ESTIMASI KEDALAMAN TITIK CURIE PADA DATA AEROMAGNETIK MENGGUNAKAN METODE ANALISIS SPEKTRAL DUA DIMENSI UNTUK MENGETAHUI STRUKTUR TERMAL REGIONAL (STUDI KASUS: AREA CASCADE RANGE, OREGON, AMERIKA SERIKAT)

• Main Author: Mahendra, Andriyansyahmi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55566
• Institution: Institut Teknologi Bandung

Curie point depth can be used for regional thermal structure investigation. This condition can be represented by the magnetic properties of magnetic minerals in the rock. In this study, a program to estimate the Curie point depth was developed using the two-dimensional (2D) spectral analysis method based on aeromagnetic data. Synthetic model testing was carried out as the initial stage to determine the effect of the calculation block in a research area on the Curie point depth estimation results. Based on the results of the program testing, the error percentage of the synthetic models with calculation blocks of 63.5 × 63.5 km2 with 50% overlap was found to be less than 1% so, program is considered to be successfull in determining the Curie point depth. The program was then applied to the aeromagnetic data in the Cascade Range Area, Oregon, United States. This area was chosen because it was considered to be able to show the corelation between volcanic activity and the Curie point depth. The 300 × 350 km2 area is divided into 143 blocks, with the area of 50 × 50 km2 and 50% overlap between blocks. The Curie point depth is obtained with the range of 2-12 km. The existence of volcanoes and hydrothermal systems is represented by the shallow Curie point depth, while outside this area the Curie point depth is deeper. The values of geothermal gradient and heat flow is later calculated from the Curie point depth and are at their highest in areas where volcanoes and hydrothermal systems are found and lower values are found in areas where there is no evidence of volcanoes or hydrothermal systems. The calculated values are respectively 34.73 °C/km - 157.50 °C/km for geothermal gradient and 55.57 mW/m2 - 245.71 mW/m2 for heat flow.