Pilot-Scale Groundwater Monitoring Network for Earthquake Surveillance and Forecasting Research in Korea

Abstract

Although there is skepticism about the likelihood of predictive success, research on the prediction of an earthquake through precursory changes in natural parameters, including groundwater, has continued for decades. One of the promising precursors is the changes in groundwater, i.e., the level and composition of groundwater, and the monitoring networks are currently operated to observe earthquake-related changes in several countries situated at the seismically active zone. In Korea, the seismic hazards had not been significantly considered for decades since the seismic activity was relatively low; however, the public demands on the management and prediction of earthquakes were raised by two moderate-size earthquakes which occurred in 2016 and 2017. Since then, a number of studies that were initiated in Korea, including this study to establish a pilot-scale groundwater-monitoring network, consisted of seven stations. The network is aimed at studying earthquake-related groundwater changes in the areas with relatively high potentials for earthquakes. Our study identified a potential precursory change in water levels at one particular station between 2018 and 2019. The observed data showed that most monitoring stations are sufficiently isolated from the diurnal natural/artificial activities and a potential precursory change of water level was observed at one station in 2018. However, to relate these abnormal changes to the earthquake, continuous monitoring and analysis are required as well as the aid of other precursors including seismicity and geodetic data.

Multiparametric stations for real-time monitoring and long-term assessment of natural hazards

“…Some infrastructures are capable of (near) real-time continuous monitoring with various data acquisition frequencies. Certain are devoted to examining mainly water level, temperature and electrical conductance of groundwater (Hosono et al, 2019;Lee et al, 2021), others of thermal springs (Popit et al, 2005). There are rare examples of continuous monitoring of gas composition (radon, He, Ar, N, CH 4 ) associated with thermal springs (e.g., Chaudhuri et al, 2013).…”

Groundwater and Dissolved Gases Geochemistry in the Pesaro-Urbino Province (Northern Marche, Central Italy) as a Tool for Seismic Surveillance and Sustainability

“…Even though the prediction of earthquakes is challenging, promising geochemical precursors were recently recognized in different geological and geodynamic contexts worldwide, through long-term (periodical or continuous) monitoring of various chemical, physical, isotopic, or hydrogeological parameters, e.g., [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Precursors (or tracers) of seismic events can be defined as a "quantitatively measurable change in an environmental parameter occurring prior to the mainshock" [26][27][28][29][30]. These changes may occur from months to weeks prior to the event or concurrently and are generally observed for earthquakes having a magnitude higher than 4 Mw [9,14,30].…”

“…A detailed and continuous geochemical characterization of the circulating groundwaters is of pivotal importance to highlight possible modifications in terms of water chemistry and isotopes. Reliable precursory signals of seismic activity can, thus, be recorded, being, in most cases, extremely site-specific and strictly connected to the geological, hydrogeological, and tectonic characteristics of a given area [25][26][27]30].…”

Influence of the Gyeongju Earthquake on Observed Groundwater Levels at a Power Plant

“…In addition to considerations on the influence of earthquakes on groundwater levels, there are also studies on the behavior of groundwater levels as a precursor to seismic activity [26][27][28][29][30][31][32][33]. The motivating concept is that changes due to seismic activity, such as a foreshock, will induce ground strains and deformations that allow for groundwater level changes.…”

“…One study suggested the installation of additional groundwater monitoring wells to help with earthquake forecasting, but then that would beg the question of acceptance criteria for an upcoming earthquake [25]. Another study offered a magnitude-dependent relationship for observable differences [27]. These could be crucial for critical power plants as well as radioactive waste repositories.…”