## 1 Introduction
This approach has proven particularly useful in densely populated urban areas and regions with moderate seismic activity, where obtaining traditional seismic data can be limited [14]. Another innovative aspect is the application of three-dimensional (3D) models that allow for a more accurate representation of the spatial variability of soil response to earthquakes. These models, which integrate geomorphological, geotechnical, and geophysical data, have been essential in improving seismic risk assessment at the local level, as demonstrated by studies conducted in Italy and France [15]. Additionally, the incorporation of Geographic Information Systems (GISs) has facilitated the management and visualization of large volumes of data, enabling the creation of more detailed and accessible microzonation maps for use in urban planning and decision-making [16]. Seismic microzonation in complex soils, such as highly plastic clays, sand dunes, and other unconventional soils, has presented additional challenges that have driven improvements in study and analysis methodologies. In the Cavezzo region of northern Italy, a detailed microzonation was conducted that addressed the spatial variability of soil amplification due to complex geological conditions, including highly plastic clays and sand deposits. This interdisciplinary study integrated geotechnical, geophysical, and geomorphological data into a pseudo-3D model, allowing for the assessment of seismic risks in heterogeneous soils [15]. Similarly, in the city of Nice, France, a repeatable methodology for seismic microzonation was developed which included the analysis of deep clay soils and their behavior under seismic loading. This approach, which combined equivalent linear simulations with empirical data, enabled the identification of zones of high seismic amplification [16]. Meanwhile, the microzonation carried out in the Guwahati area of India highlighted the complexity of working with sand dunes, where studies based on uniform hazard spectra (UHS) integrated both local amplification effects and particular geological conditions, significantly improving structural safety in these areas [17]. Other works related to studies of regions with special soil characteristics can be found in [18; 19; 20]. Chile, located in one of the most seismically active zones in the world, has been a pioneer in the implementation of seismic microzonation studies to mitigate seismic risk. In the northern part of the country, in the cities of Arica and Iquique, a detailed microzonation study based on geophysical methods was conducted which identifiedareas more susceptible to soil movement amplification. This study contributed to the understanding of local seismic response and its comparison with the records of the 2014 Iquique earthquake [21]. Similarly, in the cities of Talca and Curico, located in central Chile, an extensive analysis was carried out using the Horizontal-to-Vertical Spectral Ratio (HVSR) of microtremors which correlated variations in soil resonance frequency with the damage observed after the 2010 Maule earthquake. This study highlighted the importance of considering local geological conditions to improve the accuracy of microzonation maps in complex geological contexts [22]. Additionally, in Vina del Mar, another study employed geophysical techniques involving surface waves and gravimetry to characterize the effects of seismic amplification in an area with a high concentration of damage to medium-rise buildings during the 2010 earthquake, emphasizing the influence of bedrock shape on soil amplification [23]. In particular, the city of Concon, Chile, located opposite the subduction zone of the Nazca Plate (Figure 1a), has its urban area largely situated on a dune deposit (Figure 1b), which still requires detailed dynamic characterization studies. This is especially relevant given the significant development of real estate projects in recent years, including a substantial number of high-rise buildings (Figure 1c,d).