Mustafa Softa

Deformation of glacier–bedrock systems provides evidence of slope adjustment before catastrophic failure. In a post-event assessment, we investigate the 26 August 2026 Langtang rock–ice failure in Nepal using NASA-ISRO Synthetic Aperture Radar (NISAR) observations to relate pre-event displacement to rock–ice interaction and valley confinement. Seven ascending line-of-sight (LOS) intervals characterize temporal change, while the final pre-event ascending–descending pair (P4) provides east–west and vertical displacement estimates. P4 spans 24-day windows ending on 19 and 16 August 2026. Relative to the surrounding terrain, median eastward and vertical displacements are +24.85 and −19.03 mm within the sampled possible detachment mapped by the United Nations Satellite Centre (UNOSAT), compared with +41.05 and +33.12 mm in the neighboring LOS deformation area. Opposing vertical tendencies and local east–west contrasts indicate differential movement across the rock–ice system. A positive LOS cluster lies 1.393 km from the possible detachment boundary and retains 78.8% of its connected area at coherence ≥ 0.70. The ascending record shows a positive pre-event contrast, a negative event-spanning contrast and a mixed post-event field. Together, these observations underpin a geological model in which oblique sliding increases loading at neighboring ice–bedrock contacts, promotes uplift and westward deflection, and transfers loading toward a valley constriction. We interpret this sequence as south to north, counter-clockwise adjustment accompanying differential sliding. The model connects the measured deformation pattern to structural weakness, changing glacial support and topographic confinement, providing a geological explanation for pre-event rock–ice adjustment within the source to valley hazard cascade.

Topographic evolution, particularly in extensional tectonic regimes, stems from fault activity and crust–mantle heterogeneity, both of which coordinate long‐term rock uplift. Understanding how surface topography records the interaction between fault activity and deep lithospheric processes is essential for explaining the extension of continental regions. In this study, Moho variations were adopted as a core element to examine landscape evolution along the Sındırgı Segment in Western Anatolia through a multimodal analysis of geomorphic indices, drainage‐network metrics, knickpoint distributions and the inversion of river longitudinal profiles. Morphometric parameters and normalized channel steepness showed along‐strike segmentation and spatially variable uplift patterns. and Gilbert metrics indicated uneven drainage‐divide behaviour, namely, the drainage system is still adjusting. River‐profile inversion showed that rock uplift got underway during the Late Pliocene and accelerated during the Early to Middle Pleistocene. This migration produced continual topographic markers preserved in the present‐day relief and knickpoints. Moho depth varied along the fault and matched the cumulative uplift and landscape segmentation. So upper‐crustal faulting alone is not enough to explain surface deformation and long‐wavelength topography. Note that the Moho data gave a regional‐scale lithospheric constraint; the observed relationship should only be interpreted as partial lithospheric modulation rather than direct causality. In conclusion, the Sındırgı Segment has not been shaped by a sole process. Instead, an intertwined system is active, in which fault‐controlled surface processes interact with deeper lithospheric heterogeneity. Spatially variable tectonic forcing, coupled with ongoing drainage adjustment within an active extensional setting, drives the landscape evolution.

The ~ 115 km long Sultandağı Fault forms the southern boundary of the Quaternary Afyon–Akşehir Graben in western Türkiye and represents a major active normal fault within the regional extensional regime. The Mw 6.5 Çay earthquake of 3 February 2002 produced surface rupture along its central segment, confirming its seismogenic capacity. This study presents the first detailed paleoseismological investigation of the Çay segment based on two trenches (Eskiköprü and Maltepe) excavated across faulted Holocene deposits. Stratigraphic and structural evidence documents five Holocene surface-rupturing earthquakes (E1–E5), including the historically documented 2002 Çay earthquake. Fourteen AMS radiocarbon samples (charcoal, bone, and carefully selected bulk organic sediments) were analyzed and modeled using a Bayesian approach in OxCal with stratigraphic constraints. Event ages and inter-event intervals were calculated at the 95.4% probability level (2σ), yielding millennial-scale recurrence behavior with uncertainty ranges extending up to ~ 1.59 kyr. The ~ 26 km cumulative surface rupture length observed during the 2002 earthquake corresponds to Mw ≈ 6.7 based on the Wells and Coppersmith (1994) normal-fault scaling relation, consistent with instrumental estimates. Measured vertical displacements (~ 20–25 cm) in trench exposures support moderate-magnitude (Mw 6–7) earthquake potential for single-segment ruptures. These results demonstrate repeated Holocene surface faulting with millennial recurrence intervals and confirm the capacity of the Çay segment to generate Mw ≥ 6.5 earthquakes. The findings provide quantitative input for time-dependent seismic hazard assessment within the Akşehir-Simav extensional system.

Earthquake Early Warning Systems (EEWS) represent one of the most effective technological solutions for mitigating the impacts of strong ground motion in seismically active regions. This study presents the design, implementation, and comprehensive evaluation of a real-time earthquake early warning system for Izmir-a region in Western Anatolia characterized by complex tectonic structures and high seismic hazard-using multi-station seismic acceleration data. The proposed framework integrates multi-threaded data acquisition, signal preprocessing, Min-Max normalization, and Euclidean distance-based similarity analysis to enable rapid detection of anomalous seismic patterns during the early P-wave phase. The system architecture consists of distributed sensor inputs, centralized real-time processing, similarity-based anomaly detection, and user-oriented visualization and alerting modules. The performance of the system was evaluated using both real and synthetic seismic datasets. Instrumental earthquake catalog from the 12 June 2017 Karaburun (Mw 6.2) and 30 October 2020 Samos (Mw 6.6) earthquakes demonstrate that the system can generate early warnings 18 s and 13 s prior to strong ground shaking, respectively. In addition, synthetic seismic scenarios were employed to assess system robustness under varying noise levels, station configurations, and signal conditions. The results indicate that the proposed framework maintains stable detection performance and low false-positive rates across diverse operational scenarios. The methodology emphasizes computational efficiency and inter-station waveform coherence analysis, providing a lightweight alternative to conventional magnitude-based approaches. By avoiding computationally intensive source inversion, the system achieves low-latency performance while preserving detection reliability. The proposed EEWS demonstrates strong generalization capability, scalability, and practical applicability for real-time deployment in earthquake-prone urban environments.

The Düziçi–İskenderun Fault Zone (DIFZ), located within the Amanos Mountains at the intersection of the African, Arabian, and Anatolian plates, is a structurally segmented and tectonically active component of the Eastern Anatolian Fault System (EAFS). This study integrates morphotectonic analysis, paleoseismological reevaluation, and limited field observations to elucidate the DIFZ’s role in deformation patterns and seismic potential. Morphotectonic analysis reveals spatial variability in uplift and erosion, with heightened tectonic activity in basins 4, 9–11, and 18, linked to structural complexities such as fault step-overs, bends, and abrupt topographic changes, suggesting localized strain concentration and elevated seismic potential. Field observations corroborate these findings, documenting triangular facets, V-shaped valleys, elongated basins, and fault scarps indicative of active crustal deformation. Paleoseismological raw data, taken from previously conducted studies at the Elbeyli (Düziçi) and Cona (Osmaniye) sites, identify three surface-rupturing events in the past ∼12 ka, with Bayesian-derived recurrence intervals of 4.3–4.7 kyr and interevent times of 0.3–9.1 kyr. Magnitude estimates (Mw ≤ 6.7) and slip rates (<1 mm/yr) classify the DIFZ as a moderately active fault zone. However, limited paleoseismic data from the Erzin and Payas segments constrain comprehensive hazard assessments. These findings highlight the DIFZ as a tectonic linkage between the EAFS, Dead Sea Fault, and Cyprus Arc, facilitating strain transfer across the southeastern Anatolian orogenic front. The integration of morphometric and paleoseismological approaches offers a refined framework for assessing seismic hazards in this tectonically complex region.

The Sındırgı earthquake sequence, with moment magnitudes of 6.1 on 10 August and 27 October 2025, respectively, occurred within the Simav Fault Zone in western Türkiye, rupturing nearby but structurally distinct fault segments. In this study, we combine Sentinel-1 InSAR time-series measurements with seismological data, geomorphic observations, and post-event field surveys to examine how deformation evolved between and after these events. InSAR results indicate coseismic line-of-sight displacements of 6–7 cm, followed by post-seismic deformation that persisted for months at 8–10 mm/yr. This behavior signifies that deformation continued well beyond the initial rupture. The estimated displacement does not align with a single fault plane. Instead, it corresponds to a network of early-mapped and previously unrecognized fault segments. Seismicity patterns and stress tensor inversions show that activity migrated spatially after 10 August and that the faulting mechanism altered before the second earthquake. When synthesized, observations indicate stress transfer within a modular, segmented fault system, thought to have been influenced by regional structural complexity. Field investigations after the October earthquake reported new surface cracks and fault traces, providing evidence of shallow deformation. The collected results indicate that post-seismic stress redistribution played a leading role in modulating the 2025 Sındırgı earthquake sequence.

Understanding how strain is transferred across the interior of tectonic plates is fundamental to quantifying lithospheric deformation. The Central Anatolia Transition Zone (CATZ), situated between the North and East Anatolian fault systems, provides a unique natural laboratory for investigating how continental deformation evolves from localized faulting to distributed shear. In this study, we integrate InSAR analysis with Global Navigation Satellite System (GNSS) velocity data, and stress tensor inversion with supporting gravity and seismic datasets to characterize the geometry, kinematics, and geodynamic significance of the CATZ. The combined geodetic and geophysical observations reveal that the CATZ is a persistent, left-lateral deformation corridor (i.e., elongated zone of Earth’s crust that accommodates movement where the landmass on the opposite side of a fault system moves to the left relative to an observer) accommodating ~4 mm/yr of shear between the oppositely moving eastern and western sectors of the Anatolian Plate. Spatial coherence among LiCSAR-derived shear patterns, GNSS velocity gradients, and regional stress-field rotations defines the CATZ as a crustal- to lithospheric-scale transition zone linking the strike-slip domains of central Anatolia with the subduction zones of the Hellenic and Cyprus arcs. Stress inversion analyses delineate four subzones with systematic kinematic transitions: compressional regimes in the north, extensional fields in the central domain, and complex compressional–transtensional deformation toward the south. The CATZ coincides with zones of variable Moho depth, crustal thickness, and inferred lithospheric tearing within the retreating African slab, indicating a deep-seated origin. Its S-shaped curvature and long-term evolution since the late Miocene reflect progressive coupling between upper-crustal faulting and deeper lithospheric reorganization. Recognition of the CATZ as a lithospheric-scale transition zone, rather than a discrete active fault, refines the current understanding of Anatolia’s kinematic framework. This study demonstrates the capability of integrated satellite geodesy and stress modeling to resolve diffuse intra-plate deformation, offering a transferable approach for delineating similar transition zones in other continental regions.

Bu çalışmada, Doğu Anadolu Fay Sistemi üzerinde gerçekleşen 6 Şubat 2023 Kahramanmaraş/Pazarcık (Mw: 7.7) depremine bağlı olarak Adıyaman ili Gölbaşı ilçesi ile Akçabel beldesi arasında net bir şekilde izlenen yüzey kırığı detaylı şekilde incelenmiştir. 1/25.000 ölçekli haritalama ve arazi çalışmalarıyla tespit edilen yüzey kırığı boyunca gelişen deformasyon sol yanal yer değiştirme miktarları ve düşey atım değerleri ile ölçülerek, fayın aletsel dönem deprem verilerine dayalı gerilme durumu analizi ile birlikte yorumlanmıştır. Yüzey kırığı üzerinde gerçekleştirilen çalışmalarda, (i) Adıyaman ili Gölbaşı ilçesi ile Akçabel beldesi arasında ~15 km haritalanan yüzey kırığının bu çalışmada tanımlanan Çakmak fayını izlediği, (ii) yüzey kırığının üzerinde gözlenen en büyük sol yanal yer değiştirmenin ve düşey atım değerlerinin Çakmak beldesi yakınlarında sırasıyla 425 cm ve 102 cm olarak ölçüldüğü, (iii) stres analizleri sonucunda fayın BKB-DKD yönlü gerilme kuvveti ve KKD-GGB yönlü sıkışma etkisi altında transtansiyonel tektonik rejim etkisinde deforme olduğu saptanmıştır.