ggge2227-para-0003">Additional file information is provided in the readme.txt.</p><supportingInfoItem><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0001-readme"></mediaResource><caption>readme.txt</caption></supportingInfoItem><supportingInfoItem xml:id="ggge2227-sup-0001"><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0002-ts01"></mediaResource><caption>Table S1. Model results for injecting 50% air, 50% water into the vadose zone.</caption></supportingInfoItem><supportingInfoItem xml:id="ggge2227-sup-0002"><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0003-ts02"></mediaResource><caption>Table S2. Model results for injecting single‐component air or water into the vadose zone.</caption></supportingInfoItem><supportingInfoItem xml:id="ggge2227-sup-0003"><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0004-ts03"></mediaResource><caption>Table S3. Model results for injecting fluid or heat into the base of the saturated zone model.</caption></supportingInfoItem><supportingInfoItem><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0005-t01"></mediaResource><caption>Tab‐delimited Table 1.</caption></supportingInfoItem><supportingInfoItem><mediaResource alt="supplementary data" mimeType="text/plain" href="urn-x:wiley:15252027:media:ggge2227:ggge2227-sup-0006-t02"></mediaResource><caption>Tab‐delimited Table 2.</caption></supportingInfoItem></supportingInformation><abstractGroup><abstract type="main"><p xml:id="ggge2227-para-0004" label="1">We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (∼250 m), relatively impermeable normal faults dipping at ∼60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE‐SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO<sub>2</sub> to the NW of the faults and an absence of CO<sub>2</sub> to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3–4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 × 10<sup>−5</sup> kg/m<sup>2</sup>s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.</p></abstract><abstract type="short"><title type="main">Key Points</title><p xml:id="ggge2227-para-0005"><list style="bulleted"><listItem>Geophysics combined with modeling is a powerful tool to map shallow subsurface</listItem><listItem>Groundwater convection on a volcano can explain diffuse degassing distribution</listItem><listItem>Near‐surface structure is a major control on surface fluid flux and temperature</listItem></list></p></abstract></abstractGroup></contentMeta></header></component></istex:document></istex:metadataXml><mods version="3.6"><titleInfo lang="en"><title>Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title></titleInfo><titleInfo type="abbreviated" lang="en"><title>MASAYA HYDROTHERMAL SYSTEM</title></titleInfo><titleInfo type="alternative" contentType="CDATA" lang="en"><title>Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua</title></titleInfo><name type="personal"><namePart type="given">S. C. P.</namePart><namePart type="family">Pearson</namePart><affiliation>GNS Science, Wairakei Research Centre, 114 Karetoto Road, RD4, Taupo 3384, New Zealand</affiliation><affiliation>E-mail: s.pearson@gns.cri.nz</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">K.</namePart><namePart type="family">Kiyosugi</namePart><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">H. L.</namePart><namePart type="family">Lehto</namePart><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">J. A.</namePart><namePart type="family">Saballos</namePart><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">C. B.</namePart><namePart type="family">Connor</namePart><affiliation>Department of Geology, University of South Florida, 4202 E. Fowler Avenue, SCA 528, Tampa, Florida 33620, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">W. E.</namePart><namePart type="family">Sanford</namePart><affiliation>U.S. Geological Survey, Mail Stop 431, Reston, Virginia 20192, USA</affiliation><role><roleTerm type="text">author</roleTerm></role></name><typeOfResource>text</typeOfResource><genre type="article" displayLabel="article"></genre><originInfo><publisher>Blackwell Publishing Ltd</publisher><dateIssued encoding="w3cdtf">2012-05</dateIssued><dateCaptured encoding="w3cdtf">2012-02-24</dateCaptured><dateValid encoding="w3cdtf">2012-04-16</dateValid><edition>Pearson, S. C. P., K. Kiyosugi, H. L. Lehto, J. A. Saballos, C. B. Connor, and W. E. Sanford (2012), Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya volcano, Nicaragua, Geochem. Geophys. Geosyst., 13, Q05011, doi:10.1029/2012GC004117.</edition><copyrightDate encoding="w3cdtf">2012</copyrightDate></originInfo><language><languageTerm type="code" authority="rfc3066">en</languageTerm><languageTerm type="code" authority="iso639-2b">eng</languageTerm></language><physicalDescription><internetMediaType>text/html</internetMediaType><extent unit="figures">14</extent><extent unit="tables">2</extent><extent unit="words">11100</extent></physicalDescription><abstract>We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (∼250 m), relatively impermeable normal faults dipping at ∼60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE‐SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO2 to the NW of the faults and an absence of CO2 to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3–4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 × 10−5 kg/m2s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.</abstract><abstract type="short">Geophysics combined with modeling is a powerful tool to map shallow subsurface Groundwater convection on a volcano can explain diffuse degassing distribution Near‐surface structure is a major control on surface fluid flux and temperature</abstract><subject><genre>keywords</genre><topic>CO2 flux</topic><topic>TOUGH2 modeling</topic><topic>magnetics</topic><topic>self‐potential</topic></subject><relatedItem type="host"><titleInfo><title>Geochemistry, Geophysics, Geosystems</title></titleInfo><titleInfo type="abbreviated"><title>Geochem. Geophys. Geosyst.</title></titleInfo><genre type="journal">journal</genre><note type="content"> Auxiliary material for this article contains modeling results for TOUGH2 heat and fluid flow models of the hydrothermal system at Masaya volcano, Nicaragua. Auxiliary material files may require downloading to a local drive depending on platform, browser, configuration, and size. To open auxiliary materials in a browser, click on the label. To download, Right‐click and select “Save Target As…” (PC) or CTRL‐click and select “Download Link to Disk” (Mac). Additional file information is provided in the readme.txt. Auxiliary material for this article contains modeling results for TOUGH2 heat and fluid flow models of the hydrothermal system at Masaya volcano, Nicaragua. Auxiliary material files may require downloading to a local drive depending on platform, browser, configuration, and size. To open auxiliary materials in a browser, click on the label. To download, Right‐click and select “Save Target As…” (PC) or CTRL‐click and select “Download Link to Disk” (Mac). Additional file information is provided in the readme.txt. Auxiliary material for this article contains modeling results for TOUGH2 heat and fluid flow models of the hydrothermal system at Masaya volcano, Nicaragua. Auxiliary material files may require downloading to a local drive depending on platform, browser, configuration, and size. To open auxiliary materials in a browser, click on the label. To download, Right‐click and select “Save Target As…” (PC) or CTRL‐click and select “Download Link to Disk” (Mac). Additional file information is provided in the readme.txt.Supporting Info Item: readme.txt - Table S1. Model results for injecting 50% air, 50% water into the vadose zone. - Table S2. Model results for injecting single‐component air or water into the vadose zone. - Table S3. Model results for injecting fluid or heat into the base of the saturated zone model. - Tab‐delimited Table 1. - Tab‐delimited Table 2. - </note><subject><genre>index-terms</genre><topic authorityURI="http://psi.agu.org/taxonomy5/0400">BIOGEOSCIENCES</topic><topic authorityURI="http://psi.agu.org/taxonomy5/0450">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/1000">GEOCHEMISTRY</topic><topic authorityURI="http://psi.agu.org/taxonomy5/1034">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/3000">MARINE GEOLOGY AND GEOPHYSICS</topic><topic authorityURI="http://psi.agu.org/taxonomy5/3017">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/3600">MINERALOGY AND PETROLOGY</topic><topic authorityURI="http://psi.agu.org/taxonomy5/3616">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/4800">OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL</topic><topic authorityURI="http://psi.agu.org/taxonomy5/4832">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/5100">PHYSICAL PROPERTIES OF ROCKS</topic><topic authorityURI="http://psi.agu.org/taxonomy5/5104">Fracture and flow</topic><topic authorityURI="http://psi.agu.org/taxonomy5/8100">TECTONOPHYSICS</topic><topic authorityURI="http://psi.agu.org/taxonomy5/8135">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/8400">VOLCANOLOGY</topic><topic authorityURI="http://psi.agu.org/taxonomy5/8424">Hydrothermal systems</topic><topic authorityURI="http://psi.agu.org/taxonomy5/8430">Volcanic gases</topic></subject><identifier type="ISSN">1525-2027</identifier><identifier type="eISSN">1525-2027</identifier><identifier type="DOI">10.1002/(ISSN)1525-2027</identifier><identifier type="CODEN">GGGGFR</identifier><identifier type="PublisherID">GGGE</identifier><part><date>2012</date><detail type="volume"><caption>vol.</caption><number>13</number></detail><detail type="issue"><caption>no.</caption><number>5</number></detail><extent unit="pages"><start>n/a</start><end>n/a</end><total>21</total></extent></part></relatedItem><identifier type="istex">1F8E1BD58476F01BF189B56363F7D73624F13826</identifier><identifier type="DOI">10.1029/2012GC004117</identifier><identifier type="ArticleID">2012GC004117</identifier><accessCondition type="use and reproduction" contentType="copyright">Copyright 2012 by the American Geophysical Union</accessCondition><recordInfo><recordContentSource>WILEY</recordContentSource></recordInfo></mods><json:item><extension>json</extension><original>false</original><mimetype>application/json</mimetype><uri>https://api.istex.fr/document/1F8E1BD58476F01BF189B56363F7D73624F13826/metadata/json</uri></json:item></metadata><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
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