Item talk:Q265231

{

 "USGS Publications Warehouse": {
   "@context": "https://schema.org",
   "@type": "Article",
   "additionalType": "Journal Article",
   "name": "Source mechanism of Vulcanian degassing at Popocat\u00e9petl Volcano, Mexico, determined from waveform inversions of very long period signals",
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       "value": "70029612",
       "url": "https://pubs.usgs.gov/publication/70029612"
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       "value": 70029612
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       "propertyID": "DOI",
       "value": "10.1029/2004JB003524",
       "url": "https://doi.org/10.1029/2004JB003524"
     },
     {
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       "propertyID": "ISSN",
       "value": "01480227"
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   ],
   "journal": {
     "@type": "Periodical",
     "name": "Journal of Geophysical Research B: Solid Earth",
     "volumeNumber": "110",
     "issueNumber": "7"
   },
   "inLanguage": "en",
   "isPartOf": [
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       "name": "Journal of Geophysical Research B: Solid Earth"
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   "datePublished": "2005",
   "dateModified": "2019-05-01",
   "abstract": "The source mechanism of very long period (VLP) signals accompanying volcanic degassing bursts at Popocat\u00e9petl is analyzed in the 15\u201370 s band by minimizing the residual error between data and synthetics calculated for a point source embedded in a homogeneous medium. The waveforms of two eruptions (23 April and 23 May 2000) representative of mild Vulcanian activity are well reproduced by our inversion, which takes into account volcano topography. The source centroid is positioned 1500 m below the western perimeter of the summit crater, and the modeled source is composed of a shallow dipping crack (sill with easterly dip of 10\u00b0) intersecting a steeply dipping crack (northeast striking dike dipping 83\u00b0 northwest), whose surface extension bisects the vent. Both cracks undergo a similar sequence of inflation, deflation, and reinflation, reflecting a cycle of pressurization, depressurization, and repressurization within a time interval of 3\u20135 min. The largest moment release occurs in the sill, showing a maximum volume change of 500\u20131000 m3, pressure drop of 3\u20135 MPa, and amplitude of recovered pressure equal to 1.2 times the amplitude of the pressure drop. In contrast, the maximum volume change in the dike is less (200\u2013300 m3), with a corresponding pressure drop of 1\u20132 MPa and pressure recovery equal to the pressure drop. Accompanying these volumetric sources are single-force components with magnitudes of 108\u00a0N, consistent with melt advection in response to pressure transients. The source time histories of the volumetric components of the source indicate that significant mass movement starts within the sill and triggers a mass movement response in the dike within a few seconds. Such source behavior is consistent with the opening of a pathway for escape of pent-up gases from slow pressurization of the sill driven by magma crystallization. The opening of this pathway and associated rapid evacuation of volcanic gases induces the pressure drop. Pressure recovery in the magma filling the sill is driven by diffusion of gases from the resulting supersaturated melt into bubbles. Assuming a penny-shaped crack at ambient pressure of 40 MPa, the observed pressure and volume variations can be modeled with the following attributes: crack radius (100 m), crack aperture (5 m), bubble number density (1010\u20131012\u00a0m\u22123), initial bubble radius (10\u22126\u00a0m), final bubble radius (\u223c10\u22125\u00a0m), and net decrease of gas concentration in the melt (0.01 wt %).",
   "description": "20 p.",
   "publisher": {
     "@type": "Organization",
     "name": "AGU Publications"
   },
   "author": [
     {
       "@type": "Person",
       "name": "Dawson, Phillip B. dawson@usgs.gov",
       "givenName": "Phillip B.",
       "familyName": "Dawson",
       "email": "dawson@usgs.gov",
       "affiliation": [
         {
           "@type": "Organization",
           "name": "Volcano Science Center",
           "url": "https://www.usgs.gov/centers/volcano-science-center"
         }
       ]
     },
     {
       "@type": "Person",
       "name": "Chouet, Bernard A. chouet@usgs.gov",
       "givenName": "Bernard A.",
       "familyName": "Chouet",
       "email": "chouet@usgs.gov",
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         "value": "0000-0001-5527-0532",
         "url": "https://orcid.org/0000-0001-5527-0532"
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         {
           "@type": "Organization",
           "name": "Volcano Science Center",
           "url": "https://www.usgs.gov/centers/volcano-science-center"
         }
       ]
     },
     {
       "@type": "Person",
       "name": "Arciniega-Ceballos, Alejandra",
       "givenName": "Alejandra",
       "familyName": "Arciniega-Ceballos"
     }
   ],
   "funder": [
     {
       "@type": "Organization",
       "name": "Volcano Hazards Program",
       "url": "https://www.usgs.gov/programs/VHP"
     }
   ],
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       "@type": "Place",
       "additionalType": "country",
       "name": "Mexico",
       "url": "https://geonames.org/4300612"
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       "@type": "Place",
       "additionalType": "unknown",
       "name": "Popocat\u00e9petl Volcano"
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