the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 18 Jun 2025
Understanding extreme-wave hazards on high-energy coasts requires a standardised approach to field data collection: Analysis and recommendations
Abstract. Coastal boulder deposits provide vital information on extreme wave events. They are crucial for understanding storm and tsunami impacts on rocky coasts, and for understanding long-term hazard histories. But study of these deposits is still a young field, and growth in investigation has been rapid, without much contact between research groups. Therefore, inconsistencies in field data collection among different studies hinder cross-site comparisons and limit the applicability of findings across disciplines. This paper analyses field methodologies for coastal boulder deposit measurement based using an integrated database (ISROC-DB), demonstrating inconsistencies in current approaches. We use the analysis as a basis for outlining protocols to improve data comparability and utility for geoscientists, engineers, and coastal planners. Using a standardised and comprehensive set of measurements, with due attention to precision and reproducibility, will help ensure complete data retrieval in the field. Applying these approaches will further ensure that data collected at different times and/or locations, and by different groups, is useful not just for the study being undertaken, but for other researchers to analyse and reuse. This is fosters development of the large, internally consistent datasets that are the basis for fruitful meta-analysis; and is particularly timely given increasing focus on longitudinal monitoring of coastal change. By recommending a common set of measurements, adaptable to available equipment and personnel, this work aims to support accurate and thorough coastal boulder deposit documentation, enabling broader applicability and future-proofed datasets. Field protocols described and recommended here also apply as best practices for coastal geomorphology field work in general.
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Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
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Preprint
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
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Supplement
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- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2025-1913', Giovanni Scardino, 11 Jul 2025
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AC3: 'Reply on RC1', Rónadh Cox, 26 Aug 2025
Thank you for your thoughtful comments on our manuscript. We have incorporated them into our revised manuscript, as follows:
1. You pointed out that we should provide more specific information in the Abstract about the kinds of field protocols being suggested. We have revised the text at line 52 to read:
“Using standardised and comprehensive data reporting with due attention to precision and reproducibility—including site characteristics, boulder dimensions, complete positional data, tide characteristics, and geodetic and local topographic datum information—will help ensure complete data retrieval in the field.”
2. We have also replaced the phrase “longitudinal monitoring” in the abstract with “long-term monitoring”, in response to your request for greater clarity.
3. You stated both in the PDF and in your reviewer comments that we should include information about chronologic constraints on landscape reconstruction. To that end, we have edited the first paragraph in section 6 (lines 740 et seq.), which now reads as follows:
“Determining emplacement age(s) of coastal boulder deposits, and (for ancient example) establishing chronological constraints on the landscape at the time of boulder displacement are very desirable goals. Such data permit construction of event chronologies, and by comparison with other archives such as wave climate or earthquake records, can help distinguish between storm and tsunami deposits. Furthermore, landscape paleoreconstruction permits estimation of sea level and coastline position at the time of displacement, which is important for calculation of forces required for transport.”
4. They were also about a half dozen in-line suggestions for word choice and phrasing, that we will address as we continue to revise.
Many thanks for your time and insight!Citation: https://doi.org/10.5194/egusphere-2025-1913-AC3
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AC3: 'Reply on RC1', Rónadh Cox, 26 Aug 2025
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CC1: 'Comment on egusphere-2025-1913', Javier Lario, 21 Jul 2025
As other comments have noted, this paper offers a valuable description of a standardized approach that can be applied to coastal boulder studies. However, there is a noticeable omission of relevant previous work that the authors are presumably familiar with, given their expertise in the region (Caribbean and Canary Islands), such as Lario et al. (2020) and Galindo et al. (2024).
Lario et al. (2020). An extreme wave event in eastern Yucatán, Mexico: Evidence of a palaeotsunami event during the Mayan times (https://doi.org/10.1111/sed.12662).
Galindo et al. (2024). An extreme wave event in Timanfaya National Park: Possible first geological evidence of the 1755 Lisbon tsunami in Lanzarote, Canary Islands (https://doi.org/10.1002/esp.5953)
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Citation: https://doi.org/10.5194/egusphere-2025-1913-CC1 -
AC1: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
We thank Professor Lario for his kind comments on the quality and value of our manuscript.
We recognise his team's interesting contributions to understanding coastal builder transport, but, as shown in figure 2 of the manuscript, there are hundreds of coastal boulder papers published in the past decade, and it is not possible for us to site every deserving study. Our present bibliography with almost 180 references represents a wide ranging and balanced overview of both foundational and current research on the topic. We are sorry we cannot include every relevant paper.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC1 -
AC2: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
We thank Professor Lario for his kind comments on the quality and value of our manuscript.
We recognise his team's interesting contributions to understanding coastal builder transport, but, as shown in figure 2 of the manuscript, there are hundreds of coastal boulder papers published in the past decade, and it is not possible for us to site every deserving study. Our present bibliography with almost 180 references represents a wide ranging and balanced overview of both foundational and current research on the topic. We are sorry we cannot include every relevant paper.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC2
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AC1: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
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RC2: 'Comment on egusphere-2025-1913', Anonymous Referee #2, 18 Aug 2025
Overall, this manuscript presents a useful and clear contribution to the study of coastal boulder deposits. The rationale and objectives are well-explained, and the emphasis on standardising field methodologies is timely and important. The popularization of the ISROC-DB and the proposed protocols will be valuable for improving data comparability, reproducibility, and applicability across research groups and disciplines.
My main recommendation is to carefully review the manuscript’s punctuation and sentence structure. There are multiple instances where semicolons could be replaced with commas, and in some sentences, punctuation appears to be missing. Addressing these issues will improve readability and clarity without changing the scientific content.
Minor copyediting for grammar and punctuation is suggested throughout the text to ensure the manuscript reads smoothly and professionally. I have attached a PDF with additional minor suggestions for the authors.
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AC4: 'Reply on RC2', Rónadh Cox, 26 Aug 2025
Thank you for your positive and constructive comments on our manuscript. We are grateful for your feedback on the quality of explanation of the rationale objectives, and we appreciate your opinion that the work is timely and important.
Thank you also for the line edits on the PDF. We will go through them point by point and evaluate the grammar and punctuation choices. We agree with you that smooth reading is important and we will make any necessary edits.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC4
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AC4: 'Reply on RC2', Rónadh Cox, 26 Aug 2025
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2025-1913', Giovanni Scardino, 11 Jul 2025
This paper provides a useful description of a standardized approach that can be applied to coastal boulder studies. In particular, it details protocols for defining boulder lithology, assessing dimensional parameters, and evaluating the wave flow required to initiate boulder motion. This paper could serve as a benchmark for scientists who wish to reproduce field surveys on coastal boulders.
I have included only a few comments in the attached PDF file for your consideration during revision. Additionally, I would like to highlight another aspect that could be addressed: the importance of chronological constraints for paleoreconstructing the landscape at the time of boulder displacement. In my opinion, this is a key factor in accurately assessing boulder motion and can help distinguish between storm and tsunami deposits. Furthermore, paleoreconstruction allows for the estimation of sea level and coastline position at the time of displacement—both crucial parameters for numerical modeling.
Many thanks and kind regards.
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AC3: 'Reply on RC1', Rónadh Cox, 26 Aug 2025
Thank you for your thoughtful comments on our manuscript. We have incorporated them into our revised manuscript, as follows:
1. You pointed out that we should provide more specific information in the Abstract about the kinds of field protocols being suggested. We have revised the text at line 52 to read:
“Using standardised and comprehensive data reporting with due attention to precision and reproducibility—including site characteristics, boulder dimensions, complete positional data, tide characteristics, and geodetic and local topographic datum information—will help ensure complete data retrieval in the field.”
2. We have also replaced the phrase “longitudinal monitoring” in the abstract with “long-term monitoring”, in response to your request for greater clarity.
3. You stated both in the PDF and in your reviewer comments that we should include information about chronologic constraints on landscape reconstruction. To that end, we have edited the first paragraph in section 6 (lines 740 et seq.), which now reads as follows:
“Determining emplacement age(s) of coastal boulder deposits, and (for ancient example) establishing chronological constraints on the landscape at the time of boulder displacement are very desirable goals. Such data permit construction of event chronologies, and by comparison with other archives such as wave climate or earthquake records, can help distinguish between storm and tsunami deposits. Furthermore, landscape paleoreconstruction permits estimation of sea level and coastline position at the time of displacement, which is important for calculation of forces required for transport.”
4. They were also about a half dozen in-line suggestions for word choice and phrasing, that we will address as we continue to revise.
Many thanks for your time and insight!Citation: https://doi.org/10.5194/egusphere-2025-1913-AC3
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AC3: 'Reply on RC1', Rónadh Cox, 26 Aug 2025
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CC1: 'Comment on egusphere-2025-1913', Javier Lario, 21 Jul 2025
As other comments have noted, this paper offers a valuable description of a standardized approach that can be applied to coastal boulder studies. However, there is a noticeable omission of relevant previous work that the authors are presumably familiar with, given their expertise in the region (Caribbean and Canary Islands), such as Lario et al. (2020) and Galindo et al. (2024).
Lario et al. (2020). An extreme wave event in eastern Yucatán, Mexico: Evidence of a palaeotsunami event during the Mayan times (https://doi.org/10.1111/sed.12662).
Galindo et al. (2024). An extreme wave event in Timanfaya National Park: Possible first geological evidence of the 1755 Lisbon tsunami in Lanzarote, Canary Islands (https://doi.org/10.1002/esp.5953)
.
Citation: https://doi.org/10.5194/egusphere-2025-1913-CC1 -
AC1: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
We thank Professor Lario for his kind comments on the quality and value of our manuscript.
We recognise his team's interesting contributions to understanding coastal builder transport, but, as shown in figure 2 of the manuscript, there are hundreds of coastal boulder papers published in the past decade, and it is not possible for us to site every deserving study. Our present bibliography with almost 180 references represents a wide ranging and balanced overview of both foundational and current research on the topic. We are sorry we cannot include every relevant paper.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC1 -
AC2: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
We thank Professor Lario for his kind comments on the quality and value of our manuscript.
We recognise his team's interesting contributions to understanding coastal builder transport, but, as shown in figure 2 of the manuscript, there are hundreds of coastal boulder papers published in the past decade, and it is not possible for us to site every deserving study. Our present bibliography with almost 180 references represents a wide ranging and balanced overview of both foundational and current research on the topic. We are sorry we cannot include every relevant paper.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC2
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AC1: 'Reply on CC1', Rónadh Cox, 26 Aug 2025
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RC2: 'Comment on egusphere-2025-1913', Anonymous Referee #2, 18 Aug 2025
Overall, this manuscript presents a useful and clear contribution to the study of coastal boulder deposits. The rationale and objectives are well-explained, and the emphasis on standardising field methodologies is timely and important. The popularization of the ISROC-DB and the proposed protocols will be valuable for improving data comparability, reproducibility, and applicability across research groups and disciplines.
My main recommendation is to carefully review the manuscript’s punctuation and sentence structure. There are multiple instances where semicolons could be replaced with commas, and in some sentences, punctuation appears to be missing. Addressing these issues will improve readability and clarity without changing the scientific content.
Minor copyediting for grammar and punctuation is suggested throughout the text to ensure the manuscript reads smoothly and professionally. I have attached a PDF with additional minor suggestions for the authors.
-
AC4: 'Reply on RC2', Rónadh Cox, 26 Aug 2025
Thank you for your positive and constructive comments on our manuscript. We are grateful for your feedback on the quality of explanation of the rationale objectives, and we appreciate your opinion that the work is timely and important.
Thank you also for the line edits on the PDF. We will go through them point by point and evaluate the grammar and punctuation choices. We agree with you that smooth reading is important and we will make any necessary edits.
Citation: https://doi.org/10.5194/egusphere-2025-1913-AC4
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AC4: 'Reply on RC2', Rónadh Cox, 26 Aug 2025
Peer review completion
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(1453 KB) - Metadata XML
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Supplement
(50 KB) - BibTeX
- EndNote
- Final revised paper
This paper provides a useful description of a standardized approach that can be applied to coastal boulder studies. In particular, it details protocols for defining boulder lithology, assessing dimensional parameters, and evaluating the wave flow required to initiate boulder motion. This paper could serve as a benchmark for scientists who wish to reproduce field surveys on coastal boulders.
I have included only a few comments in the attached PDF file for your consideration during revision. Additionally, I would like to highlight another aspect that could be addressed: the importance of chronological constraints for paleoreconstructing the landscape at the time of boulder displacement. In my opinion, this is a key factor in accurately assessing boulder motion and can help distinguish between storm and tsunami deposits. Furthermore, paleoreconstruction allows for the estimation of sea level and coastline position at the time of displacement—both crucial parameters for numerical modeling.
Many thanks and kind regards.