Abstract Records of near‐fault ground motions from recent surface‐breaking earthquakes are characterized by large (> a few m/s), long‐period (a few seconds) ground velocity pulses, which may pose significant hazard for tall buildings and large infrastructures. Yet, the generation mechanism is not well understood. Here, using spontaneous rupture simulations, we examine the origin of large velocity pulses observed during the 2016 Mw7.0 Kumamoto (Japan) earthquake. We show that near‐fault waveform data as well as seismologically estimated moment and radiated energy can be well reproduced by a relatively simple model with uniform along‐strike pre‐stress and frictional properties. Our results suggest that large, long‐period ground velocities are caused by the dynamic interaction of propagating rupture and the Earth's surface, which is enhanced by reflected waves from the boundaries of low‐velocity layers. Such a generic mechanism suggests that large, long‐period ground motion is a common occurrence in near‐fault regions during surface‐breaking, strike‐slip earthquakes.

Earthquakes are a very frequent phenomenon, especially in the territory of Indonesia with a lot of compression pressure from the Eurasian and Indian Ocean tectonic plates. The influence of volcanism activity and the southern part of the Java subduction pathway triggers the formation of faults in Java, one of which is the Lembang fault. How is the geological history process structurally and the calculation of the maximum peak ground acceleration (PGA) to determine the characteristics of the Lembang fault? In this study, the focus is on a literature review with descriptive methods with the aim of collecting reference data information on studies to find out more about the characteristics of the Lembang fault. Based on the results of the literacy study that was collected and the interpretation of the structure that has been carried out, it can be stated that the characteristics of the Lembang fault are very complex through six sections. The majority are normal faults with strike-slip fault variations in several parts. The maximum peak ground acceleration probabilistic earthquake analysis on the Lembang fault depends on the distance and trajectory of the fault and the source of the earthquake and is on the type of soft or hard rock formation. Areas that have the highest maximum ground movement acceleration are in the North and East Bandung areas.

On 28 March 2025, a devastating M 7.7 earthquake struck Myanmar along the right-lateral strike-slip Sagaing fault, followed by an M 6.7 aftershock twelve minutes later. This study presents a comprehensive assessment of the earthquake’s effects through recorded strong ground motions, macroseismic intensity observations, secondary hazards including liquefaction, and remote sensing-based damage detection. The supershear rupture spanned ∼460 km, with pronounced fault directivity effects resulting in high peak ground acceleration values of up to 0.57g recorded for the horizontal components and macroseismic intensities reaching modified Mercalli intensity = X in nearby cities. Analysis of acceleration time series and Fourier amplitude spectra at nearby recording stations revealed significant near-field effects and spectral exceedances over Myanmar National building code design levels, particularly in the short-period range, affecting mostly low-rise structures. Secondary hazard evaluation indicates widespread liquefaction, especially near the Irrawaddy River, supported by correlations between cumulative absolute velocity and liquefaction probability maps. Remote sensing analysis using multitemporal Advanced Land Observation Satellite-2 Synthetic Aperture Radar (SAR) coherence data identified severe building and road damage in urban centers. A differential coherence method, coupled with urban masking and OpenStreetMap road data, enabled spatial quantification of damage, revealing over 39,000 km of roads and 306  km2 of buildings with moderate-to-heavy damage. The results provide critical insight into the earthquake’s impact and demonstrate the joint evaluation of ground-motion analysis and SAR-based damage mapping for rapid seismic response.

On 23 April 2025, a Mw 6.3 earthquake struck the Sea of Marmara near the Kumburgaz segment of the North Anatolian Fault (NAF), triggering over 500 aftershocks within 15 days. This study presents a rapid assessment of the event through aftershock relocation using double-difference technique, full moment tensor inversion of the mainshock, and ground motion analysis. The mainshock exhibited a strike-slip mechanism at a depth of 6 km with a significant non-double-couple component (40%). The aftershocks mostly occurred east of the mainshock, primarily within 10 km depth. Shakemaps derived from ground motion recordings highlight peak ground accelerations exceeding 210 cm/s2 east of the mainshock in western Istanbul and Modified Mercalli Intensities reaching level 6. The ground motion prediction equation developed for the region slightly underestimated the peak ground motions in short-period pseudo-spectral acceleration (PSA) and peak ground acceleration (PGA). Comparison with Turkish seismic design codes revealed that short-period PSA reached code limits in some stations, raising concerns for structural resilience especially in older buildings in those areas.

Earthquake rupture propagation speed is an essential source factor that largely controls hazard and risk. However, measuring rupture speeds of natural earthquakes is often challenging and ambiguous. Near-fault seismic waveforms (recorded within several km) are believed to have high capability for resolving rupture process. In this study, we probe the feasibility of using near-fault data signatures to directly infer rupture speeds in continental strike-slip earthquakes. To thoroughly understand near-fault features, we synthesize the near-fault seismic waves for kinematic source models on a strike-slip fault under different rupture speeds in a 3D medium. We identify the dependence of velocity waveform and particle motion on rupture speed in both amplitude and shape. In addition, we compare our results with the analytical solution with steady-state constant rupture speed. The discrepancies between the kinematic model and the analytical model indicate the contribution of radiation from different configurations. With inspecting the near-fault dataset of eight M>7 strike-slip earthquakes, we find that instead of dealing with the velocity waveforms with multiple high-frequency spikes, the features of the particle motion shape are easier to identify. Then we apply the particle-motion-based criterion to identify signatures associated with supershear, subshear, and other complexities such as multiple rupture fronts and initial-stage rupture phase. Our study highlights the further application of near-fault seismic data in studying earthquake sources.