First Tomographic Imaging of Mid-Crustal Doubling at the Abruzzi Outer Thrust Front, Central-Southern Italy

de Nardis, Rita; Talone, Donato; De Siena, Luca; Romano, Maria Adelaide; Brozzetti, Francesco; Lavecchia, Giusy

doi:10.5194/egusphere-2025-3844

Preprints

https://doi.org/10.5194/egusphere-2025-3844

Preprints

18 Sep 2025

| 18 Sep 2025

First Tomographic Imaging of Mid-Crustal Doubling at the Abruzzi Outer Thrust Front, Central-Southern Italy

Rita de Nardis, Donato Talone, Luca De Siena, Maria Adelaide Romano, Francesco Brozzetti, and Giusy Lavecchia

Abstract. The geometry, deep structural style, and seismotectonic setting of the outer Abruzzi thrust system are less understood than those of other segments of Italy's Late Pliocene–Quaternary contractional belt. This knowledge gap arises from the region's complex surface geology, low seismicity rates, and the limited resolution of existing geophysical data.

Here, we present a local earthquake tomography of a large and previously unexplored area that encompasses the Abruzzi thrust system and spans from the Apennine extensional province in the west to the foreland strike-slip province in the east. The model is based on the inversion of 42,176 P-wave and 29,045 S-wave arrival times from earthquakes with M_L ranging from 0.2 to 5.5.

Our results show low seismic velocities at upper crustal levels in the western sectors, correlating with continental basins of the extensional domain. In contrast, marked Vp inversions at mid- to lower-crustal depths in the eastern sector delineate a crustal doubling.

We interpret the tomographic results in the context of geological, geophysical, and seismological data to construct a 3D conceptual model of the region. This includes the first geometric reconstruction of the Abruzzi Arc basal thrust, an eastward convex arcuate structure extending ~170 km and reaching depths of ~24 km. The model also incorporates strike-slip faults in the footwall and east-dipping normal faults to the west.

The structural affinity between the Abruzzi Arc basal thrust and other seismogenic structures of the Padan–Adriatic belt located in the same structural position, suggests potential seismogenic behavior, although slow deformation rates and long recurrence intervals obscure its seismic expression. This conceptual model provides new insights into regional geodynamics and has significant implications for seismic hazard assessment in the central–southern Apennine transition zone.

Received: 07 Aug 2025 – Discussion started: 18 Sep 2025

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.

Download & links

Preprint (PDF, 3774 KB)

Supplement (5214 KB)

Download & links

Rita de Nardis, Donato Talone, Luca De Siena, Maria Adelaide Romano, Francesco Brozzetti, and Giusy Lavecchia

Status: final response (author comments only)

RC1:
'Comment on egusphere-2025-3844', Anonymous Referee #1, 22 Nov 2025

GENERAL COMMENTS

The manuscript “First Tomographic Imaging of Mid-Crustal Doubling at the Abruzzi Outer Thrust Front, Central-Southern Italy” by De Nardis et al. presents a local earthquake tomography study of the Outer Abruzzi Thrust Front in Central Italy. By integrating Vp and Vs models with geological, geophysical, and seismological information, the Authors propose a three-dimensional conceptual model of the crustal structure, including a geometric reconstruction of the basal thrust of the Abruzzi Arc. The study addresses a geologically significant region and has the potential to provide valuable insights into the geodynamics and seismic hazard of the central Apennines. While the topic is appropriate for Solid Earth and the manuscript is generally well written, several substantive issues remain, mainly concerning the tomographic inversion and the resolution of the resulting models. On this basis, I recommend publication after major revision.

SPECIFIC COMMENTS

For the tomographic inversion the Authors used the Fast-Marching Tomography algorithm (FMTOMO). Although the Authors properly cite the related literature, the manuscript lacks a concise explanation of how the algorithm works. A brief methodological description would substantially strengthen the paper by allowing readers to better understand the inversion setting and assess the reliability of the results. For example, the manuscript mentions the use of two different grids (the propagation grid and the velocity grid) but it remains unclear why they differ and how each is employed during ray tracing and velocity inversion.

The P- and S-wave velocity models are displayed using effective velocity values, but the chosen color scales do not adequately highlight the anomalies discussed in the text. Adopting color scales with stronger contrasts, ideally diverging around appropriate background reference values, would improve the readability and interpretation of the results.

Figure 5a presents multiple cross-sections with different orientations, yet only four are shown clearly. All sections should be displayed, at least in the Supplementary Material, to provide a more complete visualization of the Vp model. The treatment of seismicity also requires improvement. Relocated earthquakes are shown only in Figure 5a, and the varying orientations of the sections hinder a coherent assessment of the relationship between seismicity and velocity structure. A map displaying the whole relocated dataset, along with seismicity plotted on each tomographic section, would greatly clarify this aspect.

Additional ambiguity arises from the statements in lines 164–166 and 203–204, where the Authors indicate that seismicity was used to interpret the 3D velocity models and to construct the final 3D fault model. It is not stated, however, which seismicity dataset was actually used. Without this information, it is impossible to properly evaluate the modelling strategy. The authors should clearly specify whether the interpretation relies solely on relocated events, only on catalogue data, or on both, and they should provide a justification for their approach.

The assessment of model resolution also requires a more comprehensive analysis and evaluation. The Authors performed three checkerboard (CB) tests with different cell sizes, but they show in the Supplementary material results only at 10 km depth. A complete evaluation of the tomographic models cannot be made without access to the full CB test results. Maps at multiple depths for all three tests should be provided, at least in the Supplementary Material. Furthermore, in the manuscript is not reported any comparison between the sizes of CB cells with those of the anomalies interpreted in the real velocity models. Without such a comparison, it is difficult to distinguish between robust anomalies and those that may be artefacts. In this framework, some more layers are actually displayed in Figure 4, but for these maps the cell dimension is not specified. At a pure visual inspection, it seems that the CB model shown is the one with 15 km horizontal and 12 km vertical cell size. Is it correct? The recovered model exhibits unexpectedly reduced resolution at 8 km depth compared to the layers above and below. The authors should explain how this behaviour was evaluated and why it occurs.

Finally, the authors state in lines 242–243 that the velocity models are well resolved down to 20 km and locally to approximately 24 km. However, the CB test of Fig. 4 indicates poor recovery at 20 km depth. Since one of the main features discussed in the manuscript lies within roughly 14–24 km, the resolution of this depth interval needs to be carefully revised and reassessed to avoid potentially misleading interpretations.

TECHNICAL CORRECTIONS

In Figure 1a the FM solutions are reported with red or light-red background. Explain in the caption the difference.

The temporal range of the historical earthquakes shown in Figure 2a is not specified. Add this information in the caption.

Caption of Figure 3: the sentence “Red circles and green-blue contour lines as in legend panel d.” should be moved in the description of panel b.

Line 215: Fig. S5 or Fig. 5?

Line 496: “(see yellow dots in Fig.7)”. It should be “squares”.

Citation: https://doi.org/10.5194/egusphere-2025-3844-RC1
- AC1: 'Reply on RC1', Rita De Nardis, 23 Dec 2025
  
  REVIEWER#1 (R#1)
  General Comments
  The manuscript “First Tomographic Imaging of Mid-Crustal Doubling at the Abruzzi Outer Thrust Front, Central-Southern Italy” by de Nardis et al. presents a local earthquake tomography study of the Outer Abruzzi Thrust Front in Central Italy. By integrating Vp and Vs models with geological, geophysical, and seismological information, the Authors propose a three-dimensional conceptual model of the crustal structure, including a geometric reconstruction of the basal thrust of the Abruzzi Arc. The study addresses a geologically significant region and has the potential to provide valuable insights into the geodynamics and seismic hazard of the central Apennines. While the topic is appropriate for Solid Earth and the manuscript is generally well written, several substantive issues remain, mainly concerning the tomographic inversion and the resolution of the resulting models. On this basis, I recommend publication after major revision.
  Response (Res)
  We sincerely appreciate the Reviewer’s positive overall assessment of the manuscript, including the recognition of the geological importance of the study area and the potential implications of our findings for the geodynamics and seismic hazard of the central Apennines. We also thank the Reviewer for noting that the manuscript is generally well written.
  We fully concur that the main aspects requiring improvement concern the tomographic inversion procedure and the assessment of model resolution. In the revised manuscript, we have carefully addressed these points by: (1) expanding and clarifying the methodological approach, and (2) adding a new section titled “Parametrization and Model Resolution,” which provides a more detailed description of the parametrization in accordance with the Reviewer’s specific suggestions.
  In addition, we have strengthened the evaluation of model reliability by adding and reorganizing figures in the Supplementary Material, including resolution and sensitivity analyses, to provide a more transparent assessment of data quality and the robustness of the resulting Vp and Vs models. We note that this material, although not previously shown, was available to us and has now been fully reorganized and presented.
  To analyse the depth constraints in more detail, following Rawlinson & Spakman (2016), we have supplemented the checkerboard test with an additional spike test in the deepest part toward the NW. We believe that these revisions significantly improve the clarity, reproducibility, and reliability of the study.
  In accordance with the journal’s revision procedure, at this stage authors are required solely to respond to the issues raised by the reviewers and are not requested to resubmit the revised manuscript. Consequently, although the manuscript has been revised accordingly, we have not indicated the specific changes with line numbers; instead, we refer only to the relevant sections.
  SPECIFIC COMMENTS
  R#1
  For the tomographic inversion the Authors used the Fast-Marching Tomography algorithm (FMTOMO). Although the Authors properly cite the related literature, the manuscript lacks a concise explanation of how the algorithm works. A brief methodological description would substantially strengthen the paper by allowing readers to better understand the inversion setting and assess the reliability of the results. For example, the manuscript mentions the use of two different grids (the propagation grid and the velocity grid) but it remains unclear why they differ and how each is employed during ray tracing and velocity inversion.
  Res
  
  Preparing a multidisciplinary manuscript requires a careful balance among the different disciplines involved. In our effort to harmonize the text, we inadvertently devoted insufficient space to a detailed description of the FMTOMO algorithm. We thank the Reviewer for this constructive comment.
  
  In the revised manuscript, we have added a concise yet comprehensive methodological description of the FMTOMO algorithm to clarify how travel times, ray paths, and velocity model updates are computed. In particular, we now explicitly describe 1) the forward and inversion methods and the role of the two grids used by FMTOMO: (i) the propagation grid, on which the fast-marching method solves the eikonal equation and computes first-arrival travel times, and (ii) the velocity grid, which defines the parameterization of the inversion model.
  
  Travel times are calculated on the finer propagation grid to ensure numerical stability and accuracy. In contrast, velocity perturbations are inverted on the coarser velocity grid to reduce the number of free parameters and stabilise the inversion. Ray paths are reconstructed by backtracking along the normal to the wavefront. This description has been incorporated into the Materials and Methods section to allow readers to better assess the inversion framework and the reliability of the resulting velocity models.
  R#1
  
  The P- and S-wave velocity models are displayed using effective velocity values, but the chosen color scales do not adequately highlight the anomalies discussed in the text. Adopting color scales with stronger contrasts, ideally diverging around appropriate background reference values, would improve the readability and interpretation of the results.
  Res
  
  We thank the Reviewer for this comment. We chose the absolute velocities color scales by trying to avoid strong contrasts according to the literature on the use of color scales (Golebiowska and Çöltekin, 2022; Stoelzle and Stein, 2021; Zhou and Hansen, 2016). Nevertheless, we have improved the visualization of both P- and S-wave velocity models by adopting color scales with enhanced contrast. Specifically, we now show both absolute velocity models and relative velocity perturbations with respect to the reference model in the Supplementary Material using diverging color scales centered on zero. This choice allows the reader to better identify and compare velocity anomalies discussed in the text and to clearly distinguish between background structure and significant deviations.
  
  R#1
  
  Figure 5a presents multiple cross-sections with different orientations, yet only four are shown clearly. All sections should be displayed, at least in the Supplementary Material, to provide a more complete visualization of the Vp model.
  Res
  
  We thank the Reviewer for this suggestion. We have revised Figure 5a to include only the cross-sections discussed in the main text, improving readability. For completeness, we have added new figures in the Supplementary Material showing all tomographic cross-sections used in this study, for both absolute and relative velocity models.
  
  R#1
  
  The treatment of seismicity also requires improvement. Relocated earthquakes are shown only in Figure 5a, and the varying orientations of the sections hinder a coherent assessment of the relationship between seismicity and velocity structure.
  
  A map displaying the whole relocated dataset, along with seismicity plotted on each tomographic section, would greatly clarify this aspect.
  Res
  
  We thank the Reviewer for highlighting this important point. In the revised manuscript, we have clarified the treatment of seismicity and its role in the interpretation. A new map showing the entire relocated earthquake dataset has been added in the Supplementary Material, and seismicity is now consistently projected onto each tomographic section to facilitate a coherent comparison with the velocity structure.
  
  R#1
  
  Additional ambiguity arises from the statements in lines 164-166 and 203-204, where the Authors indicate that seismicity was used to interpret the 3D velocity models and to construct the final 3D fault model. It is not stated, however, which seismicity dataset was actually used. Without this information, it is impossible to properly evaluate the modelling strategy. The authors should clearly specify whether the interpretation relies solely on relocated events, only on catalogue data, or on both, and they should provide a justification for their approach.
  Res
  
  As suggested, we have better clarified which seismicity datasets were used. The seismic tomography and the construction of the final 3D fault model rely on the relocated earthquake catalogue from ISIDe database (ISIDe Working Group, 2007), while the other catalogues of seismicity were used during the interpretation and validation phases. This distinction is now explicitly stated in the manuscript, together with a justification of the adopted approach.
  R#1
  
  The assessment of model resolution also requires a more comprehensive analysis and evaluation. The Authors performed three checkerboard (CB) tests with different cell sizes, but they show in the Supplementary material results only at 10 km depth. A complete evaluation of the tomographic models cannot be made without access to the full CB test results. Maps at multiple depths for all three tests should be provided, at least in the Supplementary Material.
  Res
  
  Following the Reviewer's comments, we have included the resolution analysis of all checkerboard tests at multiple depth levels. These results are now shown in the new section "Parametrization and Model Resolution" and provide a more complete evaluation of the spatial resolution of the tomographic models.
  R#1
  
  Furthermore, in the manuscript is not reported any comparison between the sizes of CB cells with those of the anomalies interpreted in the real velocity models. Without such a comparison, it is difficult to distinguish between robust anomalies and those that may be artefacts.
  
  In this framework, some more layers are actually displayed in Figure 4, but for these maps the cell dimension is not specified. At a pure visual inspection, it seems that the CB model shown is the one with 15 km horizontal and 12 km vertical cell size. Is it correct?
  Res
  
  We agree that comparing the size of checkerboard cells with the dimensions of interpreted anomalies is essential. In the "Parametrization and Model Resolution" section, we explicitly discuss this comparison, clarifying which velocity anomalies are larger than the resolving length indicated by the checkerboard tests and can therefore be considered robust. We also include the three CBs analysed for Vp and Vs at different depths.
  R#1
  
  The recovered model exhibits unexpectedly reduced resolution at 8 km depth compared to the layers above and below. The authors should explain how this behaviour was evaluated and why it occurs.
  Res
  
  The reduced resolution observed at approximately 8 km depth has now been explicitly addressed in the manuscript. It is mainly due to the position of the horizontal slice, which coincided with the abrupt change in the synthetic velocity model (i.e., the boundary between cells with positive and negative velocity variations).
  R#1
  
  Finally, the authors state in lines 242-243 that the velocity models are well resolved down to 20 km and locally to approximately 24 km. However, the CB test of Fig. 4 indicates poor recovery at 20 km depth. Since one of the main features discussed in the manuscript lies within roughly 14-24 km, the resolution of this depth interval needs to be carefully revised and reassessed to avoid potentially misleading interpretations.
  Res
  
  We acknowledge the Reviewer's concern regarding the resolution of the 14-24 km depth interval, which hosts one of the main features discussed in the manuscript. In the revised manuscript, we show the coarse, medium, and fine checkerboards at different depths and discuss the model resolution accordingly (Parametrization and Model Resolution section). Moreover, following Rawlinson & Spakman (2016), we have supplemented the checkerboard test with an additional spike test in the deepest part toward the NW.
  TECHNICAL CORRECTIONS
  
  R#1
  
  In Figure 1a the FM solutions are reported with red or light-red background. Explain in the caption the difference.
  
  Res
  
  We thank the reviewer for the observation. The requested clarification has been added to the caption of Figure 1a.
  
  R#1
  
  The temporal range of the historical earthquakes shown in Figure 2a is not specified. Add this information in the caption.
  
  Res
  
  We thank the reviewer for this comment. We have now specified in the caption of Figure 2a the temporal range of the CPTI15 v4.0 catalogue (Rovida et al., 2020, 2022) used to represent the earthquakes.
  
  R#1
  
  Caption of Figure 3: the sentence "Red circles and green-blue contour lines as in legend panel d." should be moved in the description of panel b.
  
  Res
  
  The caption has been revised accordingly.
  
  R#1
  
  Line 215: Fig. S5 or Fig. 5?
  
  Res
  
  The correct reference is "Figure 5", and the text has been amended.
  
  R#1
  
  Line 496: "(see yellow dots in Fig.7)". It should be "squares".
  
  Res
  
  This correction has been implemented.
  References
  1. Zhou, L. and Hansen, C. D.: A Survey of Colormaps in Visualization, IEEE Trans. Visual. Comput. Graphics, 22, 2051-2069, https://doi.org/10.1109/TVCG.2015.2489649, 2016.
  
  2. Stoelzle, M. and Stein, L.: Rainbow color map distorts and misleads research in hydrology - guidance for better visualizations and science communication, Hydrol. Earth Syst. Sci., 25, 4549-4565, https://doi.org/10.5194/hess-25-4549-2021, 2021.
  
  3. Golebiowska, I. and Çöltekin, A.: What's wrong with the rainbow? An interdisciplinary review of empirical evidence for and against the rainbow color scheme in visualizations, ISPRS Journal of Photogrammetry and Remote Sensing, 194, 195-208, https://doi.org/10.1016/j.isprsjprs.2022.10.002, 2022.
  
  4. ISIDe Working Group: Italian Seismological Instrumental and Parametric Database (ISIDe), https://doi.org/10.13127/ISIDE, 2007.
  
  5. Rawlinson N., W. Spakman, On the use of sensitivity tests in seismic tomography, Geophysical Journal International, Volume 205, Issue 2, 01 May 2016, Pages 1221-1243
  
  On behalf of all co-authors, we thank the Reviewer for the constructive and insightful comments.
  Best Regards
  Rita de Nardis and Donato Talone
  
  Citation: https://doi.org/10.5194/egusphere-2025-3844-AC1
RC2:
'Comment on egusphere-2025-3844', Anonymous Referee #2, 17 Dec 2025
Main comment
Review of the manuscript “First Tomographic Imaging of Mid-Crustal Doubling at the Abruzzi Outer Thrust Front, Central-Southern Italy” by Rita de Nardis, Donato Talone, Luca De Siena, Maria Adelaide Romano, Francesco Brozzetti and Giusy Lavecchia submitted for publications to Solid Earth.
This work presents a newest addition to the research of the complex crustal structure of the Abruzzi Outer Thrust Front in Central-Southern Italy. The investigation mostly relies on results from local body wave tomography with addition of other geological, geophysical, and seismological information. The main finding of this study is the geometric reconstruction of the basal thrust of the Abruzzi Arc along with new the Vp and Vs 3D models of the region. The topic of investigation is interesting, and the methods used are sound and my main critique of the manuscript is mostly about the usage of the tomography method and presentation of the results. The language used is appropriate and reads easily but the overall impression is that the manuscript overly complex with some parts hard to follow due to branching at too many findings and discussion of previous result (tomography, seismicity, FMS, geology, macroseismic, etc.). In my opinion not all these results are necessary in the process of getting the main result - mapping of the basal thrust – and manuscript would benefit from focusing on this and then discussing previous results in the context of the new findings.
Bellow, please find the more specific comments that I suggest authors address before the manuscript can be considered for publication.

Specific comments
All the seismological methods used are relatively poorly journaled i.e. the details of each processing step should be better explained and discussed. Although all the methods used are well known and used a brief description of each method would be beneficial along with discussion on potential problems when applying them. This is especially relevant for the main result – tomographic image of the central Italy. The Authors perform tomography using the Fast-Marching method as implemented in FMTOMO package, but the relevant details of the method are not discussed in the context of this research. Furthermore, the Authors discuss setting of the tomographic inversion process along with synthetic tests in three separate sections (in Method, Appendix and Supplement) therefore not allowing the reader to properly follow the whole process. I would suggest this be done in the main part of the manuscript. Synthetic tests done are good but showing of these results is poor. Why not show the input checkerboard at each depth along with resulting inversion? Why not show the results of the checkerboard inversion along some of the more relevant cross-sections shown in Fig 5. (sections 1- 4) so reader can see how well they perform at depth. Authors state that there is good resolution at depths of 20 km and even at 24 km but from Fig 4. this is not obvious. Also, what about poor resolution in upper crust (Fig. 4 – 8 km depth)? The spike test is excellent addition to the synthetic test but discussion about resolution for negative over positive anomaly (section 1 and 3 in Fig S10) is not discussed. Is there any resolution in this case and does it resolve this anomaly? How do the Authors comment on this. As the tomography is the most important result of this work on which the main conclusion of the manuscript stands it needs to be discussed and journaled in detail.
Also, some discussed details are not clear. For example, what is propagation grid and what is inversion grid. Why is the propagation grid 4.5 km above sea level? And other such details.
Please comment on RMS and covariance of tomography. Is RMS good enough?
Similarly, a lot of discussion in this work is based on relocated seismicity but details of the relocation process are few especially in the context of used 1D model. How do the new locations differ from old ones? Is there significant difference? Please add more information and discussion to this part.
Focal mechanism inversion part seems especially out of place. It is only very briefly described without any details, and it is done only for one peculiar set of data. Where there more datasets where this could be done?
Please emphasize more how the lower part of the basal thrust was mapped. It was extrapolated from tomography results but it is not clear exactly how.
Figures
A lot of figures suffer from too many details crammed in one image. For example, why show subfigure with GPS velocity (Fig 1c.) from other investigations without explaining it properly or use it in current work? Also, details in that image are not visible. Is this horizontal velocity or vertical velocity.

Figure 2. please change marking from a, b’, b’’ and c to a, b, c, d.

Figure 3. Is especially hard to get through with too many details show and some not properly explained or used in the main text. For example, what is shown in subfigure 3d? What is kernel density? Where is this used in the text. How was this calculated? I can’t see any green circles in Fig 3. as mentioned in figure caption.

Figures S13 and S14. In which sense does the Authors apply extrapolated? Why was this done? The grid spacing in depth was 2 km was the extrapolation necessary? Please explain.

Figure 5. Please reduce number of profiles shown in uppermost image as currently nothing can be seen with these many profiles in same image. How was the red line marking basal thrust shown in this image inferred here?

Technical corrections
- Line 18 “…marked Vp inversion…” Inversion in which sense? Decrease in velocity with depth or …?
- Line 215 Fig. S5 -> Fig. 5
- Line 319 (green dots… -> (green and blue dots…
Citation: https://doi.org/10.5194/egusphere-2025-3844-RC2

Rita de Nardis, Donato Talone, Luca De Siena, Maria Adelaide Romano, Francesco Brozzetti, and Giusy Lavecchia

Supplement

https://doi.org/10.5194/egusphere-2025-3844-supplement

Rita de Nardis, Donato Talone, Luca De Siena, Maria Adelaide Romano, Francesco Brozzetti, and Giusy Lavecchia

Viewed

Total article views: 977 (including HTML, PDF, and XML)

HTML	PDF	XML	Total	Supplement	BibTeX	EndNote
824	132	21	977	61	34	43

HTML: 824
PDF: 132
XML: 21
Total: 977
Supplement: 61
BibTeX: 34
EndNote: 43

Views and downloads (calculated since 18 Sep 2025)

Month	HTML	PDF	XML	Total
Sep 2025	592	25	5	622
Oct 2025	55	26	4	85
Nov 2025	69	30	4	103
Dec 2025	57	27	7	91
Jan 2026	51	24	1	76

Cumulative views and downloads (calculated since 18 Sep 2025)

Month	HTML	PDF	XML	Total
Sep 2025	592	25	5	622
Oct 2025	55	26	4	85
Nov 2025	69	30	4	103
Dec 2025	57	27	7	91
Jan 2026	51	24	1	76

Viewed (geographical distribution)

Total article views: 967 (including HTML, PDF, and XML) Thereof 967 with geography defined and 0 with unknown origin.

Country	#	Views	%

Latest update: 29 Jan 2026

Short summary

The Outer Thrust System (OTS) in coastal Abruzzi (Italy) remains debated in terms of its geometry, seismic activity, and deformation style. This study presents a new seismic tomography of the Abruzzi Arc basal thrust, revealing mid-crustal doubling at depths of 14–24 km. The conceptual 3D model highlights deep compressive tectonics influencing the crustal structure. If the thrust is seismogenic, it could have significant implications for regional geodynamics and seismic hazard assessment.


Total:	0
HTML:	0
PDF:	0
XML:	0