Recent Activity and Kinematics of the Bounding Faults of the Catanzaro Trough (Central Calabria, Italy): New Morphotectonic, Geodetic and Seismological Data
, Fabio Brighenti 1, Francesco Carnemolla 1, Giorgio De Guidi 1,3, Carmelo Monaco 1,2,3,*, Fabrizio Pepe 4 and Luciano Scarfì 2
Antonio Casas
Round 1
Reviewer 1 Report
The paper deals with an interesting case study of seismotectonic analysis of an active area. It is a particular case, but of interest for a wide audience. It is well written and figures are of good quality. Only minor spelling corrections.
My only comment is that Ercynian in this paragraph should be Hercynian or Variscan
2.2. The Catanzaro Trough
The Catanzaro Basin is filled by Pliocene-Quaternary sedimentary sequences, con-
sisting of marine and continental deposits, unconformably lying on the CA structural
units [47, 48; 49] (Figure 1B). The CA units encompass Ercynian m
Author Response
The paper deals with an interesting case study of seismotectonic analysis of an active area. It is a particular case, but of interest for a wide audience. It is well written and figures are of good quality. Only minor spelling corrections.
Response. We thank the reviewer for the appreciation of the work. Spelling corrections have been carried out.
My only comment is that Ercynian in this paragraph should be Hercynian or Variscan
2.2. The Catanzaro Trough
The Catanzaro Basin is filled by Pliocene-Quaternary sedimentary sequences, con-
sisting of marine and continental deposits, unconformably lying on the CA structural
units [47, 48; 49] (Figure 1B). The CA units encompass Ercynian m
Response. Agree. We have modified the text as suggested.
Reviewer 2 Report
This manuscript refers to the study of the Catanzaro Trough, Italy, from seismological, geodetic and morphotectonic data, as well as diverse collected tectonic information. In my opinion, concerning the manuscript, it is interesting, the methodology is well presented, and on the whole, it is well structured and well writing. The manuscript is suitable for publication after to consider some points and better explain and justify some issues, as outlined below.
Major issues:
- Page 7. It is not totally clear in the manuscript if the relocation process was done specifically for this work or it was conducted previously (reference [23]). This issue needs a specific section in order to give more details on the followed process. Uncertainties in the final locations also must be considered.
- Pages 10 and 11. Not the data but the processing of the GNSS data need a better explanation, not only to show the used software. Why vertical velocities are not computed? To show the error (confidence) ellipses in figure 8 is necessary in a plot like this. Results should be discussed and compared with previous works in the region, as that conducted by Palano et al. (2012).
Page 13. The computation of the maximum expected magnitude must be improved. Just to use the W&C relationship without to give uncertainties is a poor estimation. Why not to use directly the SRL instead of some estimation of the RLD? Maybe the recent works by Pace et al. (2016) and Medina Casacales et al. (2020) could give the authors some suggestions.
Minor issues:
- The term ‘kinematics’, used along all the manuscript including the title, is something ambiguous. It implies more than to know the type of fault, but to know movement rates of the fault. This must be discussed in the manuscript.
- In the abstract section. Check the sentence ‘macroseismic fields’. Do the authors mean ‘macroseismic intensity distribution’?
- Page 2. Seismogenic potential cannot be used for seismic hazard purposes if time information (v.g., return period, occurrence of paleoseismic events, etc.) is not available. In any case, seismogenic or seismic potential is interesting by itself. References 27 and 28 in figure 1A caption are not ordered. Figures 1A and 1B are very small, and it is difficult to see the showed features. Why not to enlarge them showing the two figures one below the other?
- Page 3. In figure 2B caption, what means ‘from [33] modified’? What is that was modified, the figure or the seismogenic sources? In the same figure, references 33 to 39 are not ordered. As in the previous figure 1, figures 2A and 2B are hard to check. Why not to enlarge them? In addition, maybe changing the tone of the shading of the DEM, and the color of seismicity figures, figures could be more readable.
- Page 4. Sentence ‘This area was the place … ’ must finish in ‘… [16]) earthquakes.’
- Page 5. In figure 3A caption, ‘… fault inferrend …’ must be ‘… fault inferred …’. Figures 3A and 3B should be improved changing the tone of the shading of the DEM, and changing at least the color and thickness of the inferred fault. Colors of terraces in figure 3A should be highlighted.
- Page 6. ’10-15 Km’ must be ’10-15 km’.
- Page 8. Figure 5 (plots S1 to S10) should be improved increasing the size of the events and the thickness of the lines.
-Page 10. References 65 to 67 do not follow the required format.
- Page 13. … affected by mistakes …? Please rewrite. The sentence ‘… we assume that this fault could be associated to the 28 March 1783 earthquake’ needs be justified … even erased. More taking into account that authors state in page 2: ‘However, the epicentral location of this shock and other earthquakes that occurred in the same area is still debated’.
- Along the manuscript. Please use Nubia or Nubian plate instead of Africa plate. When use macroseismic intensity values authors should use always roman numerals.
Medina-Cascales, I., Martin-Rojas, I., García-Tortosa, F.J., Peláez, J.A., Alfaro, P. (2020). Geometry and kinematics of the Baza Fault (central Betic Cordillera, South Spain): insights into its seismic potential. Geologica Acta 18.11, 1-25.
Pace, B., Visini, F., Peruzza, L. (2016). FiSH: MATLAB tools to turn fault data into Seismic-Hazard Models. Seismological Research Letters 87, 374-386.
Palano, M., Ferranti, L., Monaco, C., Mattia, M., Aloisi, M., Bruno, V., Cannavò, F., and Siligato, G. (2012). GPS velocity and strain fields in Sicily and southern Calabria, Italy: Updated geodetic constraints on tectonic block interaction in the central Mediterranean. Journal of Geophysical Research 117, B07401.
Author Response
This manuscript refers to the study of the Catanzaro Trough, Italy, from seismological, geodetic and morphotectonic data, as well as diverse collected tectonic information. In my opinion, concerning the manuscript, it is interesting, the methodology is well presented, and on the whole, it is well structured and well writing. The manuscript is suitable for publication after to consider some points and better explain and justify some issues, as outlined below.
Response: we thank the reviewer for the appreciation of the work and for his helpful comments that will surely improve the manuscript. Point-by-point responses to the reviewer’s comments are listed below.
Major issues:
- Page 7. It is not totally clear in the manuscript if the relocation process was done specifically for this work or it was conducted previously (reference [23]). This issue needs a specific section in order to give more details on the followed process. Uncertainties in the final locations also must be considered.
Response: agree. Starting from the parameters provided by the seismic catalogs, we relocated the event using a double-difference (DD) algorithm implemented in the tomoDDPS code [59]. The software is able to improve the locations by using a combination of absolute and differential arrival-time readings between couples of closed-spaced earthquakes, and by computing the seismic ray-tracing in a 3D velocity model - in the study we used the model of Scarfì et al. [23], suitable for the Calabrian area. We rewrote the sentence for clarity. In addition, data relating to the uncertainties of the final locations have been added.
- Pages 10 and 11. Not the data but the processing of the GNSS data need a better explanation, not only to show the used software. Why vertical velocities are not computed? To show the error (confidence) ellipses in figure 8 is necessary in a plot like this. Results should be discussed and compared with previous works in the region, as that conducted by Palano et al. (2012).
Response: agree. We have added a better explanation on GNSS data processing and compared with the previous works in the region conducted by Palano et al. (2012). We did not considered the vertical velocity because it is the less precise component in the GNSS measurements due to instruments set-up, seasonal variation, ocean tide, etc. Furthermore, for maximum accuracy along the vertical component, continuous measurements would be necessary.
Page 13. The computation of the maximum expected magnitude must be improved. Just to use the W&C relationship without to give uncertainties is a poor estimation. Why not to use directly the SRL instead of some estimation of the RLD? Maybe the recent works by Pace et al. (2016) and Medina Casacales et al. (2020) could give the authors some suggestions.
Response: agree. We changed the computation of the maximum expected magnitude using directly the SRL from the W&C relationships, even though we did not consider the uncertainties because the standard deviation is already included in the W&C formulas. Anyway, for going into the matter more thoroughly, we also cited the works by Pace et al. (2016).
Minor issues:
- The term ‘kinematics’, used along all the manuscript including the title, is something ambiguous. It implies more than to know the type of fault, but to know movement rates of the fault. This must be discussed in the manuscript.
Response: disagree. This is the definition of the term “kinematics” in the Glossary of the book “Structural Geology” by Haakon Fossen:
Kinematics: From Greek “kinema”, meaning motion. The description of how rock masses or objects in rocks move as a result of deformation.
Kinematic indicator: Any structure indicating the sense of shear or transport during a deformation event. Examples include shear bands in mylonites, rotated porphyroclasts, drag folds and Riedel shears associated with faults.
Therefore, we used the term “kinematics” in its common meaning that is the branch of mechanics concerned with the motion of objects without reference to the forces which cause the motion or to the movement rates.
- In the abstract section. Check the sentence ‘macroseismic fields’. Do the authors mean ‘macroseismic intensity distribution’?
Response: agree. We have modified the text as suggested.
- Page 2. Seismogenic potential cannot be used for seismic hazard purposes if time information (v.g., return period, occurrence of paleoseismic events, etc.) is not available. In any case, seismogenic or seismic potential is interesting by itself. References 27 and 28 in figure 1A caption are not ordered. Figures 1A and 1B are very small, and it is difficult to see the showed features. Why not to enlarge them showing the two figures one below the other?
Response: agree. We deleted the second part of the sentence “useful for seismic hazard purposes”. We ordered the references in figure 1A caption and enlarged the two figure as suggested.
- Page 3. In figure 2B caption, what means ‘from [33] modified’? What is that was modified, the figure or the seismogenic sources? In the same figure, references 33 to 39 are not ordered. As in the previous figure 1, figures 2A and 2B are hard to check. Why not to enlarge them? In addition, maybe changing the tone of the shading of the DEM, and the color of seismicity figures, figures could be more readable.
Response: agree. We have better specified. The seismogenic sources are from literature (authors are quoted in the caption, included [33]), but a similar figure was published by [33] (in the new version [29]) and we have added in the caption: “…from literature (see also…)”. Moreover, we ordered the references in the caption and improved the two figure as suggested.
- Page 4. Sentence ‘This area was the place … ’ must finish in ‘… [16]) earthquakes.’
Response: agree. We have modified the text as suggested.
- Page 5. In figure 3A caption, ‘… fault inferrend …’ must be ‘… fault inferred …’. Figures 3A and 3B should be improved changing the tone of the shading of the DEM, and changing at least the color and thickness of the inferred fault. Colors of terraces in figure 3A should be highlighted.
Response: agree. We have modified the figure 3A caption and the figures 3A and 3B as suggested.
- Page 6. ’10-15 Km’ must be ’10-15 km’.
Response: agree. We have modified the text as suggested.
- Page 8. Figure 5 (plots S1 to S10) should be improved increasing the size of the events and the thickness of the lines.
Response: aartial agree: increasing the size of the events is impossible, as they would overlap excessively. The thickness of the lines was increased.
-Page 10. References 65 to 67 do not follow the required format.
Response: agree. We have modified the text as suggested.
- Page 13. … affected by mistakes …? Please rewrite. The sentence ‘… we assume that this fault could be associated to the 28 March 1783 earthquake’ needs be justified … even erased. More taking into account that authors state in page 2: ‘However, the epicentral location of this shock and other earthquakes that occurred in the same area is still debated’.
Response: agree. We have modified the text as suggested.
- Along the manuscript. Please use Nubia or Nubian plate instead of Africa plate. When use macroseismic intensity values authors should use always roman numerals.
Response: agree. We have modified the text as suggested.
Medina-Cascales, I., Martin-Rojas, I., García-Tortosa, F.J., Peláez, J.A., Alfaro, P. (2020). Geometry and kinematics of the Baza Fault (central Betic Cordillera, South Spain): insights into its seismic potential. Geologica Acta 18.11, 1-25.
Pace, B., Visini, F., Peruzza, L. (2016). FiSH: MATLAB tools to turn fault data into Seismic-Hazard Models. Seismological Research Letters 87, 374-386.
Palano, M., Ferranti, L., Monaco, C., Mattia, M., Aloisi, M., Bruno, V., Cannavò, F., and Siligato, G. (2012). GPS velocity and strain fields in Sicily and southern Calabria, Italy: Updated geodetic constraints on tectonic block interaction in the central Mediterranean. Journal of Geophysical Research 117, B07401.
Response: we added the references.
