Skip to content

Diffuse CO2 degassing and its origin in the Tatun Volcano Group, Northern Taiwan

Ching-Chou Fu 1, Kuo-Hang Chen1, Kuo-Wei Wu1, Pei-Ling Wang2, Li-Hung Lin3, Vivek Walia4

  • Affiliations:  1Institute of Earth Sciences, Academia Sinica, Taiwan, 2Institute of Oceanography, National Taiwan University, Taiwan, 3Department of Geosciences, National Taiwan University, Taiwan, 4National Center for Research on Earthquake Engineering, NARL, Taiwan 

  • Presentation type: Poster

  • Presentation time: Friday 16:30 - 18:00, Room Poster Hall

  • Poster Board Number: 255

  • Programme No: 3.17.30

  • Theme 3 > Session 17

Abstract

The Tatun Volcano Group (TVG), located in northern Taiwan, is an area of significant volcanic and geothermal activity. This study systematically investigates the spatial distribution and sources of diffuse carbon dioxide (CO2) emissions to quantify degassing processes and evaluate their correlation with volcanic activity. A total of 448 soil gas flux measurements, conducted over a 10 km² area using the closed-chamber method, revealed substantial CO2 emissions from both hydrothermal and non-hydrothermal zones. The identification of well-developed fractures and degassing structures in non-hydrothermal areas highlights their role in facilitating deep-seated gas migration to the surface. Isotopic analyses of carbon and helium confirmed the mantle-derived origin of the emitted CO2, indicating contributions from magmatic and crustal sources. High-CO2 flux zones interacting with shallow hydrothermal systems were linked to carbonate precipitation and altered isotopic signatures, suggesting the presence of shallow aquifers. Temporal analysis of soil CO2 flux in the Dayoukeng (DYK) hydrothermal area from 2009 to 2024 showed a 210% expansion of degassing zones, correlating with elevated soil temperatures and water vapor anomalies. These findings emphasize the need for continuous monitoring to assess volcanic hazards, particularly in high-risk non-hydrothermal areas, and contribute valuable insights into TVG's degassing mechanisms and underlying magmatic processes.