Large‐scale organization of carbon dioxide discharge in the Nepal Himalayas. Issue 18 (18th September 2014)

• Record Type: Journal Article
• Authors: Girault, Frédéric; Bollinger, Laurent; Bhattarai, Mukunda; Koirala, Bharat Prasad; France‐Lanord, Christian; Rajaure, Sudhir; Gaillardet, Jérôme; Fort, Monique; Sapkota, Soma Nath; Perrier, Frédéric
• Is Part Of: Geophysical research letters. Volume 41:Issue 18(2014:Sep.)
• Page Start: 6358
• Page End: 6366
• Publication Date: 2014-09-18
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2014GL060873
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Gaseous carbon dioxide (CO₂) and radon‐222 release from the ground was investigated along the Main Central Thrust zone in the Nepal Himalayas. From 2200 CO₂ and 900 radon‐222 flux measurements near 13 hot springs from western to central Nepal, we obtained total CO₂ and radon discharges varying from 10⁻³ to 1.6 mol s⁻¹ and 20 to 1600 Bq s⁻¹, respectively. We observed a coherent organization at spatial scales of ≈ 10 km in a given region: low CO₂ and radon discharges around Pokhara (midwestern Nepal) and in the Bhote Kosi Valley (east Nepal); low CO₂ but large radon discharges in Lower Dolpo (west Nepal); and large CO₂ and radon discharges in the upper Trisuli Valley (central Nepal). A 110 km long CO₂‐producing segment, with high carbon isotopic ratios, suggesting metamorphic decarbonation, is thus evidenced from 84.5°E to 85.5°E. This spatial organization could be controlled by geological heterogeneity or large Himalayan earthquakes.</p> </abstract>