Changes in Tidal and Barometric Response of Groundwater during Earthquakes—A Review with Recommendations for Better Management of Groundwater Resources
Round 1
Reviewer 1 Report
I read the manuscript titled Earthquake impacts on groundwater evaluated with tidal and barometric response by Chi-Yuen Wang and Michael Manga.
According with the aims and scope of the journal, the manuscript could be published as a Review because, as the authors wrote in their abstract, it is a review about how hydrogeology and earthquakes impact the groundwater response to Earth tides and changes in barometric pressure and barometric tides, also, the current understanding of the mechanisms responsible for the earthquake-induced changes in aquifer confinement and permeability.
In my opinion the title must be added the word “Review” because this paper represents the “state of art” about the groundwater responses under different interactions, the sequence of ideas and results in the manuscript are well developed.
Althogh there are not own results, the description is correctly cited and the authors must write a section of conlusions.
The authors must to check the sequence of the equations, in page 16 line 413, the number (1) in the equation is repeated.
There are references of number of equations in the text that must be corrected.
Author Response
Comment: In my opinion the title must be added the word “Review” because this paper represents the “state of art” about the groundwater responses under different interactions, the sequence of ideas and results in the manuscript are well developed.
Response：We agreed and changed the title of the revised manuscript to "Review of changes in tidal and barometric response of groundwater during earthquakes".
Comment: Although there are not own results, the description is correctly cited and the authors must write a section of conlusions.
Response：We agree and have added a section called "Concluding remarks" at the end of the manuscript.The authors must check the sequence of the equations, in page 16 line 413, the number (1) in the equation is repeated.
Comment: There are references of number of equations in the text that must be corrected.
Response：We checked all the equation numbers in the text.
Reviewer 2 Report
Comments:
1. What are the main hydrogeological factors that influence the response of groundwater to tidal and barometric pressure changes, and how do these factors vary across different aquifer systems?
2. How can water level changes produced by tides and barometric pressure be used to quantify and monitor the effects of earthquakes on groundwater and aquifer properties?
3. How do the signals generated by tides and barometric pressure provide helpful information for evaluating the impacts of unexpected events such as earthquakes, and how do these signals vary across different regions of the Earth's surface?
4. What are some critical challenges associated with extracting tidal and barometric signals from water-level time series, and how can these challenges be addressed?
5. How does hydrogeology influence how aquifers respond to changes in barometric pressure and barometric tides, and what are some critical mechanisms involved in this process?
6. What are the primary ways earthquakes can affect aquifer confinement and permeability, and how do these effects vary across different types of aquifer systems?
7. How can the responses of aquifers to earthquakes be monitored over time, and what are some of the critical considerations when designing a long-term monitoring program?
8. How can analyzing earthquake responses at multiple tidal and barometric frequencies help to improve our understanding of aquifer properties and behavior?
9. What are some of the most promising areas for future research in this field, and what key questions remain unanswered?
10. How might the findings of this research be used to inform decisions related to the management of groundwater resources in earthquake-prone regions, and what are some of the critical policy implications of this work?
Author Response
Comments:
- What are the main hydrogeological factors that influence the response of groundwater to tidal and barometric pressure changes, and how do these factors vary across different aquifer systems?
Response: We had written: “The number of wells and earthquakes studied to date is modest and this limits the ability to identify clear patterns in the magnitude, duration, and mechanism for hydrogeological changes after earthquake. Open questions thus remain about what types of formations are most sensitive to earthquakes, the mechanisms that cause permeability changes, whether there is a frequency-dependence in the seismic waves that cause changes, whether there is a threshold strain or strain-rate amplitude for causing changes, and why some changes recover and others do not.” To this we added: “ Progress in answering these questions is possible by studying more wells and responses to more earthquakes.”
- How can water level changes produced by tides and barometric pressure be used to quantify and monitor the effects of earthquakes on groundwater and aquifer properties?
Response: This is the subject of our review paper, and we present the various models that are used. We are not aware of any other models.
- How do the signals generated by tides and barometric pressure provide helpful information for evaluating the impacts of unexpected events such as earthquakes, and how do these signals vary across different regions of the Earth's surface?
Response: Please see the answers to questions 1 and 2.
- What are some critical challenges associated with extracting tidal and barometric signals from water-level time series, and how can these challenges be addressed
Response: We wrote: “Standard techniques are available for extracting tidal signals from water level time series, such as using Fourier analysis, and readers are referred to some excellent reviews and tutorials on this aspect (e.g., Agnew, 2007; Doan et al., 2006).” To this we added “Important for analysis are long time series, high sampling frequency, and accurate measurements.”
- How does hydrogeology influence how aquifers respond to changes in barometric pressure and barometric tides, and what are some critical mechanisms involved in this process?
Response: We do not understand the second part of this question. The model that we present describes how hydrogeological properties govern the barometric response and the critical mechanisms are in that model.
- What are the primary ways earthquakes can affect aquifer confinement and permeability, and how do these effects vary across different types of aquifer systems?
Response: This is the goal of the section “Mechanisms” and we are not aware of missing proposed mechanisms. We added “With the potential increase in the numbers of wells and earthquakes, the opportunities to apply artificial intelligence-based approaches to the well data will increase, and may eventually allow us to answer some open questions summarized at the beginning of this section, in particular, what types of formations are most sensitive to earthquakes, the mechanisms that cause permeability changes, whether there is a frequency-dependence in the seismic waves that cause changes, whether there is a threshold strain or strain-rate amplitude for causing changes, and why some changes recover and others do not. “
- How can the responses of aquifers to earthquakes be monitored over time, and what are some of the critical considerations when designing a long-term monitoring program?
Response: The economics of this question is beyond the expertise of the authors, but we expanded the conclusions to include a recommendation.
- How can analyzing earthquake responses at multiple tidal and barometric frequencies help to improve our understanding of aquifer properties and behavior?
Response: Our assessment is that “the inclusion of the barometric tides does increase the number of observational constraints, as suggested by McMillan et al. (2019) and implemented by Valois et al. (2022) and Thomas et al. (2023), the uncertainty in the barometric data may propagate into the inverted hydraulic parameters and has so far limited the application of the barometric response to the study of earthquake impacts on the groundwater system.”
- What are some of the most promising areas for future research in this field, and what key questions remain unanswered?
Response: This was the goal of the section “suggested future research”. We think we provided the most promising areas. Did we miss something? We do now address the possible role of AI.
We added “With the potential increase in the numbers of wells and earthquakes, the opportunities to apply artificial intelligence-based approaches to the well data will increase, and may eventually allow us to answer some open questions summarized at the beginning of this section, in particular, what types of formations are most sensitive to earthquakes, the mechanisms that cause permeability changes, whether there is a frequency-dependence in the seismic waves that cause changes, whether there is a threshold strain or strain-rate amplitude for causing changes, and why some changes recover and others do not.”
- How might the findings of this research be used to inform decisions related to the management of groundwater resources in earthquake-prone regions, and what are some of the critical policy implications of this work?
Response: Policy is not our expertise. But our conclusions do outline what changes and why it matters.
To the introduction we added “The coseismic change of the aquifer permeability poses a challenge to the management of groundwater resources, which requires accurate knowledge of the aquifer properties. These changes often cause aquifers to leak (e.g., Wang et al., 2016; Zhang-Wang et al., 2019; Zhang-Shi et al., 2019), which in turn may lead to exchanges of groundwater among different aquifers or between aquifers and the ground surface (Wang et al., 2018; Barbour et al., 2019). While most of these changes are reversible and recover to their pre-seismic values after several weeks or months (Elkhoury et al., 2006), some are long-lasting and do not recover to the pre-seismic level after many years (e.g., Liao et al., 2015; Zhang et al., 2021; Wang, 2022). In such cases, the management of groundwater resources based on the knowledge of the pre-seismic aquifer properties may lead to erroneous decisions. Because large earthquakes may occur unexpectedly and because aquifer leakage may cause hazardous wastes to spread from their repositories to groundwater resources, urgent actions may often be required. The tidal and barometric response method reviewed in this paper make it possible for real-time, large-scaled, quantitative re-evaluation of the aquifer properties and the safety of groundwater resources after large earthquakes.”
Reviewer 3 Report
Thank you for providing me with the opportunity to review the paper on earthquake hydrology written by two of the leading experts in the field. As requested, I have carefully read the manuscript and have prepared a review report highlighting my thoughts on the content.
While the authors are undeniably knowledgeable on the subject, I believe that the paper requires a significant revision before it can be considered for publication. My main concern is that the level of analysis provided is far too superficial, given the authors' expertise and reputation in the field.
One major issue that stood out to me was the authors' failure to incorporate recent developments in the field, as (for instance) the possible contribution of the use of artificial intelligence-based approaches. This is a significant oversight given the tremendous progress that has been made in this area over the past several years. I believe that a more comprehensive review that includes recent developments in this field would significantly improve the paper's contribution to the field.
Additionally, I found the statement included in the conclusion apologizing for any missed papers to be somewhat unprofessional. As leading experts in the field, the authors should have made a more substantial effort to ensure that they were aware of all relevant papers and incorporated them into their analysis.
Furthermore, the lack of coverage of recent developments in the literature renders the paper's "suggested future studies" section weak.
Overall, I believe that this paper has the potential to make a valuable contribution to the field of earthquake hydrology. However, I must recommend a significant revision to address the issues highlighted above.
Author Response
Comment: One major issue that stood out to me was the authors' failure to incorporate recent developments in the field, as (for instance) the possible contribution of the use of artificial intelligence-based approaches. This is a significant oversight given the tremendous progress that has been made in this area over the past several years. I believe that a more comprehensive review that includes recent developments in this field would significantly improve the paper's contribution to the field.
Response: In response to the reviewer's comment that we did not review the use of artificial intelligence-based approaches to the topic of our study, we looked through the recent publications on using artificial intelligence-based approaches for earthquake-related studies. While AI has been used in earthquake prediction (e.g., Galkina and Grafeeva, 2019; Beroza et al., 2021) and in the prediction of earthquake hazards (Gitis and Derendyaev, 2019; Ghani et al., 2022), it has not been used in the topics of study reviewed in our paper, i.e., earthquake-induced changes in groundwater response to Earth tides or the barometric pressure. Meanwhile, we have added a paragraph in the section on Suggested future studies suggesting that the artificial intelligence-based approach may be used to study the topics in this review in the near future.
Comment: Additionally, I found the statement included in the conclusion apologizing for any missed papers to be somewhat unprofessional. As leading experts in the field, the authors should have made a more substantial effort to ensure that they were aware of all relevant papers and incorporated them into their analysis.
Response: We agree. We have added more references to the revised manuscript and removed the 'apologizing clause' from the acknowledgement.
Comment: Furthermore, the lack of coverage of recent developments in the literature renders the paper's "suggested future studies" section weak.
Response: We have added a paragraph in the section "Suggested future studies" on the potential applications of artificial intelligence-based approach in the study of earthquake-induced changes in the groundwater response to Earth tides and barometric pressure.
Round 2
Reviewer 2 Report
The authors have well addressed my comments; I suggest this manuscript can be accepted for publication in the Water journal.
Author Response
OK.
Reviewer 3 Report
While I recognize some efforts of the Authors in improving their manuscript, their response about the lack of studies using AI for problems dealing with earthquake hydrology could not be considered fully accurate, as demonstrated, for instance, by the following papers published in the last years.
2023. “Deep learning for earthquake hydrology? Insights from the karst Gran Sasso aquifer in central Italy” (doi: 10.1016/j.jhydrol.2022.129002)
2021. “Detection of possible hydrological precursor anomalies using long short-term memory: A case study of the 1996 Lijiang earthquake” (doi: 10.1016/j.jhydrol.2021.126369)
2021. “Reconstruction of groundwater level at Kumamoto, Japan by means of deep learning to evaluate its increase by the 2016 earthquake” (doi: 10.1088/1755-1315/851/1/012032)
The Authors may consider them as recent emergent examples of the application of AI in the context of the studied topic.
Author Response
We have mentioned these references in our paper (Lines 721-725) and included them in our reference list.
