the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 01 Sep 2023
An integrated tsunami inundation and risk analysis at the Makran Coast, Pakistan
Abstract. The coastal cities and areas of Gwadar and Pasni in Pakistan, being highly vulnerable to tsunamis, are investigated for inundation and risk analysis. For modelling, both dynamic and static approaches are used for better understanding and for their comparative analysis. The tsunami wave potential in the Arabian Sea is estimated by compiling and assessing the palaeo-morphodynamics of tsunamite record discovered so far along its coastlines. The dynamic model is calibrated and validated with the inundation limits of the 1945 tsunami in the Pasni area. Further, for risk estimation, three different wave scenarios (7 m, 10 m, and 15 m) are projected on Pasni and Gwadar. Results show that both cities are highly vulnerable to wave heights ≥7 m and wave lengths ≥ 15 km. The 15 m scenario would be almost a complete disaster for both cities and adjoining towns. Results of simulation and comparative analysis also show that due to coastal orientation and morphology, the reflection, integration, and amplification phenomena have a devastating effect on the region, and their intensity increases with the increasing size of the approaching waveform. It variably but significantly affects the inundation extents and depths. At the end, based on the simulated results, the utility of the installed early warning system is assessed.
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RC1: 'Comment on nhess-2023-148', Anonymous Referee #1, 19 Dec 2023
NHESS - COMMENT
- The authors need to justify the choice of the maximum magnitude of the earthquake. What are the seismic hazard assessment studies used? Earthquake parameters for the 9.5 earthquake should better justified or quoted
Why 9.5 and not other?
Other authors suggest smaller maximum magnitudes from MSZ https://geoscienceletters.springeropen.com/articles/10.1186/s40562-018-0129-4
- The comments on the efectivenness of the IOTWS should be reviewed and improved. Authors need to define Reaction time (see line 376) “Due to its proximity to MSZ, Makran Coast is unable to fully benefit from the Indian Ocean Tsunami Warning and Mitigation System (IOTWS), a far-field early warning system established in the Arabian Sea. This method is beneficial for the south-western Indian coast, including Mumbai city, since far-field warning mechanism can operate for it.”
The authors need to better justify this sentence. Did the authors look at the last events? How much time was needed between the occurrence of the earthquake and the issue of the first message? https://link.springer.com/content/pdf/10.1007/s12594-021-1910-0.pdf
- Despite the need to vertical evacuation spots these are useless if populations do not know the natural signs of a tsunami. The authors should comment on this topic
- The paper shows an interesting study on tsunami vulnerability of the coast of Makran.
- Concerning the table of interviewed people. I doubt very much of the report of a witness aged 4-5 years to remember the tsunami. Most likely he repeats what he is told by others…..
- In the table correct “Tasunmi water came to Daragah” to “Tsunami water came to Daragah”
- However, risk is not accessed in the paper.
- References that need to be included in the text
Citation: https://doi.org/10.5194/nhess-2023-148-RC1 -
AC1: 'Reply on RC1', Rashid Haider, 09 Jan 2024
Dear Anonymous Referee #1,
We thank you for your valuable time, effort, and useful comments on our manuscript. Each comment and suggestion is addressed. detailed below, please.
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NHESS: COMMENT
1. The authors need to justify their choice of the maximum magnitude of the earthquake. What are the seismic hazard assessment studies used? The earthquake parameters for the 9.5 earthquake should be better justified or quoted. Why 9.5 and not others?
Other authors suggest smaller maximum magnitudes from MSZ: https://geoscienceletters.springeropen.com/articles/10.1186/s40562-018-0129-4
Deterministically, the researchers have estimated the maximum earthquake potential using two different proxies and then further modelled various numerical scenarios for hazard and risk studies. We went back to this proxy, first by estimating the maximum tsunami height potential using the tsunamites proxy, followed by modelling the various earthquakes to test the waves consistent with the extreme morpho-dynamics exhibited by the tsunamites (Sur-Fin, Oman Coast). Therefore, our study gives an indirect approximation of the maximum earthquake potential. We explained this in detail in Section 3.1, Establishing the tsunami wave potential in the Arabian Sea.
We further explain these proxies in comparison to our computational model. Discussed below briefly.
FIRST PROXY (explained in Section 2.1: Tectonic Settings and Assimilation):
The first proxy involves thermal modelling of the subduction. The high seismic velocities due to the lack of soft sediments along the fault plane result in the brittle nature of decollement. Further, it shows that its potential is comparable to the December 2004 Sumatra rupture and could trigger up to a Mw 9.2 earthquake (Smith et al. 2012). Estimates from another thermal modelling study suggest a potential of Mw 8.65 ± 0.26 in western Makran (Iran) and 8.75 ± 0.26 in eastern Makran, Pakistan (Khaledzadeh and Ghods 2022).
SECOND PROXY (added in Section 2.1, Tectonic Settings and Assemicity):
El-Hussain et al. (2017, 2018) (Al-Habsi et al. 2022) computed a maximum Mw of 8.8 based on the available seismic information, which is not explained further by them. However, in their publication (El-Hussain et al. 2016), they inversely calculated the maximum moment of an earthquake using the geodetic slip rate to calculate the rate of seismic moment. It is basically based on a simplified relationship (Brune 1968; Hanks and Kanamori 1979) between the rate of seismic moment and geodetic slip rates. We may call this the second proxy.
THIRD PROXY (we used reverse engineering)
We used the tsunami size proxy to estimate the tsunami size in this paper. Then find the earthquake capable of generating that particular tsunami dynamics through Okada (1985) fault parameters. We compiled all the tsunamis discovered so far along the shorelines bordering the Arabian Sea (Table S1 supplements). We took the tsunamis exhibiting worse morphodynamics at the beach-cliff situated between Fins and Tiwi, Oman, as a case study to estimate the maximum wave potential. Further, we modelled the tsunami using Okada (1985) earthquake parameters and tested various cases to find the one capable of producing the required flow velocity to dislodge and drag the boulder tsunamites to their current position against gravity. In our case, the parameters and moment of magnitude (Mw 9.5) are given in Section 3.1. Further, the earthquake size is capable of triggering such a tsunami. We cannot rule out the other tsunami sources (landslides, celestial impacts, submarine volcanism, etc.). However, the findings of the authors of these tsunamis suggest an earthquake source based on tsunami size along with a long-axis rose plot (paleocurrent direction) pointing MSZ (Hoffmann et al. 2013).
Regarding hazard estimation, it is pertinent to mention the probabilistic approach as well. In the probabilistic approach, the problem always involves the maximum magnitude assumption (Behrens et al., 2021; Hoechner, Babeyko, and Zamora, 2016; Yoshihiro and Takaaki, 2004; Grünthal et al., 2018). This factor severely affects the tsunami hazard assessment if the historical record is not available or is feeble, as in the case of MSZ.
2. The comments on the effectiveness of the IOTWS should be reviewed and improved. Authors need to define Reaction time (see line 376) “Due to its proximity to MSZ, Makran Coast is unable to fully benefit from the Indian Ocean Tsunami Warning and Mitigation System (IOTWS), a far-field early warning system established in the Arabian Sea. This method is beneficial for the south-western Indian coast, including Mumbai city, since far-field warning mechanism can operate for it.”
The authors need to better justify this sentence. Did the authors look at the last events? How much time was needed between the occurrence of the earthquake and the issue of the first message? https://link.springer.com/content/pdf/10.1007/s12594-021-1910-0.pdf
As advised, the effectiveness of the Indian Ocean Tsunami Early Warning Centre (IOTWS) is reviewed and rewritten. It’s both aspects (near-field and far-field) are discussed for Makran Coast. Further, compared the near-far field tsunami arrival timings in the study area with timing of the 1st warning and the 2nd tsunami warning issuance. The reaction time is defined. In case of a near-field tsunami at the MSZ, we explained further that why the study area would miss the 2nd warning (tsunami confirmation) due to its small-time window owing to closeness/proximity to the tsunami source.
In this regard, one near-field and two far-field case studies are discussed; 17 September 2013 Makran tsunami (near-field case), 17 July 2006 Java tsunami (far-field case) and 25 October 2010, Mw 7.7, Mentawai, Indonesia (far-field case). The timeline of events for each case is also presented in a table (added as a supplement to Table S2).
3. Despite the need for vertical evacuation spots, these are useless if populations do not know the natural signs of a tsunami. The authors should comment on this topic
"The community’s alertness and watchfulness are very important; the most common natural tsunami signs are considered the receding water after an earthquake and a strong and unusual roar sound. Awareness coupled with training, route evacuation, and the ability to react during such disasters is also important.”.
4. The paper shows an interesting study on the tsunami vulnerability of the coast of Makran.
Comment on numbers 2 and 3 and address them together.
We renamed our title word "risk" to "vulnerability.”. The whole manuscript is updated accordingly.
5. Concerning the table of interviewed people,. I doubt very much of the report of a witness aged 4-5 years to remember the tsunami. Most likely, he repeats what he is told by others.
We added the following lines as a footnote under the table.
“Witness aged 4-5 years to remember the tsunami event is doubtful. Most likely, she repeats what she is told by others.”
6. In the table correct “Tasunmi water came to Daragah” to “Tsunami water came to Daragah”
Corrected the spellings (Tsunami)
7. However, risk is not accessed in the paper.
Comment on numbers 2 and 3 and address them together.
We renamed our title word "risk" to "vulnerability.”. The whole manuscript is updated accordingly.
8. References that need to be included in the text
The new references are added in the body and in the bibliography.
Citation: https://doi.org/10.5194/nhess-2023-148-AC1
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RC2: 'Comment on nhess-2023-148', Anonymous Referee #2, 05 Mar 2024
General comments
The paper by Haider and co-authors presents an interesting investigation of some tsunami events along the Makran coast (Pakistan), quantifying their impact on the coastal cities of Gwadar and Pasni in terms of hydrodynamic quantities (flow depth, drag force) and ensuing from these the damages on the infrastructures.
Though representing an important contribution to the hazard assessment of the area, this work presents many weak points that need to be addressed before publication.
They are reported in detail in the “Specific comments” section and need detailed accounting, but in general they can be resumed as follows:
- This application doesn’t sound like a comprehensive risk analysis, while it could be more considered as an enhanced vulnerability assessment, with some elements of risk (percentage of damages on buildings).
- Descriptions are too approximate, leaving too many uncertainties to the reader who isn’t an expert on the area or of the topic, and taking too much for granted. There are many references to toponyms that are not reported in the maps; some concepts are anticipated before description (e.g.: the reference to static and dynamic modelling in the abstract; citing reflection phenomena in Pasni-7m scenario while they are observed only in the following results); the computing techniques and the scenario selection and definition (see point below) are described too superficially. This makes the reading difficult and the whole reasoning difficult to follow.
- The selected scenarios are questionable: the assumption of 7m, 10m and 15m cases should be justified better. Which sources are used to produce them? Only 15m scenario is briefly accounted for. Is it possible to associate each earthquake/tsunami scenario with a return period, for example, or at least justify them in terms of past events?
- Is it correct to use 1945 pieces of evidence as a proxy for simulations that adopt present morphology, especially for roughness coefficients governing inland flooding? Doesn’t this affect the simulations?
Apart from these points, the paper would benefit from more rigour in the description of the techniques adopted and the assumptions made for modelling, considering that not all the readers will be experts in tsunami science or know exactly the toponyms of the area.
In my opinion, the paper can be accepted for publication only after major revisions.
Specific comments
Abstract
Line 12: citing “dynamic and static approaches” before describing them can be misleading, I would change the sentence.
Line 13: not all readers could have in mind the local geography: where is located the Arabian Sea with respect to the investigation site?
Line 20: after the point, it is unclear what “It” refers to.
Introduction
Lines 43-45: the two sentences are very confusing, it is hard to understand their meaning, rephrase them.
Physio-geographical setting and potential tsunamis triggers
Is paragraph 2.2 necessary? Of course, the source type is interesting and deserves attention, but in the paper it isn’t treated nor cited anymore.
Methods
Line 108: magnitude 9.5 is extreme, how can the authors justify it? In the previous section, they stated that the maximum expected Mw was 9.2, here they use 9.5. Why?
It seems from the text that the 15m wave scenario is generated by the Mw=9.5 source: what about the other scenarios (7m and 10m)? Did the author obtain them through other seismic sources in the MSZ, presumably smaller?
Line 124-125: in the static approach, the wave height at the coast is taken equal for each point of the shoreline. Is it a request of the methodology? The simulations for sure provide a distribution of maximum tsunami amplitude on the coast: why can’t this be used?
Results and interpretations
Line 168: the runup usually refers to the maximum elevation reached by the water flooding, so “runup height” doesn’t sound correct.
Line 168: according to Fig. 2A, neither Wadsar nor Parhag are reached by the water.
Line 170: the figure does not report the position of Pasni, that can be inferred from Fig. 1. Placing a label with position of the town can facilitate the reader.
Lines 172-173: reflection does not occur in this scenario, and commenting on it here sounds incomprehensible.
Lines 178-179: the cliffs NE of Pasni are not visible in the figure, so they should be indicated.
Lines 179-180: Fig 3B, flow depth graph, doesn’t seem to show two waveforms.
Line 216: where is Gwadar on the map?
Line 233: again, Gwadar-hammer-head toponym is not reported in the figure.
Line 290: what does damage probability mean? The methodology should be explained a bit, at least. Moreover, in the picture, Main Bazar seems affected by a probability close to 0, not certainly 0.3.
Discussion and conclusions
Line 326: what “hydrodynamics of the period” is referred to? Is hydrodynamics changing with time? Rephrase or explain better.
Line 334: tsunamis are usually a sequence of oscillations, where sometimes the second or third peaks are higher than the first. Is reflection the only possibility? Do the reports describe waves coming from different directions, a fact that would confirm the reflection pattern?
Line 362: for surface roughness, the authors used the present conditions: are they similar to 1945 ones? Using the present conditions to reconstruct a past event can produce excessive waves dampening, affecting the simulations and the source selection. In 1945 probably the “roughness” was smaller, and maybe a smaller tsunami in sufficient to produce the observed effects. Please discuss this.
Lines 380-381: apart from vertical structures and sirens, also panels for evacuation routes and, most of all, education of the population is basic.
Figures and Tables
Figure 1: panel A) The symbols used for landslide location are incomprehensible and unrecognisable. Landslide sources are briefly discussed but not used in the simulations, please consider also discarding them. The label Arabian Sea should be moved here from panel B. Panel B) The black line, marking the inundation limit, is not uniform but changes thickness: why?
Table 2: why Table 2? Where is Table 1?
Figures 2, 3, 4:
- the toponyms are poorly readable on the map. Maybe the authors should consider putting them into a separate box with the corresponding numbers, leaving only these on the map.
- For a better comparison between the two models, the maps should cover the same domain: as it is now, it isn't easy to assess the differences between the two approaches.
- The graphs would benefit from adding some ticks on the horizontal axis, to see also fractions of hours.
Figures 5, 6, 7:
- Same comments about the map domain and the graph ticks previously reported for Figures 2, 3, 4.
Minor issues and typos
Line 31: after “investigated” it is better to put “:”
Line 34: “(Mw 7.7)” seems to refer to the tsunami magnitude. It would be better to add “associated with an earthquake with magnitude” before.
Line 40: remove “;” after “studies”.
Line 55: add “that” after “shows”.
Line 90: “closer to 100 to 675 Mt/year” what does this mean?
Line 154: “providing” instead of “comparing”?
Line 159: “Hydrodynamic”
Line 161: “CD”, justify the assumed value of 0.99 (1).
Line 169: remove “town” after “Wadsar”.
Line 246: 10 m scenario instead of 15?
Line 272: “weak” instead of “weekly”.
Line 325: “These have to be performed” instead of “It is to be performed”.
Line 356: “smaller” instead of “larger”?
Lines 359-360: “Landslide tsunami have USUALLY very short wavelengths…”; add a reference at the end of the sentence.
Table 2: In the brief description of the interviewee Qadir Baksh maybe it’s “tsunami”, not “Tasunmi”
Table 3: is 5 sin sin s0 correct in the Headloss formula? Remove the minus signs also from the equation below.
Figures 4, 5, 6: “New Town” instead of “New Twon”.
Citation: https://doi.org/10.5194/nhess-2023-148-RC2 -
AC2: 'Reply on RC2', Rashid Haider, 11 Mar 2024
Dear Anonymous Referee #2,
We thank you for your valuable time, effort, and useful comments on our manuscript. Each comment and suggestion are addressed. detailed below, please.
===============================================================================================================================
COMMENTS and REPLIES
GENERAL COMMENTS
- This application doesn’t sound like a comprehensive risk analysis, while it could be more considered as an enhanced vulnerability assessment, with some elements of risk (percentage of damages on buildings).
We recognize the importance of refining our focus, and as a result, we have decided to update our title by replacing the term "risk" with "vulnerability." Subsequently, the entire manuscript has been revised to reflect this modification.
- Descriptions are too approximate, leaving too many uncertainties to the reader who isn’t an expert on the area or of the topic, and taking too much for granted. There are many references to toponyms that are not reported in the maps; some concepts are anticipated before description (e.g.: the reference to static and dynamic modelling in the abstract; citing reflection phenomena in Pasni-7m scenario while they are observed only in the following results); the computing techniques and the scenario selection and definition (see point below) are described too superficially. This makes the reading difficult and the whole reasoning difficult to follow.
We will revise the manuscript and add missing sections and explanations where required in the to offer more comprehensive explanations, ensuring that readers can better understand our methodology and reasoning. Additionally, we will ensure that all references to geographic locations (toponyms) are clearly depicted on the maps.
- The selected scenarios are questionable: the assumption of 7m, 10m and 15m cases should be justified better. Which sources are used to produce them? Only 15m scenario is briefly accounted for. Is it possible to associate each earthquake/tsunami scenario with a return period, for example, or at least justify them in terms of past events?
- We will provide a comprehensive overview of each scenario’s choice and the source utilized in the updated manuscript.
- The present study is a continuity of a hazard and vulnerability analysis project along the Makran Coast, Pakistan. We had concluded the hazard assessment part though a multiproxy analysis and published (Haider et al., 2023). The current candidate-publication represents a progressive step towards advancing the vulnerability assessment within the same study area. In this paper, we are adding the findings briefly referring to Haider et al. (2023) publication.
- Is it correct to use 1945 pieces of evidence as a proxy for simulations that adopt present morphology, especially for roughness coefficients governing inland flooding? Doesn’t this affect the simulations?
Before initiating the model simulations, we conducted a morphological comparison of the study area between the present day and 1945. The reason behind is to assess the wave height reported during 1945 along with its devastation affect as of now. This comparison, as outlined in lines 147-152, was based on an analysis of historical topographic maps and current satellite imagery. Additionally, we gathered valuable insights in the field through interviews with senior citizens who could provide firsthand accounts of the topography during the 1945 timeframe, including changes in shoreline, housing, and population density.
Based on the above analysis, we estimated that there have been no significant changes in the coastal morphology since 1945 except density increase in the Pasni town. Moreover, to avoid this error further, the inundation extent is primarily mapped outside the populated areas. Therefore, roughness coefficients governing inland flooding are precise to those in those in 1945.
However, it's important to acknowledge that the results within populated areas are not those of 1945 due to subsequent infrastructure development. The wave impacts in these parts show results as of today. This limitation will be added in the methodology section of our study.
SPECIFIC COMMENTS
Abstract
- Line 12: citing “dynamic and static approaches” before describing them can be misleading, I would change the sentence.
- Line 13: not all readers could have in mind the local geography: where is located the Arabian Sea with respect to the investigation site?
Both comments are addressed together, and initial part of the abstract is revised as advised.
- Line 20: after the point, it is unclear what “It” refers to.
We improved and replaced the pronoun “it” with its proper reference “reflection-amplification phenomenon”
Introduction
- Lines 43-45: the two sentences are very confusing, it is hard to understand their meaning, rephrase them.
We addressed as advised.
Physio-geographical setting and potential tsunamis triggers
- Is paragraph 2.2 necessary? Of course, the source type is interesting and deserves attention, but in the paper it isn’t treated nor cited anymore.
As advised, we are replacing the 2.2 (Gravitational mass wasting) with source type, parameters, and relative locations.
Methods
- Line 108: magnitude 9.5 is extreme, how can the authors justify it? In the previous section, they stated that the maximum expected Mw was 9.2, here they use 9.5. Why?
It seems from the text that the 15m wave scenario is generated by the Mw=9.5 source: what about the other scenarios (7m and 10m)? Did the author obtain them through other seismic sources in the MSZ, presumably smaller?
We clarified our choice of extreme magnitude in response to Reviewer-1's comments also. In addition to addressing this in our previous reply, we provide further explanation below:
We determined the tsunami potential by analysing tsunamite proxies, focusing on the worst-case scenario with extreme morphodynamics along the Oman Coastline, Arabian Sea (see Table S1 in the supplementary material for Tsunamite compilations). These deposits, consisting of block and boulder up to 40 tonnes and reaching heights of 10 meters above mean sea level (msl), demonstrate landward transportation of up to 50 meters from their original locations. Further, laboratory tests on a scaled model (t-LiDAR) of the largest block (conducted by Hoffmann et al., 2013) estimated wave velocities for dislodging, elevating, and transporting these formations to be between 4.5 and 6.6 meters per second (m/s). We modelled this case study to estimate the wave size capable to demonstrate the above scenario.
The above scenario is evaluated and shortlisted after testing various tsunami scenarios using earthquakes source and Okada Parameters. Briefly to your question about the choice of magnitude, our analysis shows that a magnitude of Mw 9.2 resulted in a flow velocity of 3.5 m/s at the site of the boulders (tsunamites). To align with laboratory findings, we increased the magnitude to Mw 9.5, which generated a flow velocity of 5 m/s. Consequently, our study provides an indirect approximation of the maximum earthquake potential. We are revising the language and adding more explanation to improve clarity and comprehension. Also, we are adding details about the source and location of the of the other smaller scenarios (7m and 10 m).
Results and interpretations
- Line 168: the runup usually refers to the maximum elevation reached by the water flooding, so “runup height” doesn’t sound correct.
Thanks for pointing out that. We want to refer “maximum inundation limit”, so we replaced accordingly.
- Line 168: according to Fig. 2A, neither Wadsar nor Parhag are reached by the water.
The 7-meter scenario partially floods Wadsar Town, affecting approximately 30% of its southern area (visual estimates). However, it's important to note that the monitoring point within the town remains un-flooded. Despite the impression that Wadasar is completely inundated, this is not the case. For visual understanding, we refer to the simulation file provided in the supplementary section of the manuscript.
Moving forward, we recognize the importance of working with the regional names such as Wadasr-Prahag area. We intend to dissect both areas in the text for better understanding and will incorporate these revisions in the updated manuscript.
- Line 170: the figure does not report the position of Pasni, that can be inferred from Fig. 1. Placing a label with position of the town can facilitate the reader.
We labelled the Pasni Town in all the figures as advised.
- Lines 172-173: reflection does not occur in this scenario, and commenting on it here sounds incomprehensible.
We removed the sentence as advised.
- Lines 178-179: the cliffs NE of Pasni are not visible in the figure, so they should be indicated.
We indicated the cliff’s location and extent in Figure 1 as advised.
- Lines 179-180: Fig 3B, flow depth graph, doesn’t seem to show two waveforms.
The intense reflection phenomenon and reflection timings are such that, the whole tsunami wave package appears to be a single unit. However, a closer look at the flow depth graph shows small humps (wave troughs) within the big tsunami waveform which mildly shows impact of multiple waves.
- Line 216: where is Gwadar on the map?
We labelled “Gwadar”.
- Line 233: again, Gwadar-hammer-head toponym is not reported in the figure.
We labelled the “Gwadar-hammer-head”.
- Line 290: what does damage probability mean? The methodology should be explained a bit, at least. Moreover, in the picture, Main Bazar seems affected by a probability close to 0, not certainly 0.3.
We explained the damage probability in the methodology section as advised.
We acknowledge this drafting mistake. Also, we appreciate your meticulous observation and extend our thanks. We corrected the value.
Discussion and conclusions
- Line 326: what “hydrodynamics of the period” is referred to? Is hydrodynamics changing with time? Rephrase or explain better.
We recognize the confusion and have addressed. In addition to rephrasing the sentence, we are adding a new sentence to provide better explanation for comprehension.
It's not the hydrodynamics itself that intrinsically changes, but rather we are meant to say the topography, or terrain, that evolves over time. Probably, it is a confusion generated by sentence structure and the terms used. We addressed the issue in the revised manuscript.
- Line 334: tsunamis are usually a sequence of oscillations, where sometimes the second or third peaks are higher than the first. Is reflection the only possibility? Do the reports describe waves coming from different directions, a fact that would confirm the reflection pattern?
You've highlighted an intriguing potential area for future research.
In our analysis based on modeling results, we observed that the first wave tends to have the highest intensity, followed by a series of weaker oscillations from the source. There are instances where the second or third wave, although smaller in size, peaks higher than the first wave upon reaching the coast. Our interpretation suggests that this phenomenon occurs because the first wave has already accumulated significant water volumes and disturbances along the coast, which are then exacerbated by the subsequent waves. Our models indicate that wave reflection is the primary cause of higher second and/or third peaks. This phenomenon is particularly pronounced in Gwadar (as illustrated in Figures 5, 6, and 7, along with the respective simulations). However, in Pasni, the effect is comparatively weaker due to its coastal morphology and shape. There are no reports or information available about the directivity of waves; instead, they typically mention three waves in total.
Exploring the mechanisms behind these wave dynamics and their implications for coastal areas could offer valuable insights into tsunami behaviour and coastal vulnerability, warranting further investigation in the future.
- Line 362: for surface roughness, the authors used the present conditions: are they similar to 1945 ones? Using the present conditions to reconstruct a past event can produce excessive waves dampening, affecting the simulations and the source selection. In 1945 probably the “roughness” was smaller, and maybe a smaller tsunami in sufficient to produce the observed effects. Please discuss this.
We explained the point in detail in first section “General Comments bullet no. 4”. We added a text here also to address the confusion.
- Lines 380-381: apart from vertical structures and sirens, also panels for evacuation routes and, most of all, education of the population is basic.
We will do as advised.
Figures and Tables
- Figure 1: panel A) The symbols used for landslide location are incomprehensible and unrecognisable. Landslide sources are briefly discussed but not used in the simulations, please consider also discarding them. The label Arabian Sea should be moved here from panel B. Panel B) The black line, marking the inundation limit, is not uniform but changes thickness: why?
Panel A) Landslide location and related section are removed/ discarded. The label “Arabian Sea” is moved to panel A.
The variation in thickness of the black line is due to the inclusion of numbers (locality numbers) at specific recording points. The corresponding details for each number can be found in the last column of Table 2. The dashed thin lines connecting these thicker markings depict the lateral trend of the recorded data points.
- Table 2: why Table 2? Where is Table 1?
Table 1 has been included as supplementary material. While it was discussed earlier in the paper, it is not considered of prime importance for the main body of the paper. Therefore, it has been moved to the supplementary section for reference.
- Figures 2, 3, 4, 5, 6, 7: the toponyms are poorly readable on the map. Maybe the authors should consider putting them into a separate box with the corresponding numbers, leaving only these on the map. For a better comparison between the two models, the maps should cover the same domain: as it is now, it isn't easy to assess the differences between the two approaches. The graphs would benefit from adding some ticks on the horizontal axis, to see also fractions of hours.?
We did the changes in the figures and graph as advised.
MINOR ISSUES AND TYPOS
All the typos and terminological adjustments are made as advised.
REFERENCES
Haider, R., Ali, S., Hoffmann, G., Reicherter, K., 2023. A multi-proxy approach to assess tsunami hazard with a preliminary risk assessment: A case study of the Makran Coast, Pakistan. Mar. Geol. 107032. https://doi.org/https://doi.org/10.1016/j.margeo.2023.107032
Hoffmann, G., Reicherter, K., Wiatr, T., Grützner, C., Rausch, T., 2013. Block and boulder accumulations along the coastline between Fins and Sur (Sultanate of Oman): Tsunamigenic remains? Nat. Hazards 65, 851–873. https://doi.org/10.1007/s11069-012-0399-7
Citation: https://doi.org/10.5194/nhess-2023-148-AC2
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