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Ascending Volcanic Fluids Portended by Spatiotemporal Variations of the Earthquake Mechanisms in the Tatun Volcano Group in Northern Taiwan
Author(s) -
Pu HsinChieh,
Lin ChengHorng,
Lee HsiaoFen,
Lai YaChuan,
Chang LiChin,
Shih MinHung
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl091686
Subject(s) - volcanism , volcano , geology , hydrothermal circulation , seismology , group (periodic table) , geochemistry , tectonics , chemistry , organic chemistry
To investigate the possible precursors of surface volcanism, we examined 2,473 earthquake focal mechanisms and the relative abundance of total sulfur (S t ) to carbon dioxide (CO 2 ) in the Tatun Volcano Group in the northern Taiwan, where various reports have indicated ongoing volcanic activities. We analyzed three time‐dependent observations: the occurrence rate of both shallower (0–2 km) reverse‐type earthquakes and deeper (2–4 km) normal‐type earthquakes, as well as the surface S t /CO 2 ratio. Among these observations, we found a series of similar variations, which progressed in a stepwise manner as the depth range of the observation decreased. To interpret the spatiotemporal variations of three observations, we construct a model involving the ascending volcanic fluids in the conduit and hydrothermal layer. The significant variations in deeper and shallower faulting behaviors portend a double warning of surface volcanism associated with the ascending fluids at ∼4 and ∼1 month(s) ago, respectively.