Variations in the Cl, SO4, δD and δ^18O in Water from Thermal Springs near Acapulco, Guerrero, Mexico, Related to Seismic Activity

墨西哥Acapulco地區溫泉水之氯、硫酸根離子與氫氧同位素變化與地震活動之關連

Alejandro Ramirez-Guzman ； Yuri A. Taran ； Ruben Bernard ； Edith Cienfuegos ； Pedro Morales

《Terrestrial, Atmospheric and Oceanic Sciences》 16卷4期 (2005/10) Pp. 731-743

並列摘要

Chemical and isotopic analyses of waters from 4 thermal springs of the Guerrero Pacific coast, the most seismically active area in Mexico, were weekly performed during a period of 1.5 years (October 2002-March 2004). Within the same time interval more than 150 earthquakes with 3.5 ＜ M ＜ 5.3 occurred in the area. The data display several anomalies in Cl, SO4, δD and δ^18O, always immediately after an event, with a relaxation time of 3-4 weeks. The responses occurred only with earthquakes having an estimated epicentral site very close or almost coincident with the location of a spring. These results indicate that: 1) at least for earthquakes with M＜5.3 within the Guerrero ”seismic gap” there were no precursors in the chemical (ionic) and isotopic composition of thermal waters (on the weekly basis); 2) two groups of springs near Acapulco, Dos Arroyos and Paso Real, are sensitive to seismic activity and therefore further monitoring of these springs may help to unravel the mechanisms of the ”hydro-seismo-interaction” in the area.

並列關鍵字

Thermal springs ； Geochemistry ； Seismic activity ； Mexico