Soil response and behavior to megathrust earthquakes using the deterministic seismic hazard analysis (DSHA) method in Yogyakarta City

Natural disasters are events caused by natural phenomena, one of which is earthquakes. Earthquakes are among the natural disasters that may occur due to tectonic movements as well as volcanic activities such as volcanic eruptions. Tectonic earthquakes occur as a result of the movement of tectonic plates, where the Earth is seeking its point of stability. Yogyakarta City, located on the island of Java, is highly vulnerable to earthquakes because it lies within the Ring of Fire and is traversed by many fault zones that have the potential to generate earthquakes. Based on the results of seismic data processing, it was found that the soil in Yogyakarta City is classified as stiff soil, which is relatively soft and prone to liquefaction. The vibrations felt in Yogyakarta City are twice as strong compared to those at the earthquake source, and this is caused by differences in the resistance of the rock formations that make up Yogyakarta City and the earthquake source. The resonance effects on buildings are strongly perceived in structures with heights ranging from two to five stories compared to those on the ground surface.