the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 03 Sep 2026
Luminescence dating of offshore tsunami deposits from the Shetland Islands, United Kingdom
Abstract. With onshore geological evidence of three tsunami events, the Shetland Islands (UK) yield the most-detailed Holocene tsunami record in the North Sea region. Lately, tsunami deposits were also identified in shallow waters offshore the Shetland Islands. These offshore tsunami deposits may carry the potential to further improve our understanding of both local and basin-wide, long-term tsunami hazard. Making use of the offshore record, however, requires establishing robust event chronologies. By using cores collected from two shallow-marine embayments located in the eastern Shetlands (Dury Voe and Colgrave Sound), we present the first chronology for offshore tsunami evidence from this region based on luminescence dating by resolving critical methodological challenges. The offshore cores show four distinct layers that contrast with the background shelf sediments. We find micro X-ray fluorescence mapping to be a rapid and effective method for assessing the geometries and internal architectures of these candidate tsunami deposits, which helps to guide sampling for luminescence dating. Complex radiation fields and time-dependency of environmental dose rates are tackled by implementing representative water contents, site-specific internal potassium contents, modeled dose rates considering the effect of radioactive disequilibria, and stratigraphic heterogeneity on the scale of gamma radiation. We demonstrate how robust luminescence-based chronologies can be achieved through measuring silt- and sand-sized K-feldspars with a pIRIR130 protocol in combination with Bayesian age-depth modeling under these conditions. Our luminescence chronologies indicate sedimentary evidence of the Storegga tsunami at offshore Dury Voe and Colgrave Sound, and additionally of the late-Holocene tsunami at offshore Dury Voe. Overall, these results demonstrate both the great potential of luminescence dating for offshore tsunami deposits and the benefits of the associated chronologies for regional tsunami hazard assessment.
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Status: final response (author comments only)
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RC1: 'Comment on egusphere-2026-3279', Anonymous Referee #1, 06 Oct 2026
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AC1: 'Reply on RC1', Andreas Peffeköver, 28 Oct 2026
Dear Anonymous Referee #1,
We would like to thank you very much for taking the time to carefully review our manuscript and for providing valuable, constructive, and detailed feedback. We would like to explain our plan and strategy for addressing major comments raised in a revised manuscript version:
We acknowledge difficulties with reading comprehension related to extensive references being made to another manuscript, which was in review by the time of initial submission. A preprint of this paper was accessible and included in the reference list. We are glad to inform you, that, in the meantime, the respective paper by An Nahar et al. was published in Marine Geology (https://doi.org/10.1016/j.margeo.2026.107901). The work by An Nahar et al. (2026) is fundamental for our study as it establishes the basin-wide stratigraphies and sedimentary evolution of both of our field sites: Dury Voe and Colgrave Sound/Basta Voe. In order to improve the comprehensibility of our manuscript, we plan to implement summary tables showing the lithological characteristics and depositional interpretations of the stratigraphic units identified in our cores, as well as how they correlate with the basin-wide stratigraphy published by An Nahar et al. (2026), highlighting its relevance for our interpretations and discussions.We also plan to improve the comprehensibility of the discussion chapter by restructuring the first part of the chapter by summarizing the main findings of our study first. We will carefully review and clarify our interpretations and improve the visualization of our data by adjusting some of the figures as suggested. With this, we aim for improving the overall structure of our manuscript, as well as making it more self-contained. Furthermore, specific comments raised will be addressed in a revised manuscript version.
Many thanks and best regards,
Andreas Peffekover & Dominik Brill on behalf of all co-authorsCitation: https://doi.org/10.5194/egusphere-2026-3279-AC1
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AC1: 'Reply on RC1', Andreas Peffeköver, 28 Oct 2026
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RC2: 'Comment on egusphere-2026-3279', Anonymous Referee #2, 19 Oct 2026
This paper presents new luminescence and XRF data for two off-shore cores containing tsunami deposits and relating them to the on shore record found in the Shetlands. As such it is of wide interest. Application of luminescence to marine sediments is complex and the authors acknowledge these and have shown a careful and systematic approach to overcome these additional challenges. I am happy to see it published but before it is the authors should consider the following which I hope they find constructive:-
Major comments
[1] The abstract sets the paper up well to demonstrate the added value of understanding off-shore shallow water tsunami deposits but concludes that work show the potential of luminescence dating of these deposits. Seems like a mismatch to me so some clarity on what the paper aims to actually achieve might be helpful for the reader. The paper finishes with a section on potential for linking on-shore to off-shore which us not supported I feel by what is actually in this paper.
[2] The paper is a frustrating read in that there are so many references to a companion paper which is in review and therefore not available for this review. I think it would be helpful if this paper was either stand-alone or waited until the other paper is published. As the main thrust of the paper is about dating the tsunami sediments a brief visual description and interpretation of the two cores in question could suffice in my opinion.
[3] If the main theme of the paper is the luminescence dating then too much of the data needed to see if this has been applied correctly and well is buried in the supplementary info. As a result things like the modelling of disequilibria through time is not clear in the main text. It seems like sensitivities for various senarios were tested but not how they were evaluated or which was correct. Likewise results seem to show age over-estimations for some samples whereas the dose recovery tests indicate an under estimation should be expected of given to measured – this was not commented on. I would recommend to the authors they consider rowing back on references and text relating to Nussburger et al thereby creating space in the main body of text to explain and showcase the work presented in this paper. Figs S4 and S5 should be in the main paper replacing the summative insets in existing figure
[4] Results are evaluated against “known tsunami events” (L513). This slightly confused me as I thought the paper was sampling unknown age off-shore deposits and dating them. If they are of known age where is the chronology for these cores from? Why is the age depth modelling needed is the ages are known already? Was the fact that some ages are based on very little data - more so when only FMM/MAM used considered when looking are results and excluding results? Following on from this some pIRIR130 ages are excluded from age-depth modelling as too old even though they are within error of the “right” age and even though as per the text the event deposit ages were better than the shelf-deposit ages. This feels like circularity of arguments. Given a different approach is taken for each site this needs better justification I feel to avoid feeling like choosing the answer which meet expectations. Even if this is not the case and works, here if this paper is to help others date off-shore tsunami deposits on unknown age a clear decision making process needs to be outlined – this would be a good take away outcome form this work.
[5] The first part of the discussion is outlining information from Nussberger et al in review and is not discussing the new data presented in this paper.
More minor/specific comments
L37 “several” is often taken to 3-5 – might be better rephrased to thousands and tens of thousands?
L54 reference to a paper under review which can’t be verified within this review.
L67 reference to a paper under review which can’t be verified within this review.
L100 reference to a paper under review which can’t be verified within this review – is this new sea level work needed for this paper or is already published work enough?
L115 reference to a paper under review which can’t be verified within this review – is this needed?
L128 “runup” I think should be two words
L144 reference to a paper under review which can’t be verified within this review – is this needed?
L154 reference to a paper under review which can’t be verified within this review – is this needed?
L163 this sentence assumes a tsunami impact. Might be better to first state the sand and shell lenses were interpreted as tsunamigenic.
L165 Either don’t mention the within deposit 14C ages if they are older or explain why they are older but considered wrong. As it stands I felt this was a little confusing.
L149-160 – not clear why these two areas were selected and why they are the right place to tie off-shore and on-shore records together.
L165-174 reference to a paper under review which can’t be verified within this review – is this needed – could just say where cores came from and describe them?
Fig 1c make Dury Voel able more prominent so easier to see and tie with text. Same for Fig 1d
L188 reference to a paper under review which can’t be verified within this review – is this needed? Do readers of this paper need to know there were 31 cores if only 2 are presented?
L190 – why only two cores and why these cores?
L199 Maybe rephrase what is meant by “background” sediments. I am taking this to mean sediments used for background dose-rate measurements. Also please specify what “directly above and below” means. I would like assurance that the sampled sediment units above and below extended at least 70cm from the dated sediment as the gamma dose rate to the dated sediment will have made some contribution over this distance. Samples taken need to be representative of this or further samples should have been considered if it varied.
L202-214 uXRF is stated as being used to locate where to sample but this data is never given. Fig 3 does give some ratio results on certain elements but not clear why these are paired and different ones shown for different parts of the same core and between cores. Consider giving a table of the actual results and also an interpretation of each unit in terms of terrestrial/marine, biogenic carbonate etc.
Related to this there is a general lack of description of the cores, what was sampled and a depositional interpretation of it. This is important as it implies that some sediments above or below the tsunami sediment were of terrestrial origin and so unsupported U issues with dose rate would not be applicable within the luminescence dating method. Finally in the results there are a description but no methods were given for this and it would have been better to have a brief sed/unit description as part of sampling section to show why and where sampled. This would also avoid reliance on an in review inaccessible paper.
Fig 2 fails to give sedimentary interpretations for the different units or a key for the fills used. What is red fill?
Fig 3 why different ratios for different parts of the core? Where is the tsunami unit? Annotate a,c,e with interpretations?
L228 replace “patches” with “diameter”
L247 A careful approach to determining which temperature of pIRIR was adopted but none of the data is given so a reader cannot validate whether the authors chose wisely or not. This info is given in the results section l454-471 but would be better given I feel here to justify the approach taken for measuring the samples for dating.
L255 I am unconvinced that 10 SG De values is sufficient to publish an age from. A number of aliquots/grains measured is not given in Table 2 ( I would recommend adding) I can’t see how reliable an age based on 10 grains is compared to others around it.
L259 What constitutes “larger overdispersion values” give the threshold used in this study and its justification.
L263 the flexible model approach based on De distribution looks sensible but which of the FMM components is used for age calculation and why?
L285 see Bateman et al 2025 Quat. Geochron. who tried to model water content change through time and showed how this affected ages calculated.
L289 Water saturation experiment samples appear to be on sediment very different to that of the tsunami sediment itself so not sure how representative they are for beta dose rate of what was dated.
L323 “in dependence”? rephrase?
L326 fading correction is in wrong place as this is a dose rate section – also dealt with later in text
L328-335 disequilibria important if you are dating marine sediments. Looks like adopted a range or senarios but details of how this done and which was adopted where are unclear. -I would like to see more details. It is unclear from the subsequent results section how this was resolved to create DRmod. As per table 1 caption this appears only to consider change sin water content and internal K but not changes in disequilibrium through time. Mauz as written about this in the context of changing cementation through time and Armitage has published about modelling this for marine sediments.
L431-439 These section did not enlighten me enough to understand how the disequibria which had been identified was dealt with in terms of time dependant change.
Fig 3 separate out the DE distributions for the different measurements as its not possible to see them. Also consider abanico plots. The distributions for all samples should be made available in main text and/or supplementary info.
L483 did you consider the lower scatter for FG measurements reflect averaging effects on 000s of grains comparted to single grains at the coarse grain level?
L571-598 section on potential for linking on-shore to off-shore which is not supported I feel by what is actually in this paper. The XRF results are not in the discussion section but would be better placed there.
Supplementary info
As a great multi-layer approach was taken for the external gamma dose can we have the details of the doses from adjacent sediments and an indication of how important this step was in correcting the dose rate
Citation: https://doi.org/10.5194/egusphere-2026-3279-RC2 -
AC2: 'Reply on RC2', Andreas Peffeköver, 28 Oct 2026
Dear Anonymous Referee #2,
We would like to thank you very much for taking the time to carefully review our manuscript and for providing valuable, constructive, and detailed feedback. We would like to explain our plan and strategy for addressing major comments raised in a revised manuscript version:
[1] We will make sure to emphasize the objectives of our study in the abstract more clearly and we will carefully review our implications about coupling on- and offshore tsunami deposits on the Shetland Islands.
[2] We acknowledge difficulties with reading comprehension related to extensive references being made to another manuscript, which was in review by the time of initial submission. A preprint of this paper was accessible and included in the reference list. We are glad to inform you, that, in the meantime, the respective paper by An Nahar et al. was published in Marine Geology (https://doi.org/10.1016/j.margeo.2026.107901). The work by An Nahar et al. (2026) is fundamental for our study as it establishes the basin-wide stratigraphies and sedimentary evolution of both of our field sites: Dury Voe and Colgrave Sound/Basta Voe. In order to improve the comprehensibility of our manuscript, we plan to implement summary tables showing the lithological characteristics and depositional interpretations of the stratigraphic units identified in our cores, as well as how they correlate with the basin-wide stratigraphy published by An Nahar et al. (2026), highlighting its relevance for our interpretations and discussions.
[3] We will consider moving some information from the supplementary material to the actual manuscript. Since we detected radioactive disequilibria in the U-series decay chain, we decided to calculate dose rates for three different scenarios: (1) a minimum dose rate (DRmin) based on 238U concentrations derived from gamma-ray spectrometry; (2) a maximum dose rate (DRmax) based on 226Ra concentrations measured by gamma-ray spectrometry; (3) a modeled dose rate (DRmod) based on changing U activities over time. The alpha-spectrometry measurements for selected samples (Table S5) demonstrate that disequilibria in the cores are installed at 238U’s daughter nuclide 230Th, which is associated with the presence of biogenic carbonates. We found that using DRmod (i.e., accounting for radioactive disequilibria) serves as the best representative for dating purposes. However, sensitivity tests comparing DRmod to the endmembers of DRmin and DRmax revealed deviations that were within the systematic error range of luminescence dating.
[4] In the absence of independent age control, we evaluate the accuracy of our luminescence chronologies by comparing them to the ages of “known tsunami events”. By “known tsunami events”, we refer to the Holocene tsunami events that have occurred in the North Sea basin (Chapter 2.2.1) and which are evident on the Shetland Islands (Chapter 2.2.2). Thus, the ages of candidate event deposits identified in the cores used in our study were indeed unknown until we dated them by means of luminescence. By accounting for stratigraphic succession and hiatuses, as well as by discriminating between instantaneous and continuous sedimentation, applying a Bayesian age-depth model helped to further improve the accuracy of our luminescence chronologies (L 678-680). We decided to exclude pIRIR130 ages of the Colgrave Sound samples from its age-depth model because they seem to overestimate the true burial age (i.e., the ages of “known tsunami events” (Fig. 5b)). Our decision is backed by the observed luminescence properties of the pIRIR-signal for Colgrave Sound: due to slow signal resetting, illumination time had to be increased from 300 s to 500 s, which indicates that K-feldspar originating from Colgrave Sound may exhibit poorer signal resetting than K-feldspar from Dury Voe. We will better outline this decision-making process in our revised manuscript version.
[5] We plan to improve the comprehensibility of the first part of the discussion chapter by summarizing the main findings of our study first and then correlate them to the basin-wide stratigraphy published by An Nahar et al. (2026).
Many thanks and best regards,
Andreas Peffekover & Dominik Brill on behalf of all co-authorsCitation: https://doi.org/10.5194/egusphere-2026-3279-AC2
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AC2: 'Reply on RC2', Andreas Peffeköver, 28 Oct 2026
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CC1: 'Comment on egusphere-2026-3279', Barbara Mauz, 28 Oct 2026
Identifying and dating a Holocene catastrophic event on the shelf of the northeast Atlantic is demanding: discriminating background sediment from event deposits while not knowing the exact position of the sea level at the time of the event and dating high-energy offshore deposits - a challenge indeed that attracts my attention.
mXRF mapping was used to identify the event deposits. This method required sub-sectioning the inferred deposits and this procedure appears to have been guided by visual inspection of the surface of the split core following core logging. However, the data shown in Fig. 2 do not allow to understand why the authors selected horizons at core depths of ~50 cm, 225 cm, and ~15 cm, ~110 cm as “candidates”: the key for texture is missing, the photos are blurred and the caption is incomplete. The illustration in Fig. 2 suggests that the candidate deposits are 10-20 cm thick – did the authors expect this thickness bearing in mind physical properties of the Storegga landslide? If the sea level was between 34 m and 27 m lower than today and ca 8 ka, the seafloor at Dury Voe was somewhere in the inter-subtidal, hence affected by the minimum tsunami run-up as indicated by Dawson et al 2020. Colgrave Sound must have been on the inner shelf and, eventually, below the wave base. Is the inner shelf deposit as sandy as the run-up deposit in the formally glaciated area? Why is a beach environment assumed? What do we know about the tidal range and the tidal prism at the time of the event given the larger emerged (terrestrial) area at the time ?
A U-chain disequilibrium is assumed because “Th-230 installs disequilibria in the U decay chain” (header of table 1) and in line 620ff the text says: “we assume the presence of calcareous sediments at our field sites to create disequilibria...”. In Fig 4 the apparent disequilibrium is shown by plotting Ra/U ratio against core depth - which U-element was used and how were U and Ra-226 determined? The figure caption isn’t helpful here.
I do not find ‘calcareous sediment’ in the facies description (sec 4.1.1) where, instead, sand and silt with variable content of shell fragments is indicated. It seems that the shell fragments are mistaken as ‘carbonates’. How do shell fragments create a disequilibrium? Surely, U-activity ratios vary greatly in surface waters and this variability is even greater for Ra-226 (Osmond and Ivanovich, 1992). It does not necessarily lead to a secular disequilibrium that would affect the dose rate. The disequilibrium is therefore not observed but inferred. The U/Th ratios of the data listed in Table 2 do not suggest elemental disturbance. In fact, in lines 630ff the text says “both parameters [water and internal K content] are found to be more significant for the corresponding dose rates than observed radioactive disequilibria” why discussing disequilibrium then? I feel the manuscript lacks in focus and structure. Citing an inaccessible manuscript (under review) is clearly not helpful.
Citation: https://doi.org/10.5194/egusphere-2026-3279-CC1
Data sets
Luminescence dating of offshore tsunami deposits from the Shetland Islands, United Kingdom Andreas Peffeköver, Max Engel, Stephan Opitz, Anja Zander, Maarten Van Daele, Pedro J. M. Costa, Sue Dawson, Rikza N. F. An Nahar, Juliane Scheder, Vanessa M. A. Heyvaert, Marc De Batist, and Dominik Brill https://doi.org/10.5281/zenodo.21363495
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The manuscript presents new data acquired from two sediment cores collected in two different shallow marine embayments offshore the South Shetland Islands. The study aims to investigate tsunami deposits and apply luminescence dating techniques to constrain the timing of the identified events.
Given my expertise, I focused particularly on the geological aspects and the interpretation of the sediment samples. Overall, I found the manuscript very interesting and potentially worthy of publication after addressing the comments below.
The manuscript is of high quality and represents a valuable contribution to the scientific community working on tsunamis and other high-energy depositional events, which are often challenging to date accurately. The study is well written, logically organized, and certainly merits publication after several revisions have been made to clarify some aspects of the interpretations, improve the presentation of the data, and provide stronger support for the conclusions drawn.
I found some difficulty in following the core descriptions, as outlined in the more detailed comments below. In addition, a few inconsistencies in the interpretation of the sedimentary units should be carefully reconsidered.
Although the study primarily focuses on the dating of the events, it makes extensive reference to another manuscript currently under review, in which cores collected from approximately the same locations were used to reconstruct sedimentary facies and the geological processes responsible for the deposition of the event layers. While this demonstrates that the dataset is robust and that the interpretations are supported by multiple lines of evidence, it also makes the manuscript difficult to follow, as the reader is frequently required to consult a second unpublished study in order to understand the basis of many of the interpretations presented here.
I therefore encourage the authors to include within the present manuscript the key information required for the discussion, either in the form of summary tables, figures, or concise descriptions in the text. Without these direct references, readers are forced to consult both manuscripts in parallel to understand how the interpretations were developed.
Specific comments
The introduction is well structured and provides a clear overview of the current state of knowledge and the associated uncertainties. I recommend verifying that all acronyms are properly defined and consistently reported throughout the text, figures, and figure captions.
The source and trigger of the late-Holocene tsunami have been interpreted as local. However, the related deposits have been identified over a remarkably wide geographical area onshore, as shown in Figure 1b. This point deserves further discussion.
Lines 185-190: It would be useful to summarize the main morphological, oceanographic, and geological characteristics that guided the site selection, as these factors are likely relevant for interpreting the results and also differences between the described cores and other cores in the area.
Line 192: Please explain why only these two cores were selected for this study. What was the rationale behind their selection?
Lines 203-204: Please specify which environmental conditions are being referred to and explain how these conditions are reflected in the chosen geochemical proxies.
Figure 1: Please indicate the source of panels c and d. Adding inset boxes highlighting the study areas would facilitate interpretation. In panel 1c and 1d it would be useful to see all the collected cores including those described in the paper by An Nahar et al (under review).
Figure 2: I am not sure what the red color assigned to the two coarse-grained units in the interpretative log represents. The meaning of the symbols used in the log is not explained either in the legend or in the figure caption. At present, understanding these units requires consulting the manuscript by An Nahar et al. (under review). Was grain-size analysis performed? Or does the grain-size information derive solely from visual core descriptions?
Figure 3: I am somewhat confused because the three event deposits are described using different sets of proxies. It would be more useful to consistently use the same parameters for all events, allowing similarities and differences among them to be more easily assessed.
For example, DV1 is described using Na/Mn, S/Mn, Br/Fe, and Na/Ti, but no information is provided regarding marine indicators such as Ca or Sr.
Figure 3e: The top of BV2 appears to be located at approximately 107 cm rather than extending upward as shown. What does the sharp transition at 107 cm depth represent?
Why is BV1 not included in Figure 3?
Is the very sharp upper boundary of DV1 real, or could it be an artifact of the XRF image? In the text (line 372), the upper boundary is described as gradual. Therefore, I am wondering whether the sharp boundary displayed in Figure 3a accurately reflects the sedimentary structure.
Line 362: Please verify the depths of the upper and lower boundaries of this unit (DV2). The depths reported in the text do not appear to match those shown in Figure 2. Based on the core photograph, the event seems to be located between 221 and 231 cm, as illustrated in Figure 2a, whereas the text and Figure 3c suggest a more restricted interval of 221-228 cm. Please clarify these discrepancies and explain why the XRF data do not show significant differences between the event deposit and the surrounding background sediments especially in the lowermost part of the event.
Results and Interpretation
Line 354 - The cores are described as consisting of different "facies" based primarily on texture and shell-fragment content. I suggest replacing the term facies with sedimentary units when referring to the subdivisions identified in the cores. The term “facies” generally implies a depositional and genetic interpretation, whereas sedimentary units is more appropriate for a strictly descriptive classification based on observed core characteristics.
In the introductory paragraph (lines 355-360), the succession of depositional environments is introduced based on the work of An Nahar et al. (under review). To allow readers of this manuscript to follow the interpretative workflow without consulting the companion paper, I recommend first describing the sedimentary units in purely observational terms and only subsequently discussing their depositional significance and environmental interpretation based on results from An Nahar (under review). This would make the manuscript more self-contained and easier to follow.
Lines 370-379 (Event DV1): Based on the core log (Fig2a), the event appears to be subdivided into two distinct sub-units: a lower red-colored interval and an upper interval characterized by finer-grained sediments. This subdivision is neither described nor discussed in the text. What do these two sub-units represent? Do they correspond to two depositional phases related to the same tsunami propagation, or are they interpreted as separate events? Why is the lower sub-unit highlighted in red?
Figure 2b: Why is BV2 colored in red? Does the upward fining trend reported in the core log (105 cm) have any interpretative significance? Could it indicate a subdivision into two sub-units (102-105 cm and 105-117 cm), potentially reflecting more complex depositional processes during tsunami propagation? Furthermore, why do the XRF data cover only the lower portion of the unit? The upper boundary is not included in Figure 3e.
Lines 385-386: The XRF data do not include the upper boundary of the deposit; therefore, this statement is not fully supported. The upper boundary appears to be located at approximately 102 cm depth, whereas the XRF interval extends only across approximately 104-120 cm. Consequently, the luminescence sample BAVO4, described as representing background sediment above the event deposit, actually appears to be located within the event layer itself, as clearly imaged in Figure 3e.
I note that the thickness of the luminescence samples varies between approximately 2 cm and 4 cm. I may have overlooked the explanation in the Methods section, but it would be useful to explain why different sample thicknesses were used and which criteria guided the choice of sampling interval. Such information may be of interest to future applications of the method.
If possible, I would also encourage the authors to include XRF data for BV1, or alternatively explain why these data are not necessary.
Discussion - Before discussing correlations with the cores described by An Nahar et al. (under review), it would be helpful to first summarize the main findings of the present study. Once the original results have been clearly synthesized, they can then be discussed within the broader stratigraphic and regional framework.
The beginning of the Discussion is particularly difficult to follow because it immediately introduces abbreviations for seismic-stratigraphic and sedimentary units derived from other studies. I recommend simplifying this section and making it more accessible to readers unfamiliar with the accompanying manuscript.
Rather than referring extensively to the manuscript under review, it would be beneficial to include a representative sub-bottom profile in the present paper and describe the acoustic characteristics of the event deposits directly from the geophysical data.
Lines 547-549: No Ca or Sr elemental maps are shown in Figure 3a. Therefore, it is currently not possible to verify the following statement: µXRF mapping of DV1 reveals reversed compositional patterns compared to DV2, because here, the event deposit shows as a terrestrial-dominated unit interbedded in marine background sedimentation.
Line 549: The two event deposits are described as being interbedded within two different facies. However, could the observed differences instead reflect changes in sediment source? How can these possibilities be discriminated? Is the interpretation based on the assumption that the event sediment originated from remobilization of pre-existing seafloor material? If the sediment source is external to the coring site, alternative explanations should also be considered.
Line 559: The event is also enriched in Si. Therefore, a mixed sediment source cannot be ruled out. Please explain why a predominantly marine origin is favored. Is Si considered diagnostic of a marine source in this context?
Line 568: Since the origin of BV1 remains uncertain, it would be particularly valuable to compare its XRF signature with those of the other event deposits. Such data could help distinguish tsunami deposits from storm-related deposits. The absence of XRF information for BV1 currently limits this type of analysis.
Finally, grain size appears to be the primary criterion used to identify event deposits in the studied cores. Given its importance, I wonder why detailed grain-size analyses were not performed. High-resolution granulometric measurements might provide valuable additional information and could potentially reveal more subtle grain-size changes associated with other tsunami events that are not readily identifiable from visual core descriptions alone.
Overall, this is a very interesting and potentially impactful contribution. However, the manuscript would benefit substantially from being made more self-contained and from presenting the observational evidence supporting the interpretations more directly within the paper. I hope to see it published soon.