The 6.1 magnitude earthquake on April 10, 2021, with its hypocenter near the southern coast of Malang Regency, Indonesia, caused extensive damage, including in the Turen District. Turen District is a densely populated area and home to one of the state’s defense and security equipment manufacturers, Pindad Company. This study aims to determine the site effect (v s30 ) using the microtremor method and the ground motion using the Probabilistic Seismic Hazard Analysis (PSHA) method in Turen. The ground motion parameters, represented as Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) at periods of 0.2, 1, and 3 seconds, are triggered by various earthquake sources, including subduction and fault earthquakes, as well as background earthquakes, using the Ground Motion Prediction Equation (GMPE). Microtremor measurements were conducted at 54 points across the research site. The results show the v s30 ranges from 352.81 to 553.92 m/s, which is dominated by very dense soil criteria. The PGAs, SA0.2, 1.0, and 3.0 vary between 0.72 - 0.79 g , 1.72 - 1.89 g , 0.92 - 1.02 g , and 0.27 - 0.29 g, respectively. The damage caused by the 6.1 magnitude earthquake occurred in areas with relatively low v s30 values. This study also proposes a local seismic design expected to assist local governments in earthquake disaster mitigation and serve as a reference for building construction.
Ilham et al. (Sun,) studied this question.