First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam
In this study, air, water, and host rock in show caves in a Vietnam’s karst region was monitored and analyzed to identify the ventilation regime and track the cave air CO2 sources. In general, the studied caves are well ventilated. In dynamic – multiple entrance caves, air ventilation is described w...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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University of South Florida Libraries
2018-01-01
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| Series: | International Journal of Speleology |
| Subjects: | |
| Online Access: | http://scholarcommons.usf.edu/ijs/vol47/iss1/8/ |
| _version_ | 1819023544859754496 |
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| author | Duc A. Trinh Quan H. Trinh Angel Fernández-Cortés David Mattey Javier G. Guinea |
| author_facet | Duc A. Trinh Quan H. Trinh Angel Fernández-Cortés David Mattey Javier G. Guinea |
| author_sort | Duc A. Trinh |
| collection | DOAJ |
| description | In this study, air, water, and host rock in show caves in a Vietnam’s karst region was monitored and analyzed to identify the ventilation regime and track the cave air CO2 sources. In general, the studied caves are well ventilated. In dynamic – multiple entrance caves, air ventilation is described with the use of U shape model. In static – single entrance cave, air circulation is explained by cold air trap model. Both ventilation models suggest that air is more circulated in winter than in summer. Seasonally, the cave air CO2 increases from early spring to summer. Value in the deepest part of the single-entrance cave is approximately 1,000 ppmv and 8,000 ppmv in early spring and summer, respectively. In multiple-entrance and wet caves, CO2 level is fairly constant all over the show section, increasing from 500 ppmv in early spring to 2,000 ppmv in summer. Data of microclimate, CO2 content, and particularly δ13C show that cave air, particularly in single entrance cave, has higher CO2 concentration during summer due to a stagnation of cave air circulation and an elevated CO2 input from soil and epikarst. The cave air CO2 increase is also observed after intense rainfalls. A factor that increase cave air CO2 in show caves during the festive days could probably be huma n exhaling but the extent of human factor in these studied cave systems should be further investigated. Cave waters including cave pools and streams mediate CO2 level in wet caves. Above all, the atmospheric fraction of CO2 is always dominant (>60%) in all cave sections. |
| first_indexed | 2024-12-21T04:40:35Z |
| format | Article |
| id | doaj.art-d73ce2e7d995421b80fee30c6d675ee9 |
| institution | Directory Open Access Journal |
| issn | 0392-6672 1827-806X |
| language | English |
| last_indexed | 2024-12-21T04:40:35Z |
| publishDate | 2018-01-01 |
| publisher | University of South Florida Libraries |
| record_format | Article |
| series | International Journal of Speleology |
| spelling | doaj.art-d73ce2e7d995421b80fee30c6d675ee92022-12-21T19:15:44ZengUniversity of South Florida LibrariesInternational Journal of Speleology0392-66721827-806X2018-01-014719311210.5038/1827-806X.47.1.2141First assessment on the air CO2 dynamic in the show caves of tropical karst, VietnamDuc A. Trinh0Quan H. Trinh1Angel Fernández-Cortés2David Mattey3Javier G. Guinea4Vietnam Atomic Energy InstituteInstitute of Chemistry, Vietnam Academy of Science and TechnologyUniversidad de AlmeríaRoyal Holloway University of LondonMuseo Nacional Ciencias Naturales (MNCN)In this study, air, water, and host rock in show caves in a Vietnam’s karst region was monitored and analyzed to identify the ventilation regime and track the cave air CO2 sources. In general, the studied caves are well ventilated. In dynamic – multiple entrance caves, air ventilation is described with the use of U shape model. In static – single entrance cave, air circulation is explained by cold air trap model. Both ventilation models suggest that air is more circulated in winter than in summer. Seasonally, the cave air CO2 increases from early spring to summer. Value in the deepest part of the single-entrance cave is approximately 1,000 ppmv and 8,000 ppmv in early spring and summer, respectively. In multiple-entrance and wet caves, CO2 level is fairly constant all over the show section, increasing from 500 ppmv in early spring to 2,000 ppmv in summer. Data of microclimate, CO2 content, and particularly δ13C show that cave air, particularly in single entrance cave, has higher CO2 concentration during summer due to a stagnation of cave air circulation and an elevated CO2 input from soil and epikarst. The cave air CO2 increase is also observed after intense rainfalls. A factor that increase cave air CO2 in show caves during the festive days could probably be huma n exhaling but the extent of human factor in these studied cave systems should be further investigated. Cave waters including cave pools and streams mediate CO2 level in wet caves. Above all, the atmospheric fraction of CO2 is always dominant (>60%) in all cave sections.http://scholarcommons.usf.edu/ijs/vol47/iss1/8/Phong Nha – Ke Bangmicroclimatecave air ventilationsoil air CO 2human exhaling |
| spellingShingle | Duc A. Trinh Quan H. Trinh Angel Fernández-Cortés David Mattey Javier G. Guinea First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam International Journal of Speleology Phong Nha – Ke Bang microclimate cave air ventilation soil air CO 2 human exhaling |
| title | First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam |
| title_full | First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam |
| title_fullStr | First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam |
| title_full_unstemmed | First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam |
| title_short | First assessment on the air CO2 dynamic in the show caves of tropical karst, Vietnam |
| title_sort | first assessment on the air co2 dynamic in the show caves of tropical karst vietnam |
| topic | Phong Nha – Ke Bang microclimate cave air ventilation soil air CO 2 human exhaling |
| url | http://scholarcommons.usf.edu/ijs/vol47/iss1/8/ |
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