Arin Wildani, Sukir Maryanto, Didik R. Santoso, Hetty Triastuty
A study of volcanic tremors at Ijen volcano declared critical with an alert status in 2012, has been investigated. This mountain is located on the border of Banyuwangi and Bondowoso Regencies, East Java, Indonesia. At that time, volcanic tremors were recorded in large numbers or not as usual, accompanied by changes in the conditions of the Ijen crater lake. For example, an increase in temperature and the appearance of gas bubbles on the crater lake's surface. This study aims to identify the source of the volcanic tremors of the Ijen volcano. The historical method is used, which begins with data collection and interpretation of the symptoms of events that occurred in the past. The data obtained critically describes the truth of events or facts to help know what to do in the future. Then these facts are analyzed using particle motion to determine the orientation of the earthquake source based on the epicenter's angle, the incidence angle, and the types of waves that dominate volcanic earthquakes. For this reason, an amplitude plot of 3 wave components from the seismic record is carried out. The results showed that the orientation of the epicenter of the volcanic tremor of the Ijen volcano was towards the Ijen crater area. Meanwhile, the orientation of the hypocenter is towards the area below the center of the Ijen crater, about 1 km. In addition, the dominating wave is the horizontal S wave (SH) or the Love wave, which indicates that the single volcanic tremor of Mount Ijen occurred in a shallow area. Based on the fractal dimension value of the volcanic tremor, it strengthens the notion that the fluid-filling crack resonance causes the mechanism of the source of the volcanic earthquake. © 2023 WITPress. All rights reserved.
Department of Physics, Brawijaya University, East Java, Malang, 65145, Indonesia; Physics Education Study Program, Universitas Islam Madura, East Java, Pamekasan, 69351, Indonesia; Center for Volcanology and Geological Hazard Mitigation, West Java, Bandung, 40122, Indonesia