SUBSURFACE STRUCTURE MODELING OF THE KAMCHATKA MONOGENETIC VOLCANIC FIELD (KMVF) USING GRAVITY AND MAGNETIC DATA

• Main Author: Alifna, Riyandra
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86267
• Institution: Institut Teknologi Bandung

Monogenetic volcanoes are a unique type of volcano, characterized by small eruption volumes and short eruption histories. The Kamchatka region contains a Monogenetic Volcanic Field (MVF) distributed around the Klyuchevskaya Volcanic Group (KVG). In Kamchatka, interactions between the Pacific and Eurasian plates trigger significant tectonic and volcanic activity. This study focuses on the phenomenon of crustal thinning associated with the formation of the MVF, where magma sporadically rises from the Earth's mantle to the surface. To model the subsurface structure, the authors used satellite gravity data from GGMPlus and magnetic data from EMAG2. The data processing involved Bouguer and terrain corrections on the gravity disturbance data to produce the Complete Bouguer Anomaly (CBA) and reduction to the pole (RTP) on the magnetic data to eliminate the influence of Earth's magnetic field. The analysis results show that the mantle's density and susceptibility range between 2.99 – 3.4 g/cm³ and 0.000001 – 0.0055 cgs, respectively, while the Earth's crust has a density of 2.72 – 2.76 g/cm³ and a susceptibility of 0.000004 – 0.060355 cgs. The 2D modeling reveals the presence of a magma chamber, magma flow, and variations in the Moho boundary, ranging from 26 km to 35 km in depth. The most significant crustal thinning is detected at a depth of 26 km beneath the MVF. This study provides new insights into the volcanic dynamics in Kamchatka and its implications for interpreting tectonic and volcanic activities in subduction zones. These findings may serve as a reference for similar studies in other volcanic regions.