Since August 2016, central Italy has been struck by one of the most important seismic sequences ever recorded in the country. In this study, a strong‐motion data set, consisting of nearly 10,000 waveforms, has been analyzed to gather insights about the main features of ground motion, in terms of regional variability, shaking intensity, and near‐source effects. In particular, the shake maps from the three main events in the sequence have been calculated to evaluate the distribution of shaking at a regional scale, and a residual analysis has been performed, aimed at interpreting the strong‐motion parameters as functions of source distance, azimuth, and local site conditions. Particular attention has been dedicated to near‐source effects (i.e., hanging wall/footwall, forward‐directivity, or fling‐step effects). Finally, ground‐motion intensities in the near‐source area have been discussed with respect to the values used for structural design. In general, the areas of maximum shaking appear to reflect, primarily, rupture complexity on the finite faults. Large ground‐motion variability is observed along the Apennine direction (northwest–southeast) that can be attributed to source‐directivity effects, especially evident in the case of small‐magnitude aftershocks. Amplifications are observed in correspondence to intramountain basins, fluvial valleys, and the loose deposits along the Adriatic coast. Near‐source ground motions exhibit hanging‐wall effects, forward‐directivity pulses, and permanent displacement.

On the night of February 6, 2023, a major earthquake struck Turkey and nearby Syria, whose moment magnitude (M) was estimated at 7.8 (or 7.7, depending on the data source). It started what can be considered a seismic sequence with thousands of recorded earthquakes with magnitude larger than two, including another M6.7 event (or 6.6) occurring shortly after, and one M7.5 (or 7.6) a day and a half later. The area in the south‐eastern part of Turkey hit by the sequence is considered, according to probabilistic models, one of the most hazardous in the wider region. This technical note aims at a preliminary illustration of some features of the shaking, deemed of earthquake engineering relevance. To this aim, it preliminarily analyzes the evolution of the sequence so far and the related ground motion intensity, as estimated from ShakeMap envelopes, then focuses on the largest magnitude event, for which a preliminary model of the source is available, while a supplementary report is provided for the other two events. Based on data available at the time of writing, it is found that the development of the sequence and the recorded ground motions are generally in agreement with available models, although some locations may have experienced peak ground accelerations larger than 1.0 g, and near‐source effects, determining pulse‐like ground motions, apparently occurred.

The availability of high‐quality waveforms recorded in epicentral areas of moderate‐to‐strong earthquakes is a key factor for investigating ground‐motion characteristics close to the seismic source. In this study, near‐source strong‐motion waveforms (named NESS1) were collected from worldwide public archives with the aim of building a flat file of high‐quality metadata and intensity measures (IMs) of engineering interest. Particular attention was paid to the retrieval of reliable information about event sources, such as geometries and rupture mechanisms that are necessary to model near‐source effects for engineering seismology and earthquake engineering applications. The accelerometric records are manually and uniformly processed, and the associated information is fully traceable. NESS1 consists of about 800 three‐component waveforms relative to 700 accelerometric stations, caused by 74 events with moment magnitude larger than 5.5 and hypocentral depth shallower than 40 km, with Joyner–Boore distance up to 140 km. Ground‐motion data were selected to have a maximum source‐to‐site distance within one fault length, defined through seismological scaling relations. About 40 records exhibit peak acceleration or peak velocity exceeding $1g$ or $120cm/s$, and they represent some of the largest ground motion ever recorded. Evidence of near‐source effects was recognized in the NESS1 dataset, such as velocity pulses, large vertical ground motions, directional and hanging‐wall amplifications and fling step. In particular, around 30% of the records was found to exhibit pulse‐like characteristics that are possibly due to forward rupture directivity.