TY - JOUR
T1 - Tectonic geomorphology-based modeling reveals dominance of transpression in Taxila and the contiguous region in Pakistan
T2 - implications for seismic hazards
AU - Talha Qadri, S. M.
AU - Shah, Afroz A.
AU - Sahari, S.
AU - Raja, Afia
AU - Yaghmaei-Sabegh, Saman
AU - Khan, Mohammad Younis
N1 - Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
PY - 2023/3
Y1 - 2023/3
N2 - Mapping active tectonic features remains a critical step in understanding earthquake hazards and producing reliable and scientifically robust maps. The mapping is often combined with seismological, geological, geodetic, and structural datasets to improve the overall quality of the maps. However, site response analysis is usually not connected with a typical active tectonic mapping exercise, which is a significant problem in improving earthquake hazard mapping. The motivation of the present study is to demonstrate the robustness of methodology where mapping of active tectonic features is combined with the site response analysis, thus mapping the earthquake sources and the seismic amplification potential of the region. Initially, tectonic geomorphological mapping was done by manually tracing the evidence of faulting, including the topographic breaks, earthquake ruptures, ridge crests, deflected streams, triangular facets, and so on. The cross-cutting relationships between the faults and the Holocene sedimentary deposits differentiate active from inactive fault zones. However, older faults that do not reach the surface can also be active; therefore, to address the limitations, we have combined tectonic geomorphological mapping with the seismological, geological, geodetic, and earthquake centroid moment tensor (CMT) solutions data. The first segment of the study utilizes satellite imagery to produce the best quality tectonic geomorphological maps. The second part of the study evaluates the site response parameters such as fundamental frequency (f0), H/V amplitude (A0), and soft sediment thickness (H) by acquiring, processing, and interpreting ambient noise data within the urban settlements of Taxila city. The results reveal that the study area is part of the compressional bend formed by the fault interactions between the Tarbela and the Jhelum fault zones. The mapped faults are mainly ~ NE–SW-trending oblique reverse faults that show a component of a sinistral strike-slip sense of movement. Our conceptual modeling illustrated by 3D cartoons shows that fault restraining bend structural configuration explains the unusual topographic highs such as Margala Hills, suggesting significant sinistral strike-slip motion along the mapped faults. The ambient noise data show a variable f0, A0 and soft sediment thickness, thus attesting to the site’s potential susceptibility to amplification in a significant earthquake, which poses a severe threat to the growing urbanization and population in the region. The findings from the study provide a platform for a detailed analysis of early earthquake hazards and disaster forecasting.
AB - Mapping active tectonic features remains a critical step in understanding earthquake hazards and producing reliable and scientifically robust maps. The mapping is often combined with seismological, geological, geodetic, and structural datasets to improve the overall quality of the maps. However, site response analysis is usually not connected with a typical active tectonic mapping exercise, which is a significant problem in improving earthquake hazard mapping. The motivation of the present study is to demonstrate the robustness of methodology where mapping of active tectonic features is combined with the site response analysis, thus mapping the earthquake sources and the seismic amplification potential of the region. Initially, tectonic geomorphological mapping was done by manually tracing the evidence of faulting, including the topographic breaks, earthquake ruptures, ridge crests, deflected streams, triangular facets, and so on. The cross-cutting relationships between the faults and the Holocene sedimentary deposits differentiate active from inactive fault zones. However, older faults that do not reach the surface can also be active; therefore, to address the limitations, we have combined tectonic geomorphological mapping with the seismological, geological, geodetic, and earthquake centroid moment tensor (CMT) solutions data. The first segment of the study utilizes satellite imagery to produce the best quality tectonic geomorphological maps. The second part of the study evaluates the site response parameters such as fundamental frequency (f0), H/V amplitude (A0), and soft sediment thickness (H) by acquiring, processing, and interpreting ambient noise data within the urban settlements of Taxila city. The results reveal that the study area is part of the compressional bend formed by the fault interactions between the Tarbela and the Jhelum fault zones. The mapped faults are mainly ~ NE–SW-trending oblique reverse faults that show a component of a sinistral strike-slip sense of movement. Our conceptual modeling illustrated by 3D cartoons shows that fault restraining bend structural configuration explains the unusual topographic highs such as Margala Hills, suggesting significant sinistral strike-slip motion along the mapped faults. The ambient noise data show a variable f0, A0 and soft sediment thickness, thus attesting to the site’s potential susceptibility to amplification in a significant earthquake, which poses a severe threat to the growing urbanization and population in the region. The findings from the study provide a platform for a detailed analysis of early earthquake hazards and disaster forecasting.
KW - Earthquake hazards
KW - Pakistan
KW - Site amplification
KW - Tectonic geomorphology
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UR - https://www.mendeley.com/catalogue/b1fb27d6-f37e-38c8-a0e4-fd7f25cb0055/
U2 - 10.1007/s40808-022-01542-z
DO - 10.1007/s40808-022-01542-z
M3 - Article
AN - SCOPUS:85139086661
SN - 2363-6203
VL - 9
SP - 1029
EP - 1050
JO - Modeling Earth Systems and Environment
JF - Modeling Earth Systems and Environment
IS - 1
ER -