Evaluating the responses of alluvial and bedrock aquifers to earthquakes (ML5.1 and ML5.8) using hydrological and environmental tracer data

Kaown, Dugin; Koh, Dong‐Chan; Kim, Heejung; Koh, Hee Jae; Kim, Jaeyeon; Lee, Sanghoon; Park, In-Woo; Lee, Kang‐Kun

doi:10.1007/s10040-019-01966-5

Cited by 13 publications

(12 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the Gyeongju area, δ 13 C values of dissolved inorganic carbon (DIC) in groundwater samples have been reported with the range of −12.72 to −17.17‰ (ref. 42 ), which is included in the range of our results (Fig. 4).…”

Section: Resultsmentioning

confidence: 89%

Mantle degassing along strike-slip faults in the Southeastern Korean Peninsula

Lee

Kim

Kagoshima

et al. 2019

Sci Rep

View full text Add to dashboard Cite

On September 12, 2016, a ML 5.8 earthquake hit Gyeongju in the southeastern part of the Korean Peninsula (SeKP), although the area is known to be far from the boundary of the active plate. A number of strike-slip faults are observed in heavily populated city areas (e.g., Busan, Ulsan, Pohang, and Gyeongju). However, dissolved gases related to the active faults have rarely been studied despite many groundwater wells and hot springs in the area. Here we report new results of gas compositions and isotope values of helium and carbon dioxide (CO2) in fault-related fluids in the region. Based on gas geochemistry, the majority of gas samples are abundant in CO2 (up to 99.91 vol.%). Measured 3He/4He ratios range from 0.07 to 5.66 Ra, showing that the mantle contribution is up to 71%. The range of carbon isotope compositions (δ13C) of CO2 is from −8.25 to −24.92‰, showing mantle-derived CO2 is observed coherently where high 3He/4He ratios appear. The weakening of faults seems to be related to enhanced pressures of fluids containing mantle-derived helium and CO2 despite the ductile lower crust underneath the region. Thus, we suggest that the SeKP strike-slip faults penetrate into the mantle through ductile shearing.

show abstract

Section: Resultsmentioning

confidence: 89%

Mantle degassing along strike-slip faults in the Southeastern Korean Peninsula

Lee

Kim

Kagoshima

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…After the main shock, an abrupt water level deviation between wells PX-1 and PX-2 of approximately 740 m occurred. Hydrological responses after earthquake events have also been reported in several studies 21 – 29 . For example, an increase in the streamflow was observed after the 2003 San Simeon (California) Earthquake 27 while other studies identified new streams and springs that originated from groundwater in adjacent mountains after the 2014 South Napa M W 6.0 earthquake in California, USA 30 .…”

Section: Introductionmentioning

confidence: 56%

Earthquakes and very deep groundwater perturbation mutually induced

Kaown

Lee

Kim

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

We report unique observations from drilling and hydraulic stimulation at a depth of approximately 4.3 km in two Enhanced Geothermal System (EGS) wells at the Pohang EGS site, South Korea. We surveyed drilling logs and hydraulic stimulation data, simulated pore pressure diffusion around the fault delineated by seismic and drilling log analyses, conducted acoustic image logging through the EGS wells, observed significant water level drops (740 m) in one of the two EGS wells, and obtained hydrochemical and isotopic variation data in conjunction with the microbial community characteristics of the two EGS wells. We discuss the hydraulic and hydrochemical responses of formation pore water to a few key seismic events near the hypocenter. We focused on how the geochemistry of water that flowed back from the geothermal wells changed in association with key seismic events. These were (1) a swarm of small earthquakes that occurred when a significant circulation mud loss occurred during well drilling, (2) the MW 3.2 earthquake during hydraulic stimulation, and (3) the MW 5.5 main shock two months after the end of hydraulic stimulation. This study highlights the value of real-time monitoring and water chemistry analysis, in addition to seismic monitoring during EGS operation.

show abstract

“…Here we discuss the response of the groundwater composition. Most measurements of groundwater composition took place after the earthquakes (Kim et al 2019;Kaown et al 2019). Fortunately, some wells (Fig.…”

Section: Koreamentioning

confidence: 99%

“…These include consistent post-seismic 3 and SO 2− 4 in the waters from the studied wells from 2014 to 2017. Measurements in the first three years were made before the earthquake; the one in 2017 was made after the earthquake (modified from Kaown et al 2019) increase of the concentrations of Na + , Ca +2 , HCO − 3 and SO 2− 4 (well KW5-2), consistent post-seismic decrease in the concentrations of the four same ions (well KW7-2), and clear post-seismic increases in Na + and Ca +2 (well KW6-2), but no change in HCO −1 3 or SO 2− 4 . The inconsistent changes of groundwater composition after the earthquake among these wells suggest that the wells may be opened to different and isolated fractures in the basement rocks.…”

Section: Koreamentioning

confidence: 99%

See 1 more Smart Citation

Groundwater and Stream Composition

Wang

Manga

2021

Lecture Notes in Earth System Sciences

View full text Add to dashboard Cite

Changes of groundwater chemistry have long been observed. We review some studies of the earthquake-induced changes of groundwater and streamflow composition. When data are relatively abundant and the hydrogeology is relatively simple, the observed changes may provide valuable insight into earthquake-induced changes of hydrogeological processes. Progress in this aspect, however, has been slow not only because systematic measurements are scare but also because of the distribution of chemical sources and sinks in the crust are often complex and unknown. Most changes are consistent with the model of earthquake-enhanced groundwater transport through basin-wide or local enhanced permeability caused by earthquake-induced breaching of hydrologic barriers such as aquitards, connecting otherwise isolated aquifers or other fluid sources, leading to fluid source switching and/or mixing. Because the interpretation of earthquake-induced groundwater and stream compositions is often under-constrained, multi-disciplinary approaches may be needed to provide a better constrained interpretation of the observed changes.

show abstract

Evaluating the responses of alluvial and bedrock aquifers to earthquakes (ML5.1 and ML5.8) using hydrological and environmental tracer data

Cited by 13 publications

References 57 publications

Mantle degassing along strike-slip faults in the Southeastern Korean Peninsula

Mantle degassing along strike-slip faults in the Southeastern Korean Peninsula

Earthquakes and very deep groundwater perturbation mutually induced

Groundwater and Stream Composition

Contact Info

Product

Resources

About