Earthquake Observation through Groundwater Monitoring in South Korea

Abstract:

According to previous researches, the influence of the some earthquakes can be detected by groundwater monitoring. Even in some countries groundwater monitoring is being used as an important tool to identify earthquake precursors and prediction measures. Thus, in this study we attempt to catch the anomalous changes in groundwater produced by earthquakes occurred in Korea through the National Groundwater Monitoring Network (NGMN).

For observing the earthquake impacts on groundwater more effectively, from the National Groundwater Monitoring Network we selected 28 stations located in the five earthquake-prone zones in South Korea. And we searched the responses to eight earthquakes with M ≥2.5 which occurred in the vicinity of five earthquake-prone zones in 2012. So far, we tested the groundwater monitoring data (water-level, temperature and electrical conductivity). Those data have only been treated to remove barometric pressure changes. Then we found 29 anomalous changes, confirming that groundwater monitoring data can provide valuable information on earthquake effects.

To identify the effect of the earthquake from mixture signals of water-level, other signals must be separated from the original data. Periodic signals will be separated from the original data using Fast Fourier Transform (FFT). After that we will attempt to separate precipitation effect, and determine if the anomalies were generated by earthquake or not.