前言地球化学方法纳入地震预报计划以来已近十年,正常观测的主体是观测溶于地下水的成分和观测从地球内部直接或间接释放出成分的时间变化。参与地球化学观测、研究的部门有大学和地质调查所、国立防灾科学技术中心等。该领域的现状是处于在积累检测前兆现象观测数据的同时,下大力开发新的观测方法的阶段。本文是以观测时间最长、观测地点最多的 Preface Geochemical approaches have been in place for nearly a decade since the earthquake prediction program. The main body of normal observations is to observe the composition of groundwater dissolved in water and to observe the temporal changes in the composition that are released directly or indirectly from inside the Earth. Geochemical observation and research departments include universities and geological survey institutes, and national disaster prevention science and technology centers. The current situation in this area is at the stage of accumulating the observation data of precursor phenomena and vigorously developing new observation methods. This article is based on the longest observation time, the most observation sites