# Current tectonic deformation of the Sulaiman Range (Pakistan) with InSAR

François Jouanne, Lea Pousse-Beltran, Marie-Pierre Doin, Pascale Bascou, Franck Thollard, Awais Ahmed

► To cite this version:

François Jouanne, Lea Pousse-Beltran, Marie-Pierre Doin, Pascale Bascou, Franck Thollard, et al.  
Current tectonic deformation of the Sulaiman Range (Pakistan) with InSAR. Geophysical Journal  
International, 2025, 240 (3), pp.2060-2075. 10.1093/gji/ggaf023. hal-04974048

HAL Id: hal-04974048

https://hal.science/hal-04974048v1

Submitted on 26 Mar 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Current tectonic deformation of the Sulaiman Range (Pakistan) with InSAR

François Jouanne,<fnref n="1" /> Lea Pousse-Beltran,<fnref n="1" /> Marie-Pierre Doin,<fnref n="1" /> Pascale Bascou,<fnref n="1" /> Franck Thollard<fnref n="1" /> and Awais Ahmed<fnref n="2" />

Accepted 2025 January 10. Received 2025 January 10; in original form 2024 July 29

## SUMMARY

In Pakistan, the relative displacement between the Indian and Eurasian plates is accompanied by a left-lateral transpression zone comprising the Chaman and Ghazaband faults and the Sulaiman Range. The current tectonic deformation of the Sulaiman Range is known only from some focal mechanisms and a few neotectonic studies. In this study, we propose an Interferometric Synthetic-Aperture Radar (InSAR) quantification of current tectonic deformation using the Sentinel-1 satellite. Velocity maps for the ascending and descending tracks enabled us to locate active faults affected by creep: the Harnaï and Kingri strike-slip faults, and the Gwal-Bagh thrust. We propose a numerical simulation that considers these faults as well as the level of detachment fold-and-thrust belt. Our results suggest the existence of out-of-sequence deformation along the Gwal-Bagh thrust, creep along the Harnaï and Kingri strike-slip faults, and slip along the décollement of the Sulaiman Range. The eastern part of the Sulaiman Range is characterized by a partitioning of the deformation with a left-lateral strike-slip along the N170° Kingri fault and an eastward thrust. In contrast, the western part is characterized by north-south compressive deformation associated with right lateral strike-slip on the Harnaï N120° fault. Modelling of the coseismic deformation of the 2021 October 21 earthquake shows that this earthquake occurred on a fault with a ramp geometry, but affected by a strike-slip motion.

**Key words:** Radar interferometry; Seismic cycle; Asia.

## INTRODUCTION

The relative movement between the Indian and Eurasian plates is, to the south of the western Himalayan syntaxaxis, accommodated by a wide, left-lateral transpression zone made of a series of left-lateral strike-slip faults in the west (west to east Chaman and Ghazaband faults) and fold and thrust belts (Sulaiman Range, Kirthar) (Wellman 1966; Jadoon et al. 1999; Lawrence & Yeats 1979; Farah et al. 1984; Saad et al. 1997; Szeliga et al. 2012). On this border, the Sulaiman Range is a puzzling and poorly known fold and thrust belt, approximately 200 km long and 200 km wide.

The arcuate shape of the Sulaiman Range is especially challenging to understand because their distributed internal deformation is not consistent with a rigid translation at the level of detachment, as has been demonstrated for the Potwar Plateau and the Salt Range (Meyer et al. 2024). Two décollement levels, at a depth of approximately 15 km and the other shallow, led to the formation of a passive roof duplex (Jadoon et al. 2019). The arcuate fold and thrust belt are accompanied by right and left lateral, approximately north-south, strike-slip, or shearing on their western and eastern sides, respectively. Converge rates estimated from balanced cross-sections or

geomorphology (Jadoon et al. 1994, 2019) agree, pointing to a shortening of approximately 15 mm yr⁻<fnref n="1" /> from 20 Myr.

Thus, the distribution of the deformation only interpreted from geological cross-section, geomorphological mapping and focal mechanism, is inferred to be particularly complex in space, but also along the vertical direction, with two possible décollement levels as shown on Fig. 2 documented by seismic profiles and boreholes. However, no Global Navigation Satellite System (GNSS) networks are available in the Sulaiman Range to document spatially the current deformation, which would contribute to constraining the geometry and slip at the depths of the active structures.

Here, we provide, for the first time, a deformation mapping of the Sulaiman Range using the Interferometric Synthetic-Aperture Radar (InSAR) technique for Sentinel-1 acquisitions, although a priori north-south shortening is unfavourable for the application of this technique, we can detect the existence of localized slip along active faults and quantify the vertical component of current deformation. We use all the Sentinel-1 data acquired over 6 yr from 2015.0 to 2021.0 on ascending and descending tracks to quantify the ground velocity map along the line of sight (LOS). We use the New Small Baseline (NSBAS) software (Doin et al. 2011, 2015;

© The Author(s) 2025. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

<footnote n="1">¹ISTerre, CNRS, Université Grenoble Alpes, Université Savoie Mont Blanc, IRD, Université Gustave Eiffel, F-38000 Grenoble, France. Email: *Francois.Jouanne@univ-smb.fr*</footnote>

<footnote n="2">²Geoscience Advance Research Laboratories, Geological Survey of Pakistan, H8/1 Islamabad, Postal code 9013100-2, Pakistan</footnote>
<figure><img src="image_2.png" /></figure>

**Figure 1.** CMT focal mechanisms in the studied area for 0–20 km depth illustrating the occurrence of senestral strike-slip along the Chaman fault, eastward thrust east of 70°E, and strike-slips in the eastern part of Sulaiman Range illustrating strain partitioning and southward thrust in the western part of Sulaiman Range. The focal mechanism of the 2021 October 06 M<sub>w</sub> 5.9 earthquake is indicated in red and the 2008 Ziarat earthquake sequence in blue. Sentinel 1 tracks processed in this study are indicated by rectangles. The location of Fig. 3 is indicated by a rectangle. The inset shows the location of the study area.

Mathey *et al. 2022*) to process SAR data and obtain displacement time-series, which have already been shown to successfully quantify interseismic deformation at a continental scale (Daout *et al. 2018*; Thollard *et al. 2021*; Lemrabet *et al. 2023*). Two previous multi-temporal InSAR studies have been published in this area along the western boundary of the Indian and Eurasian plates; however, their primary focus is on the Chaman Fault (Fattahi *et al. 2015*; Fattahi & Amelung 2016; Barnhart 2017; Dalaison *et al. 2021*).

We also calculated the coseismic interferograms of a moderate-magnitude earthquake that occurred on 2021 October 7 (M<sub>w</sub> 5.9). Where possible, a numerical simulation was performed to better characterize the functioning (kinematics and geometry) of active faults in the study area.

## Geological setting

In eastern Sulaiman Range, fold and thrust belt is affected by north-south strike-slip faults, such as the Kingri active fault (Rowlands 1978; Humayon *et al. 1991*; Bernard *et al. 2000*; Khan *et al. 2019*; Fig. 1), which accompanies southward thrusting of the central and western Sulaiman Range. The eastern part of the Sulaiman Range (Fig. 1) is an example of partitioning of the deformation with active eastward thrusting along the most external thrust (Khan *et al. 2019*) and, in an internal position, strike-slip along a fault parallel to the thrust. To the north of the Sulaiman Range, the Gwal-Bagh and the Ghazaband-Zhob thrusts (Figs 1 and 2) mark the thrusting

of ophiolites and the ophiolitic mélange of the Upper Cretaceous or Triassic to Upper Cretaceous. The basal décollement of the Sulaiman Range is probably formed by different layers in the northern part of the Sulaiman Range. North of the Gwal-Bagh thrust (Khan *et al. 2007*), the décollement would be at the base of ophiolitic formation; south of this thrust, the décollement may be formed by Eocambrian evaporates, such as in the Potwar Basin-Salt Ranges or in the Kithar Range or by sedimentary layers in ductile conditions considering the thickness of the deformed sedimentary cover (more than 15 km, Davis & Lillie 1994); and in the frontal area, the décollement may be in the lower Triassic shales as found near the Kingri fault. The existence of a secondary more superficial décollement in the Upper Cretaceous explains the formation of a passive roof duplex (Fig. 2; Jadoon *et al. 2019*). Balanced cross-sections in eastern Sulaiman Range (Jadoon *et al. 2019*) suggest a shortening of 122 km since 6 ± 2 Ma, which implies a shortening rate of 15–30 mm yr⁻¹. However, in the eastern part of the Sulaiman Range, this same estimate is found with the 10 km shortening of the Sakhi Sarwar fault-bend fold since ~555 ka, giving 18 mm yr⁻¹. The same estimate of a shortening rate of 18 mm yr⁻¹ is also determined by an NS-balanced cross-section across the Sulaiman Range, with a shortening of 378 km during the last 21 Ma (Jadoon *et al. 1994*). West of the frontal structure of the eastern Sulaiman Range, the Kingri left-lateral strike-slip fault is active, as indicated by the observation of the fault in Quaternary deposits and its seismicity (Rowlands 1978; Quittmeyer *et al. 1984* and Fig. 1).
<figure><img src="image_3.png" /><figcaption>**Figure 2.** Geological cross-sections adapted from Jadoon & Zaib (2018) (locations on Fig. 1). Q: recent, P-g: Pleistocene–Oligocene molasse sediments: m: Miocene to Oligocene sandstone, g: Oligocene shales, g-e: Oligocene–middle Eocene, < e: Lower Eocene, pal: Palaeocene, Cr s: Cretaceous sandstone, Cr: Cretaceous, J: Jurassic, T: Trias and older and oph: ophiolites.</figcaption></figure>

and truncated drainage patterns (Rowlands 1978; Jadoon et al. 2019).

Two models have been proposed to explain the formation of this arcuate mountain range: the displacement of the Katawas block (Fig. 1), a block bounded by the Chaman fault and the Gwal–Bagh thrust zone (Haq & Davis 1997; Siddiqui & Jadoon 2013), or a gravitational engine as suggested by Copley (2012) and Reynolds et al. (2015) for the current deformation of Sulaiman Range.

## Current deformation

The Centroid-Moment-Tensor (CMT) focal mechanisms (Dziewonski et al. 1981; Ekström et al. 2012) for the period of 2015–2022 (Fig. 1) illustrate the existence of distributed deformation. These focal mechanisms correspond to ruptures on localized ramps above the décollement (depths < 15–20 km) or ruptures along strike-slip faults parallel to the directions of thrusts and folds, illustrating the partitioning of deformation. Focal mechanisms (Fig. 1) also illustrate the difference between the western part of the Sulaiman Range, west of 69°E, formed by a succession of southward thrusts and the eastern part, east of 69°E, where eastward thrusts and north–south folds are associated. Further west, the focal mechanisms clearly show the existence of ruptures along the Chaman strike-slip fault.

In recent years, one large earthquake $M_w$ 7.1 in 1997 and one seismic sequences in 2008 involving earthquakes of magnitude $M_w$ > 6 have affected the study region.

Thanks to a study combining seismological and InSAR data (Nissen et al. 2016), the 1997 $M_w$ 7.1 earthquake is found to be an earthquake doublet with a first rupture on a reverse fault (Fig. 3) with an $M_w$ 7.0 and another rupture on a second reverse fault located 50 km from the first with an $M_w$ 6.8, while a rupture affects a secondary fault with a magnitude of $M_w$ 6.0.

The 2008 October 28 earthquake sequence with a doublet of $M_w$ 6.4 earthquakes (MonaLisa 2010) preceded by an earthquake of

<figure><img src="image_4.png" /><figcaption>**Figure 3.** Faults activated during the 1997 earthquake and the 2008 earthquakes sequence (Pezzo et al. 2014; Nissen et al. 2016). The location of Fig. 3 is shown in Fig. 1.</figcaption></figure>
<table><caption>**Table 1:** Time-series duration for each track.</caption><thead><tr><th>Track</th><th>First date</th><th>Last date</th><th>Number of images</th><th>Number of interferograms</th></tr></thead><tbody><tr><td>A071</td><td>2015 January 14</td><td>2020 December 25</td><td>137</td><td>478</td></tr><tr><td>A042</td><td>2015 January 07</td><td>2020 December 30</td><td>133</td><td>589</td></tr><tr><td>D005</td><td>2015 February 15</td><td>2020 December 21</td><td>123</td><td>401</td></tr><tr><td>D078</td><td>2016 January 10</td><td>2020 December 26</td><td>128</td><td>539</td></tr></tbody></table>

*Note.* Number of images and interferograms used in the time-series inversion. Interferogram network is displayed in Figs S1–S4 (Supporting Information).

magnitude 5.3 and followed by five earthquakes of magnitudes between 4.8 and 5.7 has been studied by InSAR (Pinel-Puysségur et al. 2014; Pezzo et al. 2014; Usman & Furuya 2015). Although these studies propose different faults to explain the coseismic deformation associated with this sequence, they all converge in proposing that this sequence corresponds to ruptures along shallow NW-SE-trending right-lateral faults and NE-SW-trending left-lateral faults, which therefore appear to be conjugate. Pinel-Puysségur et al. (2014) propose the existence of three faults two trending left-lateral faults and one right-lateral fault allow the rotation and extrusion of a small block bounded by these faults, whereas Pezzo et al. (2014) feature a combination of five strike-slip faults delimiting two rotating blocks with right-lateral NW-SE faults and minor left-lateral NE-SW or ENE-WSW faults (Fig. 3). Usman & Furuya (2015) propose a combination of five non-rectilinear faults delimiting a small block rotating on itself and extruded towards the west and conjugate strike-slip faults to the north and south of this block compatible respectively with an extrusion towards the west and the east.

## METHOD

We processed the InSAR data Sentinel 1A and B data along the D078, D005, A042 and A071 tracks (Table 1) using the NSBAS processing chain (Doin et al. 2011; Grandin 2015; Grandin et al. 2016; Thollard et al. 2021) based on the Repeat Orbit Interferometry Package software (Rosen et al. 2004). We used the Shuttle Radar Topography Mission model (Farr et al. 2007) for the image co-registration step, as explained by Doin et al. (2015). The interferogram network construction included interferograms of short temporal baselines (12 d), interferograms at 3, 6 and 12 months, and 1 and 2 yr, with the latter maintaining phase coherence owing to the arid climate of the region (Figs S1a, S2a, S3a and S4a, Supporting Information). The spectral diversity method described by Thollard et al. (2021) is also used. The atmospheric phase screen of the interferograms was corrected using the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-5 meteorological reanalysis (Hersbach et al. 2020) following the methodology described by Doin et al. (2009) and Jolivet et al. (2011). This stratified atmospheric phase screen was calculated using the geopotential heights of pressure levels, temperature and specific humidity provided by the ECMWF. The delay was first interpolated as a function of elevation at regularly spaced ERA-5 nodes (every 0.25). Then, for each pixel in the radar coordinates, we computed the delay using bilinear interpolation of the surrounding ERA-5 nodes. Finally, we obtained interferograms for eight looks, corresponding to 75 m in range and 125 m in azimuth. The interferograms were filtered by averaging 6 × 6 square sliding windows weighted by the spatial coherence. Finally, the interferograms were unwrapped using the coherence associated with the filter averaging process on complex

values to guide the unwrapped integration path (Doin et al. 2011; Grandin et al. 2012). The image fractions that were successfully unwrapped are shown in (Figs S1b, S2b, S3b and S4b, Supporting Information) as a function of time and temporal baseline. Timeseries inversion is described in Thollard et al. (2021), Ho Tong Minh & Ngo (2022), Ho Tong et al. (2022) and can detect and correct unwrapping errors following the López-Quiroz et al. (2009) method. An average LOS velocity map was computed using the phase-delay time series and pixel-by-pixel linear least-squares regression. This LOS velocity map, assuming that the displacements are a linear function of time, was used in the following section of the manuscript. It must be emphasized that during the study period (2015.0–2021.0), there were no earthquakes of magnitude greater than 5.5 in the study area; therefore, the earthquake of 2021 October 6 (location Fig. 1) studied separately did not affect the velocity maps. To quantify the time-series quality, the inversion was generated after several iterations, the mean-square residue map for the entire data set, a mean-square residue for each interferogram and for each date acquisition, as described by López-Quiroz et al. (2009). Additionally, we computed the number of interferograms and images used in the time-series inversion for each pixel (Figs S1c, S2c, S3c and S4c, Supporting Information), a proxy for temporal coherence, was computed as the norm of the average of all successive interferometric triplets (between 0 and 1; Thollard et al. 2021).

## DESCRIPTION OF INSAR QUALITY ASSESSMENT PRODUCTS

All quality indicators presented in the Supporting Information (Figs S1–S4) allowed us to distinguish between the two cases. In the first case, when the covered area was almost exclusively located in the Sulaiman Range and not in the foreland, the unwrapping fractions were satisfactory, even for the 2-yr interferograms (Figs S1 and S2, Supporting Information). In the second case, when a significant proportion of the study area was located in the foreland, the unwrapping rates were much low (Figs S3 and S4, Supporting Information). This might be due to strong differences in surface properties: on the one hand, in the Sulaiman Range, coherence and thus unwrapping is good due to the lack of vegetation; on the other hand, the foreland has poor coherence and limited unwrapping due to the existence of cultivated areas. Analysis of the number of images per pixel, number of interferograms per pixel, and rms disclosure maps showed that the Quaternary basins within or around the Sulaiman Range were associated with low numbers of interferograms per pixel and high rms, indicating that the velocities calculated for these areas were less well constrained. Outside these basins, the maps all showed the maximum number of interferograms per pixel and rms better than 0.75 mm yr⁻¹ for D078 (Fig. S1e, Supporting Information), of the order of 0.75 mm yr⁻¹ for A042 (Fig S2e, Supporting Information), D005 (Fig. S3e, Supporting Information) and 0.75 to 1.5 mm yr⁻¹ or more for A071 (Fig S4e, Supporting Information). Therefore, given the estimated velocities of −8 to 8 mm yr⁻¹ (Figs 5–8), these were statistically significant.

## RESULTS

### Quaternary basins

Both the ascending and descending tracks present areas characterized by positive velocities along the LOS, suggesting that these areas are undergoing active subsidence (QB in Figs 4–7) reaching 8 mm yr⁻¹. The identification of these areas with optical images allows for the establishment of a correspondence between subsidence
<figure><img src="image_5.png" /><figcaption>**Figure 4.** Velocities in the LOS direction obtained for the descending D078 track. QB: Quaternary basin. Light grey inset indicates the area used to simulate slip along the Gwal-Bagh thrust, medium grey inset indicates the area used to simulate slip along the Harnaï fault, whereas black inset indicates the area used to simulate slip along the Kingri fault. These velocities have been obtained for the 2015–2020 time span, before the 2021 Harnaï earthquake.</figcaption></figure>

and areas characterized by quaternary deposits that are often culti-
vated (Huang *et al.* 2016). These areas corresponded to lower num-
bers of interferograms per pixel than the adjacent areas and a higher
rms of up to 3 mm (Figs S1e, S2e, S3e and S4e, Supporting Informa-
tion). For the modelling described below, these areas were masked.
South of the Sulaiman Range, an area was observed with a positive
LOS in both the ascending and descending tracks (Figs 5 and 6),
which has been linked to the Sui gas field (28.65°N, 69.2°E) in ex-
ploitation since 1952, with an actual annual production of 8.5 Mm³.

Gwal-Bagh thrust

The velocity contrast on the Gwal-Bagh thrust zone is stronger in the descending track (D078 in Fig. 4) than that in the ascending track (A042 in Fig. 5). We interpret this as a regional velocity field with eastward displacement rates to the northwest of the Gwal-Bagh thrust, followed by the thrusting of a wide area northwest of the faults towards E-SE. The existence of strongly subsiding Quaternary basins masks part of the deformation (Figs 4 and 5). The Gwal-Bagh thrust zone is located internally in the Sulaiman Range. Therefore, it was an out-of-sequence deformation along this major thrust zone, which is an ancient ophiolitic suture, as illustrated in the geological sections (Fig. 2). However, this thrusts zone is not marked by instrumental seismicity (Fig. 1), with the exception of its western end. If this absence of instrumental seismicity could be indicative of the absence of strain accumulation or medium-large earthquakes, this fault would be characterized by the existence of low coupling. This mechanical behaviour can be explained by the nature of the rocks present along the ophiolite fault. It is therefore unclear whether this set of thrusts can produce strong magnitude earthquakes.

Western part of Sulaiman Range

As shown in Figs 1 and 2, the western part of the Sulaiman Range, west of 69°E, is characterized by a southward thrust along N100–N120° faults. Under these conditions, horizontal southward displacement with a western component can be assumed, as indicated by the difference between the velocity maps of the descending and ascending tracks (Figs 4 and 5). The western part of the Sulaiman Range approaches the satellite on the ascending track (Fig. 4) and moves away from it on the descending track (Fig. 5).

Harnaï fault

A localized change in velocity is observed on either side of the right-
lateral Harnaï fault (Figs 4 and 5). On the descending track (Fig. 4),
the compartment north of the fault moved towards the satellite,
whereas the compartment south of the fault moved away from the
satellite. On the ascending track (Fig. 5), the LOS direction is almost
perpendicular to the fault line, making the change in velocity on
either side of the fault impossible to observe. The observation of a
clear change in velocity direction on the descending track implied
the existence of a slip on the fault near the surface. The lack of
clear change in both side of the fault on the ascending track allow
to underline that this slip has a negligible vertical component and is
that the Harnaï fault is an active strike-slip fault affected by creep.

An earthquake of magnitude M<sub>w</sub> 5.9 occurred on 2021 October 6, 15 km of the M<sub>w</sub> 7.1 earthquake Harnaï (Figs 1 and 3), which occurred on 1997 February 27 (Nissen *et al.* 2016). This earthquake (red focal mechanism in Fig. 1) provides an opportunity to complete the knowledge of the active fault system highlighted by this large earthquake involving three fault planes (Fig. 3), according to
<figure><img src="image_6.png" /><figcaption>**Figure 5.** Velocities in the LOS direction obtained with the ascending A042 track. QB: Quaternary basin. Light grey inset indicates data used to simulate slip along the Gwal-Bagh thrust, whereas medium grey inset indicates the area used to simulate slip along the Harnaï fault.</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>**Figure 6.** Velocities in the LOS direction obtained for the descending D05 track. KF: Kingri fault. Inset indicates data used to simulate slip along the Kingri fault.</figcaption></figure>
<figure><img src="image_8.png" /><figcaption>**Figure 7.** Velocities in the LOS direction obtained for the ascending A071 track. Inset indicates data used to simulate slip along the Kingri fault.</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>**Figure 8.** Coseismic deformation of the 2021 October 6, earthquake obtained by the stack of four coseismic interferograms (A144: 2021 September 20/October 14, 2021 October 02/2021 October 14 and D078: 2021 August 27/2021 October 14, 2021 September 08/2021 October 14).</figcaption></figure>

Nissen *et al.* (2016). The coseismic deformation (Fig. 8) was estimated using ascending and descending data.

## Eastern part of Sulaiman Range

### Frontal area

The lack of coherence in the foreland of the Sulaiman Range does not allow for the quantification of relative velocities between the external Sulaiman Range and the Indian Plate. Localized slip along

the Kingri fault is difficult to measure using InSAR because of the N170° orientation of the fault. Nevertheless, we observed a localized displacement across the fault on the descending track (D05 in Fig. 6) that did not appear on the ascending track (A078 in Fig. 7) parallel to the fault. We can, therefore, conclude from these observations that the vertical component of displacement on this fault is minor and that the slip on this fault (Fig. 6) is probably purely horizontal and characterized by localized left-lateral strike-slip. The observation of localized velocity differences on both sides of the Kingri fault clearly illustrates the existence of creep along this fault.
## MODELLING OF CURRENT DEFORMATION

To perform the inversion, we sampled the InSAR data using the quad-tree method (Jónsson *et al.* 2002). Once this sampling was completed, we removed data with high standard deviations and data corresponding to Quaternary sedimentary basins that were found to be characterized by high subsidence, probably reflecting high compaction or pumping-induced subsidence (Huang *et al.* 2016).

We modelled the instantaneous velocities in the LOS geometry obtained by InSAR, considering dislocations whose geometries (orientation, dip and depth) were constrained by structural geology data. Thus, we considered the existence of a general décollement and localized thrusting or strike-slip faults between the surface and the décollement, in other words, we assume that the velocities reflect localized deformation along faults and along the detachment level and not volume deformation, for example with the formation of folds. Similarly, during inversion, we considered rakes that could vary between a minimum and maximum value compatible with the slip directions of the focal mechanisms and the structural geology data. In our model, we determined the slip on a fault using the steepest descent method (SDM) software (Wang *et al.* 2009, 2011, 2012). This software is based on an iterative algorithm used for constrained least-squares optimization. Curved faults can be used with this software, which is particularly appropriate in this case. This software also allows the determination of an offset between different data sets used to invert the fault slip. The upper limit of the slip must be provided as the rake range for the slip. Smoothing

<figure><img src="image_10.png" /><figcaption>**Figure 9.** Simulated slip rates along the décollement level (black arrows) of eastern Sulaiman Range and slip rate distribution along the Kingri left-lateral strike-slip fault illustrating the occurrence of creep along the northern part of the fault.</figcaption></figure>

<figure><img src="image_11.png" /><figcaption>**Figure 10.** Modelling of slip along the eastern Sulaiman Range basal décollement and along the Kingri strike-slip fault indicated by the black line, for descending (D005) track. Area on D005 track used for this simulation is indicated in Fig. 5. Obs: Observations, Mod: simulated velocities and Res: residuals.</figcaption></figure>
<figure><img src="image_12.png" /><figcaption>**Figure 11.** Predicted surface velocities, horizontal and vertical velocities estimated by our best model.</figcaption></figure>

<figure><img src="image_13.png" /><figcaption>**Figure 12.** Simulated slip rates along the basal detachment of western Sulaiman Range with location of the Harnaï fault. Slip rate distribution model along the Harnaï fault is also shown.</figcaption></figure>

can be applied to both stress drop and slip, we used the last option with a smoothing factor of 0.2 in this study.

Modelling of slip along the Kingri fault and along the eastern Sulaiman Range thrust

Examination of the focal mechanisms (Fig. 1) suggests strain partitioning with eastward slip in the eastern part of the Sulaiman Range and left-lateral strike-slip along the north–south faults in the more internal part of this region. The basal décollement of the Sulaiman Range (Fig. 2) is therefore unlikely to be affected by uniform slip, as significant slip variations can be expected on either side of the main strike-slip fault, the Kingri fault. The décollement extends under the whole thrust and fold belt, to the east up to the eastern envelope of folds and a depth at this boundary of 7.5 km, as shown in section C of Fig. 2, and a dip towards the west of 4°, as suggested by the cross-sections (Fig. 2). To determine the slip rates along these dislocations, we assumed rakes between 40° and 90°, as suggested by the focal mechanisms and the associated slip direction of the reverse type. Basal detachment was discretized using 10 × 10 km patches.

To model the slip along the Kingri fault, we assumed that the Kingri fault is vertical and present between the surface and basal décollement of the Sulaiman Range located at a depth of 12 km, that is, the depth of the décollement at the fault level. Therefore, we inverted the velocity field by assuming a discretized vertical fault with 2 × 2 km patches of purely left-lateral strike-slip (rake 0°). If we consider only the Kingri fault in our simulation, we obtained poor agreement between the observations and simulations, as shown in Fig. S6 in the Supporting Information, characterized by high residuals, and a simulation that does not consider the LOS velocities measured in ascending and descending acquisitions. Even near the Kingri fault, the measured velocities were poorly simulated. These results show that, we need to add a creeping basal décollement level to fit the observations.

Our best solution (Fig. 9) was obtained for a heterogeneous slip reaching 12 mm yr⁻¹ along the Kingri fault slip, showing the occurrence of creep along the northern part of the fault between the surface and 12 km depth, and another patch of creep in the southern part of the fault between 0 and 14 km depth. Along the basal
<table><caption>**Table 2.** Best solutions determined by BEAT for the two possible focal planes.</caption><thead><tr><th></th><th>Latitude</th><th>Longitude</th><th>Depth (km)</th><th>Dip (°)</th><th>Strike (*)</th><th>Length (km)</th><th>Width (km)</th><th>Slip (m)</th><th>Rake (°)</th><th>M<sub>w</sub></th></tr></thead><tbody><tr><td>Hyp. 1</td><td>30.0758</td><td>67.9075</td><td>6.2 ± 0.7</td><td>39.4 ± 5.9</td><td>327.6 ± 6.7</td><td>9.5 ± 1.2</td><td>10.4 ± 2.7</td><td>0.56 ± 0.089</td><td>162.0 ± 5.3</td><td>6.1</td></tr><tr><td>Hyp. 2</td><td>30.1043</td><td>67.9217</td><td>6.2 ± 0.6</td><td>78.4 ± 4</td><td>72.4 ± 4.5</td><td>9.3 ± 1.7</td><td>12.2 ± 2.8</td><td>0.61 ± 0.072</td><td>44.8 ± 6.7</td><td>6.17</td></tr></tbody></table>

*Note.* Solution hyp. 1 provides a better simulation of the measured coseismic displacements and is therefore considered the most likely.

<figure><img src="image_14.png" /><figcaption>**Figure 13.** Modelling of slip along the western Sulaiman Range basal décollement and along the Harnaï strike-slip fault. Obs: Observations, Mod: simulated velocities and Res: residuals for descending D78 track. Area on D078 track used for this simulation are indicated in Fig. 3.</figcaption></figure>

décollement, the dip slip reached 12 mm yr⁻¹ with a heterogeneous pattern, with the maximum slip along the northern and western borders of the model. Strike-slip occurs along the décollement near the intersection between the Kingri fault and the décollement level. This value is lower than the shortening rate of 18 mm yr⁻¹ deduced from balanced cross-sections (Jadoon et al. 2019) for the last 6 Ma. This difference suggests the existence of temporal variations in shortening rates between 6 Ma and the present day.

The differences between the observed and simulated data (Fig. 10, and Figs S7 and S8, Supporting Information) show a generally good agreement between the data and our final model, except for the northwestern part of the study, where residuals reaching 4 mm yr⁻¹

were observed, suggesting that other phenomena occurred in this area.

The slip along the décollement (Fig. 9) and the predicted surface horizontal velocity field by this model (Fig. 11) illustrate a strain partitioning with eastward velocities up to 3 mm yr⁻¹ in the external part of the Sulaiman Range, as shown by focal mechanisms (Fig. 1), and southeastward horizontal velocities reaching up to 15 mm yr⁻¹ west of the Kingri left-lateral strike-slip fault, as also shown by focal mechanisms (Fig. 1). The horizontal gradient of the velocity field indicates global compression of the Sulaiman Range with deformation partitioning conditioned by the Kingri fault with E-W compression east of the fault and NW-SE compression west of it.
<figure><img src="image_15.png" /><figcaption>**Figure 14.** Predicted surface velocities, horizontal and vertical velocities estimated by our best model.</figcaption></figure>

Modelling of slip along the Harnaï fault and along the Sulaiman Range décollement

The Western Sulaiman Range presents both reverse and right lateral strike-slip focal mechanisms (Fig. 1), suggesting both N-S shortening and right lateral strike-slip, in the direction of the Harnaï fault, N 120°. As shown in the cross-sections (Fig. 2), the décollement was at a depth of 9 km, dipping a few degrees to the north. If we only consider the Harnaï fault, we would not be able to model the velocities observed (Fig. S9, Supporting Information), so in our modelling we must also consider the existence of slip along the décollement level. It can be assumed that the slip along the décollement level changes on either side of the Harnaï fault. Therefore, for the modelling, we considered a discretized décollement with patches of 10 × 10 km, allowing the slip rake along the décollement to vary considerably from −140° to −40°, and considered a maximum slip rate of 15 mm yr⁻¹. We assumed that the Harnaï fault was purely strike-slip, with a dip that may not be purely vertical. The best solution for the dip of the Harnaï fault was obtained for a dip of 70° to the south. Our best model (Fig. 12) was associated with differences between the observed and simulated data (Fig. 13 and Fig. S10, Supporting Information), showing a generally good agreement between the data and our final model with residuals that do not suggest the existence of unmodelled sources of deformation, with the possible exception of the area to the northwest of the descending data used. Our best model shows that the Harnaï fault (Fig. 12) has a main creep zone between 3.5 and 11.5 km depth, with slip rates locally reaching 8 mm yr⁻¹. The slip rate field modelled along the décollement (Fig. 12) shows slip rates with changing directions on either side of the Harnaï fault, slip rates up to 15 mm yr⁻¹, and a gradient to the southwest of the study area compatible with strong shortening, as shown by the focal mechanisms (Fig. 1). The horizontal gradient of the predicted ground velocity field (Fig. 14) indicates global compression of the southwestern Sulaiman Range with localized deformation along the Harnaï fault.

Modelling of coseismic deformation of Harnaï earthquake

To obtain the geometry of the fault and the coseismic slip, we use the Bayesian Earthquake Analysis Tool (BEAT), developed by Vasyura-Bathke *et al.* (2020) based on the Python toolbox Pyrocko (Heimann *et al.* 2017). We use the BEAT package that implements the Sequential Monte Carlo sampling algorithm (Minson *et al.* 2013). Green's functions used are calculated from the AK135 earth model (Kennett *et al.* 1995) using PSGRN from Wang *et al.* 2006. We allowed all the fault parameters (Table 2) to be free (depth, rake, strike, location and slip), as initial values we adopt the location, depth, strike and dip of the focal mechanisms proposed by Shaukat *et al.* (2023). The modelling allows to propose two best solutions following the two initial geometries (Shaukat *et al.* 2023; Table 2) while Figs 15 and 16 show the agreement between the initial data and the final models. The first model (hyp. 1 in Table 2) appears to be statistically better, with a model data agreement (rmse) of 0.0090 m for ascending data and 0.0082 m for descending data, while the data agreement with the second model is 0.0091 m for ascending data and 0.0090 m for descending data. If we consider as the best model solution hyp. 1 (Fig. 15), which has a strike of N327°, a dip of 39° and a rake of 162°, then we can hypothesize that this earthquake occurred on a fault with a ramp geometry and a predominantly right lateral strike-slip component and therefore corresponds to the reactivation of a thrust formed during an earlier tectonic stage. This fault (Fig. 15), which runs in the same direction and direction as the Harnaï fault, is one of the faults that allowed the Sulaiman Range to move southwards.

DISCUSSION

The InSAR data show a significant velocity gradient across the Gwal-Bagh thrust zone (Figs 4 and 5) which suggests the existence of creep on this faults zone. The occurrence of this creep is probably
<figure><img src="image_16.png" /><figcaption>**Figure 15.** Observation and modelling of the 2021 October 06 Harnaï earthquake, geometry test of the first focal plane corresponding to the hyp. 1 (see Table 2).</figcaption></figure>

related to the nature of these thrusts which, as a former ophiolitic suture, probably has serpentine bodies, a lithology known to favour creep.

In the eastern Sulaiman Range, InSAR data (Figs 6 and 7) and focal mechanisms (Fig. 1) clearly show the existence of deformation partitioning with external eastward thrusting and active strike-slip behind the frontal zone along the Kingri fault. InSAR velocity modelling showed the existence of significant creep of up to 12 mm yr⁻¹ along the north–south Kingri fault (Fig. 9), with two creep zones between the surface and the basal décollement at a depth of 16 km. Numerical modelling of velocities in the eastern Sulaiman Range requires the introduction of a basal décollement. This presents a large heterogeneity of slip velocities mainly towards the east along the basal décollement; nevertheless, the innermost and deepest parts of this plane (Fig. 9), perhaps in the ductile condition, present significant slip velocities of 12 mm yr⁻¹, which is lower than the proposed shortening velocities of 18 mm yr⁻¹ by geological cross-section (Jadoon et al. 1994, 2019).

A comparison of the ascending and descending InSAR data revealed a marked change in velocity on either side of the right-lateral Harnaï fault (Figs 4 and 5). Slip modelling along this fault (Fig. 12) has pinpointed a creep zone between 3.5 and 11.5 km depth, while slip on the globally southward décollement changes on both

sides of this fault. In this region, we globally have a north–south compression shown not only by the predicted horizontal velocity field (Fig. 14) but also by focal mechanisms (Fig. 1), allowing the relative displacement between the Sulaiman Range and their foreland.

Northeast of this area, the 2021 earthquake near Harnaï (Figs 1, 15 and 17) probably occurred on a fault with a ramp geometry and a predominantly right lateral strike-slip component and therefore corresponds to the reactivation of a thrust formed during an earlier tectonic stage and could be an extension of the Harnaï fault.

This earthquake and the 1997 earthquakes sequence (Fig. 17), therefore, illustrate the current deformation, characterized as before by a deformation of the cover with ruptures located on ramps and flats and along strike-slip faults as the focal mechanisms also show (Figs 1, 3, 15 and 16). The co-existence of thrusting on the outside and unthrusting on the inside, as shown by these earthquakes, is also shown in the interseismic period with the association in the western part of the Sulaiman Range between a basal thrust and the Harnaï unthrusting fault and in the eastern part with slip along the basal thrust and slip along the Kingri strike-slip fault. The active deformation of the Sulaiman Range is therefore an example of deformation partitioning.
<figure><img src="image_17.png" /><figcaption>**Figure 16.** Observation and modelling of the 2021 October 06 Harnaï earthquake, geometry test of the second focal plane corresponding to the hyp. 2 (See Table 2).</figcaption></figure>

The InSAR measurements presented, the focal mechanisms, and the available sections converge then to describe the deformation of the Sulaiman Range as a cover deformation conditioned by a level of detachment plunging east–west and south–north by a few degrees, probably in the form of a trough. The present deformation showed slightly lower rates of shortening than those suggested by the geological sections since 6 Ma for eastern Sulaiman Range (Jadoon *et al. 1999*) or since 21 Ma for the central Sulaiman Range (Jadoon *et al. 1994*), these differences may reflect a recent slowdown in the shortening rate over the last 21 or 6 Ma. The other structures forming the western boundary of the Indian Plate absorbed a significant part of the relative displacement between the plates. The distribution of deformation along this plate boundary, estimated at 30–32 mm yr⁻¹, remains unclear; for example, the Chaman fault absorbs a third of the displacement along the western boundary of the Indian plate based on InSAR (Dalaison *et al. 2021*) and GPS data (Szeliga *et al. 2012*; Crupa *et al. 2017*) or all of it (30 mm yr⁻¹) based on geomorphic marker offsets (Ul-Hadi *et al. 2013*). Between latitudes 28.5°N and 33°N, the Sulaiman Ranges could accommodate approximately half of the displacement along the western boundary of the Indian Plate with transpressive left-lateral tectonics combining eastward thrusting, NS left-lateral strike-slip, and southward thrusting in the western half of the structure. Our study shows that GNSS data could make a major contribution to understanding the

ongoing deformation of the Sulaiman Range. The ongoing installation of permanent and episodic GNSS stations by the Geological Survey of Pakistan, with points installed both in the foreland and in the Sulaiman Range, so as to frame the active faults identified (Kingri and Harnaï faults, active thrust of the Sulaiman Range on their foreland), should provide in a few years a better understanding of the current deformation.

## CONCLUSION

Quantification of current deformation by InSAR in the study area showed the existence of significant LOS displacement rates of several mm yr⁻¹, well above the noise, associated with the Sulaiman Range, while this technique did not allow for the measurement of displacements in the foreland of this range. Locally, areas showing strong positive LOS displacements on both ascending and descending tracks are associated with Quaternary basins and are interpreted as reflecting the subsidence of these basins. A comparison of the descending and ascending data has shown the existence of ongoing deformation associated with the Gwal-Bagh thrust, a major fault in an internal position, and therefore out of sequence. Modelling of the InSAR data makes it possible to specify the deformation underway
<figure><img src="image_18.png" /><figcaption>**Figure 17.** Active faults in the Sulaiman Range identified by significant earthquakes since 1997 studied by InSAR and faults identified by our study and the 2022 M<sub>w</sub> 6.0 earthquake (Dalal *et al.* 2024).</figcaption></figure>

in the eastern and western parts of the Sulaiman Range. In the east-
ern Sulaiman Range, the deformation is partitioned as also shown
by focal mechanisms with eastward thrusting along the décollement
level associated with a left-lateral strike-slip along the Kingri fault
affected by a creep reaching 12 mm yr⁻¹. In the western Sulaiman
Range, the décollement level is affected by a southward slip while
the right lateral NW-SE Harnaï fault (slip reaching 8 mm yr⁻¹)
accompanies the southward displacement of the Sulaiman Range.
Coseismic displacement modelling of the 2021 October 07 earth-
quake, located northwest of the Harnaï fault, allowed us to propose
that this earthquake took place along the geographical extension of
the Harnaï fault.

SUPPORTING INFORMATION

Supplementary data are available at *GJIRAS* online.

Please note: Oxford University Press is not responsible for the con-
tent or functionality of any supporting materials supplied by the
authors. Any queries (other than missing material) should be di-
rected to the corresponding author for the paper.

DATA AVAILABILITY

Sentinel 1 data are available on the ESA website, and atmospheric
corrections use the ECMWF ERA-5 meteorological re-analysis data

available from the Copernicus website. SDM software is available
on the GFZ website. The velocity maps (in Tiff format) and samples
of these maps (in text format) used in this study are available online:
Jouanne (2023). Current deformation of the Sulaiman Range. https:
//doi.org/10.5281/zenodo.8340476

REFERENCES

Barnhart, W.D. 2017. Fault creep rates of the Chaman fault (Afghanistan and Pakistan) inferred from InSAR, *J. geophys. Res.: Solid Earth*, **122**(1), 372–386.

Bernard, M., Shen-Tu, B., Hold, W.E. & Davis, D.M., 2000. Kinematics of active deformation in the sulaiman lobe and range, Pakistan, *J. geophys. Res.: Solid Earth*, **105**(B6), 13253–13279.

Copley, A., 2012. The formation of mountain range curvature by gravita-
tional spreading, *Earth planet. Sci. Lett.*, **351-352**, 208–214.

Crupa, W.E., Khan, S.D., Huang, J., Khan, A.S. & Kasi, A. 2017. Active tectonic deformation of the western Indian plate boundary: a case study from the Chaman fault system, *J. Asian Earth Sci.*, **147**, 452–468.

Dalaison, M., Jolivet, R., van Rijlsingen, E.M. & Michel, S. 2021. The interplay between seismic and aseismic slip along the Chaman fault illuminated by InSAR, *J. geophys. Res.: Solid Earth*, **126**, e2021JB021935, doi:10.1029/2021JB021935.

Dalal, P., Senapati, B. & Kundu, B., 2024, Co-seismic surface displacement of the June 21, 2022 Mw6 Khōst, Afghanistan earthquake from InSAR observations, *Geod. Geodyn.*, **15**(3), 201–208.
Daout, S., Doin, M.P., Peltzer, G., Lasserre, C., Socquet, A., Volat, M. & Sudhaus, H., 2018. Strain partitioning and present day fault kinematics in NW Tibet from Envisat SAR interferometry, *J. geophys. Res.: Solid Earth*, **123**(3), 2462–2483.

Davis, D.M. & Lillie, R.J., 1994. Changing mechanical response during continental collision (active examples from the foreland thrust belts of Pakistan, *J. Struct. Geol.*, **16**(1), 21–34.

Doin, M.-P., Lasserre, C., Peltzer, G., Cavalié, O. & Doubre, C. 2009. Correc-
tions of stratified tropospheric delays in SAR interferometry: validation
with global atmospheric models. *Journal of Applied Geophysics*, **69**(1),
35–50.

Doin, M., et al. 2011. Presentation of the small baseline NSBAS processing chain on a case example: the Etna deformation monitoring from 2003 to 2010 using Envisat data, In *Proceedings of the Fringe 2011 Workshop*, Frascati, Italy, 19–23 September 2011.

Doin, M.P., Twardzik, C., Ducret, G., Lasserre, C., Guillaso, S. & Jianbao, S. 2015. InSAR measurement of the deformation around Siling Co Lake: inferences on the lower crust viscosity in central Tibet, *J. geophys. Res. Solid Earth*, **120**, 120, 5290–5310.

Dziewonski, A.M., Chou, T.-A. & Woodhouse, J.H. 1981, Determination of earthquake source parameters from waveform data for studies of global and regional seismicity, *J. geophys. Res.*, **86**, 2825–2852.

Ekström, G., Nettles, M. & Dziewonski, A.M. 2012, The global CMT project 2004-2010: centroid-moment tensors for 13,017 earthquakes, *Phys. Earth planet. Inter.*, **200-201**, 1–9.

Farah, A., Lawrence, R.D. & Dejong, K.A., 1984, An overview of the tec-
tonics of Pakistan, in *Marine Geology and Oceanography of Arabian Sea and Coastal Pakistan*, eds., Haq, B.U. & Milliman, J.D., Van Nostrand
Reinhold, pp. 161–176.

Farr, T.G. et al. 2007 The shuttle radar topography mission, *Rev. Geophys.*, **45**, 1–33.

Fattahi, H. & Amelung, A. 2016. InSAR observations of strain accumulation and fault creep along the Chaman fault system, Pakistan and Afghanistan, *Geophys. Res. Lett.*, **43**, 8399–8406.

Fattahi, H., Amelung, F., Chaussard, E. & Wdowinski, S. 2015. Coseismic and postseismic deformation due to the 2007 M5.5 Ghazaband fault earthquake, *Balochistan, Pakistan, Geophys. Res. Lett.*, **42**(9), 3305–3312.

Grandin, R., Doin, M.P., Bollinger, L., Pinel-Puysségur, B., Ducret, G., Jolivet, R. & Sapkota, S.N. 2012. Long-term growth of the Himalaya inferred from interseismic InSAR measurement, *Geology*, **40**, 1059–1062.

Grandin, R., Klein, E., Métois, M. & Vigny, C. 2016. Three-dimensional displacement field of the 2015 Mw8.3 Illapel earthquake (Chile) from across-and along-track Sentinel-1 TOPS interferometry, *Geophys. Res. Lett.*, **43**, 2552–2561.

Grandin, R. 2015. Interferometric processing of SLC Sentinel-1 TOPS data, In *Proceedings of the FRINGE'15, Advances in the Science and Applications of SAR Interferometry and Sentinel-1 InSAR Workshop*, Frascati, Italy, 23–27 March 2015. https://proceedings.esa.int/files/116.pdf

Haq, S.S.B. & Davis, D.M., 1997. Oblique convergence and the lobate moutain belts of western Pakistan, *Geology*, **25**, 1, 23–26.

Heimann, S. et al. 2017. *Pyrocko—An Open-source Seismology Toolbox and Library*. V 0.3. GFZ Data Services.

Hersbach, H., Bell, B., Berrisford, P., Dahlgren, P., Horanyi, A. & Nicolas, J.P., 2020, The ERA5 Global reanalysis: a detailed record of the global weather and climate from 1950 onward, in *Q J R Meteorol Soc.* **146**, p. 1999–2049.

Ho Tong Minh, D. & Ngo, Y.N. 2022. Compressed SAR interferometry in the big data era, *Remote Sens.*, **14**(2), 390, doi:10.3390/rs14020390.

Ho Tong, M.D., Hanssen, R., Doin, M.-P. & Pathier, E., 2022. *Advanced Methods for Time-series InSAR*. John Wiley Sons, Ltd, ch. 5, pp. 125–153. [Online]. Available:https://onlinelibrary.wiley.com/doi/abs/10.1002/ 9781119986843.ch5

Huang, J. et al. 2016 Study of subsidence and earthquake swarms in the western Pakistan, *Remote Sens.*, **8**(11), 956, doi:10.3390/rs8110956.

Humayon, M., Lillie, R.J. & Lawrence, R.D., 1991. Structural interpretation of the Eastern Sulaiman Fold Belt and Foredeep, Pakistan, *Tectonics*, **10**(2), 299–324.

Jadoon, I.A.K. & Zaib, M.O. 2018. *Tectonic Map of Sulaiman Fold Belt: 1:500,000 Scale*. COMSATS University Islamabad (Abbottabad Campus), Pakistan.

Jadoon, I.A.K., Lawrence, R.D. & Lillie, R.J., 1994. Seismic data, geometry, evolution, and shortening in the active Sulaiman fold-and-thrust belt of Pakistan, southwest of the Himalayas, *AAPG Bull.*, **78**(5), 758–774.

Jadoon, I.A., Frisch, W., Jaswal, T. & Kemal, A. 1999. Triangle zone in the Himalayan foreland, north Pakistan., *Geol. Soc. Am. Spec. Pap.* **82**, 275–286. https://proceedings.esa.int/files/116.pdf

Jadoon, S.U.R., Ding, L., Jadoon, I., Baral, U., Qasim, M. & Idrees, M.. 2019. Interpretation of the Eastern Sulaiman fold-and-thrust belt, Pakistan: a passive roof duplex, *J. Struct. Geol.*, **126**, 231–244.

Jolivet, R., Grandin, R., Lasserre, C., Doin, M.-P. & Peltzer, G. 2011. Systematic InSAR tropospheric phase delay corrections from global meteorological reanalysis data, *Geophys. Res. Lett.*, **38**(17), n/a, doi:10.1029/2011GL048757.

Jónsson, S., Zebker, H., Segall, P. & Amelung, F., 2002. Fault slip distri-
bution of the 1999 Mw7.1 hector mine, California earthquake, estimated
fromsatellite radar and GPS measurements, *Bull. seism. Soc. Am.*, **92**(4),
1377–1389.

Jouanne, F. 2023. Current deformation of the Sulaiman Range.

Kennett, B.L.N., Engdahl, E.R. & Buland, R. 1995. Constraints on seismic velocities in the Earth from traveltimes, *Geophys. J Int.*, **122**, 108–124.

Khan, N. 2019, Tectonic geomorphology and structural architecture of east-
ern Sulaiman Fold Thrust Belt (SFTB) and adjacent Sulaiman Foredeep
(SF), northwest Pakistan, *Geomorphology*, **343**, 145–167.

Khan, S.D., Mahmood, K. & Casey, J.F. 2007. Mapping of Muslim Bagh ophiolite complex (Pakistan) using new remote sensing, and field data, *J. Asian Earth Sci.*, **30**(2), 333–343.

Lawrence, R.D. & Yeats, R.S., 1979. *Geological Reconnaissance of the Chaman fault in Pakistan*. In: Farah, A. & DeJong, K.A.(Eds.), Geodynamics of Pakistan, pp. 351–357.

Lemrabet, L., Doin, M.P., Lasserre, C. & Durand, P. 2023. Referencing of continental-scale InSAR-derived velocity fields: case study of the eastern Tibetan plateau, *J. geophys. Res.: Solid Earth*, **128**(7), e2022JB026251, doi:10.1029/2022JB026251.

López-Quiroz, P., Doin, M.-P., Tupin, F., Briole, P. & Nicolas, J.-M. 2009. Time series analysis of Mexico City subsidence constrained by radar interferometry, *J. appl. Geophys.*, **69**(1), 1–15.

Mathey, M., Doin, M.-P., André, P., Walpersdorf, A., Baize, S. & Sue, C. 2022. Spatial heterogeneity of uplift pattern in the Western European Alps revealed by InSAR time-series analysis, *Geophys. Res. Lett.*, **49**, e2021GL095744, doi:10.1029/2021GL095744.

Meyer, P., Jouanne, F., Doin, M.P., Ahmed, A., Awan, A.A. & Mug-
nier, J.L., 2024 Present-day quantification of seismic coupling along
the décollement level beneath the Potwar Plateau region in Pakistan western
Himalaya, *E.P.S.L*, **637**, 118723, doi:10.1016/j.epsl.2024.118723.

Minson, S.E., Simons, M. & Beck, J.L., 2013 Bayesian inversion for finite fault earthquake source models I—Theory and algorithm, *Geophys. J. Int.*, **194**(3), 1701–1726.

MonaLisa & Jan, M.Q., 2010. Geoseismological study of the Ziarat (Balochistan) earthquake (doublet?) of 28 October 2008, *Curr. Sci.*, **98**, 1, 50–57.

Nissen, E., Elliott, J.R., Sloan, R.A., Craig, T.J., Funning, G.J., Hutko, A. & Wright, T.J. 2016. Limitations of rupture forecasting exposed by instantaneously triggered earthquake doublet, *Nat. Geosci.*, **9**(4), 330–336.

Pezzo, G., Bancori, J.P.M., Atroz, S., Antonioli, A. & Salvi, S. 2014 Deformation of the western Indian plate boundary: insights from differential and multi-aperture InSAR data inversion for the 2008 Baluchistan (Western Pakistan) seismic sequence, *Geophys. J. Int.*, **198**, 25–39.

Pinel-Puysségur, B., Grandin, R., Bollinger, L. & Baudry, C. 2014 Multifaulting in a tectonic syntaxaxis revealed by InSAR: the case of the Ziarat earthquake sequence (Pakistan), *J. geophys. Res.: Solid Earth*, **119**, 5838–5854.

Quittmeyer, R.C., Kafka, A.L. & Armbruster, J.G., 1984. Focal mechanisms and depths of earthquakes in central Pakistan: a tectonic interpretation, *J. geophys. Res.: Solid Earth*, **89**(B4), 2459–2470.
Reynolds, K., Copley, A. & Hussain, E., 2015 Evolution and dynamics of a fold-thrust belt: the Sulaiman Range of Pakistan, *Geophys. J. Int.*, **201**(2), 683–710.

Rosen, P.A., Hensley, S., Peltzer, G. & Simons, M. 2004 Updated repeat orbit interferometry package released, *EOS Trans. Am. geophys. Un.*, **85**, 47, doi:10.1029/2004EO050004.

Rowlands, D., 1978. The structure and seismicity of a portion of the southern Sulaiman Range Pakistan, *Tectonophysics*, **51**(1–2), 41–56.

Saad, S., Haq, B. & Davis, D.M. 1997 Oblique convergence and the lobate mountain belts of western Pakistan, *Geology*, **25**(1), 23–26.

Shaukat, A.Z., Tahir, M., Iqbal, T., Iqbal, T. & Shah, M.A. 2023. Seismotectonic analysis of the 7 October 2021 Mw 5.9 Harnai earthquake, Pakistan, *Bull. seism. Soc. Am.*, **113**, 636–647.

Siddiqui, N.K. & Jadoon, I.A. & *Search and Discovery Article* 2013. Indo-Eurasian plate collision and the evolution of Pakistan Makran Microplate, Pishin-Katawaz Fault Block and the Porsali Trough. https://www.searchanddiscovery.com/pdfz/documents/2013/30265siddiqui/ndx_siddiqui.pdf.html

Szeliga, W., Bilham, R., Kakar, D.M. & Lodi, S.H. 2012. Interseismic strain accumulation along the western boundary of the Indian subcontinent, *J. geophys. Res.: Solid Earth*, **117**(B08404), doi:10.1029/2011JB008822.

Thollard, F. et al. 2021. FLATSIM: the ForM@Ter LArge-scale multi-temporal Sentinel-1 InterferoMetry service, *Remote Sens.*, **13**(18), 3734, doi:10.3390/rs13183734.

Ul-Hadi, S., Khan, S.D., Owen, L.A. & Khan, A.S. 2013. Geomorphic response to an active transpressive regime: a case study along the Chaman

strike-slip fault, Western Pakistan, *Earth Surf. Processes Landforms*, **38**(3), 250–264.

Usman, M. & Furuya, M., 2015, Complex faulting in the Quetta Syntaxis: fault source modeling of the October 28, 2008 earthquake sequence in Baluchistan, Pakistan, based on ALOS/PALSAR InSAR data, *Earth Planets Space*, **67**, 142, doi:10.1186/s40623-015-0303-2.

Vasyura-Bathke, H., et al. 2020. The Bayesian earthquake analysis tool, *Seismol. Res. Lett.*, **91**(2A), 1003–1018.

Wang, L., Wang, R., Roth, F., Enescu, B., Hainzl, S. & Ergintav, S. 2009, Afterslip and viscoelastic relaxation following the 1999 M 7.4 Izmit earthquake from GPS measurements, *Geophys. J. Int.*, **178**(3), 1220–1237.

Wang, R., Lorenzo-Martín, F. & Roth, F. 2006. PSGRN /PSCMP—a new code for calculating co- and post-seismic deformation, geoid and gravity changes based on the viscoelastic-gravitational dislocation theory, *Comput. Geosci. Geosci.*, **32**(4), 527–541.

Wang, R., Parolai, S., Ge, M., Jin, M., Walter, T.R. & Zschau, J. 2012. The 2011 Mw 9.0 Tohoku earthquake: comparison of GPS and strong-motion data, *Bull. seism. Soc. Am.*, **103**, 1336–1347.

Wang, R., Schurr, B., Milkereit, C., Shao, Z., & Jin, M. 2011. An improved automatic scheme for empirical baseline correction of digital strong-motion records, *Bull. seism. Soc. Am.*, **101**(5), 2029–2044.

Wellman, H.N., 1966 Active wrench faults of Iran, Afghanistan and Pakistan, *Geol. Rundschau*, **55**, 716–735.