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On 8 July 2024, a magnitude 5.3 earthquake struck the province of Chiriquí in Panama, primarily impacting areas characterized by informal settlements and low-income neighborhoods. The earthquake was recorded by both the Panama Accelerographic Network and the Costa Rican Strong Motion Network, with accelerations exceeding 150 cm/s2. The National Civil Protection System (SINAPROC) reported damage to 24 residences and public infrastructure, including hospitals and schools. Despite the material damage, no fatalities were reported. The Ministry of Housing and Land Management (MIVIOT), the Ministry of Education (MEDUCA), and the Ministry of Social Development (MIDES) also participated in the assessment and response efforts. This report presents the measurements and damage observed during the event. [ABSTRACT FROM AUTHOR]

This article presents the findings of a study on the directionality effect observed in strong motion records. We set out to establish ratios between several seismic intensity measures that depend on sensor orientation (e.g., GMar, Larger) and others that are orientation-independent (e.g., RotDpp, GMRotDpp, and GMRotIpp), with the intention of proposing multiplicative correction factors. The analysis included an evaluation of the impact of site conditions, ground motion intensity, earthquake magnitude, and hypocentral distance on these ratios. Following a concise overview of the directionality effects and the associated intensity measures, the Costa Rican Strong Motion Database, comprising a total of 4199 horizontal accelerograms (two components), was employed to determine the correction factors. The analysis was carried out for 5% damped response spectra within the 0.01–5 s period range. The study focuses on orientation-independent intensity measures that are derived by combining the maximum values from the recorded motions. In the comprehensive analysis of the complete database, a trend was observed between these intensity measures and the magnitude of the earthquake along with the hypocentral distance. Specifically, records from earthquakes with greater magnitudes exhibited a lower maximum spectral response to the geometric mean of the response spectra of the as-recorded (ar) components ratio (RotD100/GMar), similar to records from earthquakes with larger hypocentral distances. Based on these findings, a proposal was put forth to estimate RotD100 values using GMar values. This ratio can prove useful in transforming data from previous seismic hazard studies, including those applied in many seismic codes, and in defining the maximum anticipated seismic intensity for design purposes in a more straightforward manner. [ABSTRACT FROM AUTHOR]