the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Spring water anomalies before two consecutive earthquakes (Mw 7.7 and Mw 7.6) in Kahramanmaraş (Türkiye) on 6 February 2023
Sedat Inan
Hasan Cetin
Nurettin Yakupoglu
Abstract. Understanding earthquake phenomena is always challenging. Search for reliable precursors of earthquakes are important but requires systematic and long-time monitoring employing multi-disciplinary techniques. In search of possible precursors, we obtained commercially bottled spring waters dated before and after the earthquakes of 6 February 2023. Hydrogeochemical precursors have been detected in commercially bottled natural spring waters (Ayran Spring and Bahçepınar Spring) which are at a distance of about 100 km and 175 km from the epicenters of the Mw 7.7 and Mw 7.6 Kahramanmaraş (Türkiye) Earthquakes of 6 February 2023, respectively. The available water samples cover the period from March 2022 to March 2023. The pre-earthquake anomaly is characterized by an increase in electrical conductivity and major ions (Ca2+, Mg2+, K+, Na+, Cl–, and SO42-) compared to the background for Ayran Spring water samples. The pre-earthquake anomaly lasted for at least six months. The anomaly in major ions sharply declined and the ion content approached the background values about two weeks after the earthquakes. Although only 6.5 kilometers away from the Ayran Spring, the bottled water samples of the Bahçepınar Spring did not show any anomalies in electrical conductivity; therefore, the samples were not analyzed for ion content. Bahçepınar water is collected from shallow boreholes dug into alluvial deposits which we believe are decoupled from the basement rocks and this may be the reason for the lack of abnormal water chemistry prior to the earthquakes. This attests to the fact that sampling locations are very important in the detection of possible earthquake precursors. Results on the Ayran spring water samples indicate that spring water chemical anomalies of discrete samples may provide valuable information on pre-earthquake crustal deformation. Monitoring of spring waters, along with other monitoring techniques in a multidisciplinary network, and for a sufficiently long time, could potentially enable obtaining reliable proxy indicators of pre-earthquake crustal deformation.
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Sedat Inan et al.
Status: open (until 15 Oct 2023)
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RC1: 'Comment on nhess-2023-133', Giovanni Martinelli, 16 Aug 2023
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I have found interesting the manuscript https://doi.org/10.5194/nhess-2023-133 submitted by Inan et al. In particular Authors reported that commercially packaged spring water samples dated prior to and subsequent to the seismic events occurring on February 6,2023 were analyzed. Hydrogeochemical precursors have been identified in bottled natural spring waters originating from Ayran Spring and Bahçepınar Spring. These springs are located around 100 km and 175 km away from the epicentres of the Mw 7.7 and Mw 7.6 Kahramanmaraş (Türkiye) Earthquakes that occurred on 6 February 2023, respectively. The water samples at hand encompass the temporal span from March 2022 to March 2023. The pre-earthquake anomaly is distinguished by an elevation in electrical conductivity and the presence of significant ions (such as Ca2+, Mg2+, K+, Na+, Cl–, and SO42-) in Ayran Spring water samples, as opposed to the baseline conditions. The concentration of main ions exhibited a significant decrease, and the levels of ions gradually approached the background values approximately fourteen days following the occurrence of the earthquakes. The Bahçepınar water is obtained from shallow boreholes that have been excavated in alluvial deposits. These deposits are believed to be disconnected from the underlying basement rocks, which could explain the absence of anomalous water chemistry prior to the occurrence of earthquakes. This observation substantiates the significance of sampling locations in the identification of potential indicators of earthquakes. The findings pertaining to the Ayran spring water samples suggest that the chemical anomalies observed in discrete samples of spring water can offer significant insights about the pre-earthquake deformation processes of the Earth's crust. The implementation of long-term monitoring techniques, such as the monitoring of spring waters, within a multidisciplinary network, holds the potential to yield credible proxy indicators of pre-earthquake crustal deformation. Continuous earthquake monitoring networks of geophysical and geochemical parameters should be established and run for a sufficiently long time.The paperi is well organized and I hope i twill be soon published after the addition of further References in which geochemical variations have been observed in geofluids (in general) in Turkey.
Citation: https://doi.org/10.5194/nhess-2023-133-RC1 -
CC1: 'Reply on RC1', Sedat Inan, 16 Aug 2023
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Thank you Giovanni Martinelli for your kind words about our manuscript. We will add further relevant references as you may suggest.
Citation: https://doi.org/10.5194/nhess-2023-133-CC1 -
AC1: 'Reply on CC1', Sedat Inan, 16 Aug 2023
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Furthermore, Inan et al (2010) and Inan et al (2012c) as cited in the manuscript mention hydrogeochemical anomalies before Mw 4.2 and Mw 4.8 earthquakes in Aegean Extensional Province and the 23 October Mw 7.2 Van earthquake.
Citation: https://doi.org/10.5194/nhess-2023-133-AC1 -
RC2: 'Reply on AC1', Giovanni Martinelli, 16 Aug 2023
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I hope the paper will be quickly accepted and published after the accepted addition.
Citation: https://doi.org/10.5194/nhess-2023-133-RC2 -
AC2: 'Reply on RC2', Sedat Inan, 16 Aug 2023
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Thank you for your encouragement and positive guidance.
Citation: https://doi.org/10.5194/nhess-2023-133-AC2
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AC2: 'Reply on RC2', Sedat Inan, 16 Aug 2023
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RC2: 'Reply on AC1', Giovanni Martinelli, 16 Aug 2023
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AC1: 'Reply on CC1', Sedat Inan, 16 Aug 2023
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CC1: 'Reply on RC1', Sedat Inan, 16 Aug 2023
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RC3: 'Comment on nhess-2023-133', Anonymous Referee #2, 28 Sep 2023
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The manuscript "Spring water anomalies before two consecutive earthquakes (Mw 7.7 and Mw 7.6) in Kahramanmaraş (Türkiye) on 6 February 2023," by Inan and colleagues, reports the description of geochemical anomalies in a spring before the 2 earthquakes on February 6, 2023. The article provides a comprehensive overview of the current state of knowledge, detailing the methodology employed and presenting the obtained results effectively. I think that publishing the observations made in this study is crucial for improving our understanding of the interactions between the seismic cycle and fluid circulation. It deserves publication in a scientific journal. However, a comprehensive and in-depth analysis of some aspects related to the “normal” hydrogeological cycle is necessary to eliminate doubts and uncertainties in the interpretation of the data.
The pre-earthquake anomalies, if confirmed, are clear and well-evident. So, I will now focus on the criticisms and issues to enhance the robustness of the study.
There is a complete absence of a description of the hydrogeological settings of the examined area and the geochemical characterization of the spring waters. It is necessary to place the analysed springs in a regional structural-geological and hydrogeological context.
The study's main weakness is the lack of data from March to September 2022 and historical data predating March 2022. Having data for this period could significantly enhance the comprehensiveness and depth of the analysis. The analysis of the historical time series of the spring could suggest a seasonal pattern. The data for March 2023 is very similar to that of March 2022. What happens in September and October 2023? The historical data from August 29, 2012, is insufficient to exclude cyclical and seasonal behaviour like that of 2022. It would be useful to obtain historical data within the same time interval where anomalies were recognized or extend the time series throughout 2023.
Could the rainfall after earthquakes 1 and 2 have diluted the spring waters? What is the recharge/discharge cycle of this spring, and what are the factors that determine it?
Suggestions for improvement:
- Include a hydrogeological and hydrogeochemical framework of the area.
- Enhance (if possible) Figure 2 with a circulation scheme and hydrogeological map.
- Include in the "Results and Discussion" section the geochemical characterization of the studied springs (e.g., Langelier Ludwig diagram - all samples).
- The electrical conductivity values of Ayran appear to be shifting towards mixing with waters like those of Bahcepinar. Have you assessed this possibility?
- The time axis length in Figure 3 is not consistent with time. Insert a break between March and September 2022 or adjust the proportions accordingly.
- Extend the time series to at least a year (using either new or historical data).
- In Figure 3 Cont., clarify the meaning of "Average Rainfall."
- Consider combining Figure 3 and Figure 3 Cont.
It's challenging to hypothesize interpretative models with data from just one spring. It is necessary to exclude trends related to the hydrogeological cycle and then evaluate possible phenomena of mixing between different aquifers (e.g., shallow vs. deep) or variations in hydrodynamic properties related to the preparatory phases of the main seismic events. The analysis of stable isotopes of the water molecule could help understand potential mixing processes. Despite the samples not being acidified, an attempt to analyse trace elements should be made.
Citation: https://doi.org/10.5194/nhess-2023-133-RC3 -
AC3: 'Reply on RC3', Sedat Inan, 28 Sep 2023
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The referee kindly mentions the below paragraph at the beginning of the manuscript evaluation report.
The article provides a comprehensive overview of the current state of knowledge, detailing the methodology employed and presenting the obtained results effectively. I think that publishing the observations made in this study is crucial for improving our understanding of the interactions between the seismic cycle and fluid circulation. It deserves publication in a scientific journal.
We thank the referee for supportive and encouraging remarks. We also believe that publishing these observations are crucial as they are eye-opening and will lead to further studies by us and possibly others in near future; exactly as the referee suggests.
Here we would like to reply to what the referee has raised as a possible issue which is the possibility of seasonality of the AYRAN spring water the major ions content.
In the manuscript, in addition to analyses of the available samples, we have mentioned - on Page 14. Lines 347-348 - that we have also utilized the information on major ion contents for the Ayran water sample analyzed 10 years ago in 2012. we copied the section (Page 14. Lines 347-348) below.
“We have also obtained a chemical analysis report on AYR water submitted with the business license application of the company dated 29 August 2012. The chemical analysis data of the samples collected more than 10 years ago include values only for Na+, Cl–, and SO42– as 3.86, 3.12, and 8.37 mg/l, respectively. These values are very close to the analysis result of the AYR water sample dated 8 March 2022 (AYR 1 which is the oldest sample in our data set) and the AYR water samples collected after 15 February (Table 2); confirming that these samples represent background values for the AYR spring water.”
The analysis report dated August 2012 was taken also as a supporting evidence for our interpretation that the March 2022 and March 2023 samples represent chemical background before manifestation of pre-earthquake crustal deformation and after the February 2023 Earthquakes earthquake, respectively. Seasonal change in the major ion content does not seem to exist because we have sample both from March (2022 and 2023) and August 2012 which have comparable content for at least Na+, Cl–, and SO4-2. The pdf of the business license issued on 29 August 2012 and chemical analysis on which this business certificate was issued are attached.
Therefore, we do believe based on close similarity of major ion contents of samples from March (2022, 2023) and August (2012), that the changes in major ions are not due to seasonal effects are related to pre-earthquake crustal deformation as we have (and many others also have) shown in previous publications.
Extending the time series cannot be backward as this is not possible ,but as we will continue our research for future publications, we will obtain future samples from the Ayran spring and conduct some analyses to further our understanding of the hydrogeochemical cycle.
At the moment our main aim is to publish these observations and our interpretations of these anomalies in light of seismicity. Once published, we believe that this paper will make a start point for future complimentary studies as the referee has suggested.
We appreciate referee's constructive criticism and open-minded approach.
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CC2: 'Comment on nhess-2023-133', Vivek Walia, 03 Oct 2023
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The authors have presented an interesting study on fluctuations in ion concentrations in natural spring water as a precursor for the devastating Mw 7.7 and Mw 7.6 Kahramanmaraş (Türkiye) earthquakes of 6 February, 2023. The novelty of the study rests in the fact that despite the absence of continuous geochemical monitoring in the region, the authors have found a way to look for precursory anomalies indirectly, studying commercially available bottled water collected from natural springs close to the epicentres of the earthquakes. The manuscript is structured well and the main idea is presented clearly. I would recommend acceptance of the article after some revision.
General comments:
- The manuscript should be checked thoroughly and inconsistencies in grammar, tenses of verbs, prepositions, etc. should be corrected.
- There are some prominent repetitions of entire sentences or parts of sentences in Abstract, Conclusions, and the last paragraph Result and Discussion. This should be edited.
Specific comments are mentioned within the manuscript.
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AC4: 'Reply on CC2', Sedat Inan, 03 Oct 2023
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Dr. Vivek Walia
Thank you for your encouragement and constructive view and review on our manuscript. We will do review the manuscript and make all the corrections as you have suggested.
Citation: https://doi.org/10.5194/nhess-2023-133-AC4
Sedat Inan et al.
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