Open AccessPreliminary Study of Probolinggo Active Fault in East Java Based on Gravity Method
Author(s) -
Juan Pandu Gya Nur Rochman,
Mohammad Singgih Purwanto,
Anik Hilyah,
F M. Haris Miftakhul,
Mohamad Setyo Ari Nuswantara,
Syafiatun Nuriyah
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/936/1/012025
Subject(s) - bouguer anomaly , geology , gravity anomaly , fault (geology) , gravitational field , lithology , acceleration , residual , geodesy , igneous rock , seismology , geophysics , free air gravity anomaly , petrology , geochemistry , physics , mathematics , algorithm , paleontology , classical mechanics , astronomy , oil field
The Gravity Method based on TOPEX satellite data is a one of geophysical method which from satellite observations. The gravity method investigate the gravitational field from one to another observation point. The principle of this method has the ability to distinguish the mass material density from its environment, so that the subsurface structure can be identified. In this research, gravity method is used to identify subsurface structures that are suspected of Probolinggo Fault and identify the rock lithology. From TOPEX we get free air anomaly and then applied the correction process to obtain Complete Bouguer Anomaly (CBA) value. The CBA value is processed interpolation to create CBA map, and then the map is filtered by butterworth to obtain regional and residual maps. The value of high gravity acceleration is 0.076 - 19.74 mGal indicating compact rocks. Meanwhile, based on the residual anomaly map, the value of smaller gravity acceleration is -0.92 - 0.9 mGal indicates lower compacting rocks with smaller mass. The gravity acceleration contrast on the residual anomaly, on the north side of fault line (0.12 mGal to 0.45 mGal) and on the south side (-0.92 mGal to -0.043 mGal), is interpreted as normal fault. Furthermore, 3D modelling shows density value less than 2 gr/cm 3 we can interpret as pyroclastic fall, in between 2 gr/cm 3 until 2.4 gr/cm 3 is sandstone and more than 2.4 gr/cm 3 is igneous rock such as andesit. 2D slicing modelling show presence the shear fault, so we can suspect this area have oblique fault with west-east direction.