The critical zone (CZ) represents the most-shallow subsurface, where the bio-, hydro-, and geospheres interact with anthropogenic activity. To characterize the thickness and lateral variations of the CZ, here we focus on the Eastern Betic Shear Zone (EBSZ), one of the most tectonically active regions in the Iberian Peninsula. Within the EBSZ, the Guadalentín Depression is a highly populated area with intensive agricultural activity, where the characterization of the CZ would provide valuable assets for land use management and seismic hazard assessments. To achieve this, we have conducted an interdisciplinary geophysical study along the eastern border of the Guadalentín Depression to characterize the CZ and the architecture of the shallow subsurface. The datasets used include Electrical Resistivity Tomography (ERT), first-arrival travel time seismic tomography, and multichannel analysis of surface waves (MASW). The geophysical datasets combined help to constrain the high-resolution structure of the subsurface and image active fault systems along four transects. The resulting geophysical models have allowed us to interpret the first ~150 m of the subsurface and has revealed: (i) the variable thickness of the CZ; (ii) the CZ relationship between the fault zone and topographic slope; and (iii) the differences in CZ thickness associated with the geological units. Our results provide a method for studying the shallow subsurface of active faults, complementing previous geological models based on paleo-seismological trenches, and can be used to improve the CZ assessment of tectonically active regions.

Porosity and permeability of the reservoir rocks can be calculated using digital rock physics. This technique is one of the fastest and effective ways to calculate the value of porosity and permeability based on rock sample images. The samples observed in this paper were gathered from the outcrop of oil-filled sandstone formation. The technology of digital rock physics allowed us to predict the physical properties, mainly porosity and permeability, in the outcrop sandstone samples. The digital image model displayed in the 2D and 3D images and the complexity of pore geometry as well. From the image, we develop the digital simulation to predict the value of porosity and permeability in the 3D samples. By applying this method, we have confirmed that the target area of this research is potential to be a reservoir, which is porous and clean.

Karakterisasi fitur-fitur geologi di dekat permukaan seperti distribusi ketebalan lapisan sedimen dan struktur geologi di dekat permukaan merupakan sesuatu yang menarik dan terus dipelajari untuk memahami kondisi secara lengkap di bawah permukaan. Meteode geofisika yang dapat digunakan karena keunggulannya untuk mengkarakterisasi target-target dangkal salah satunya adalah metode Multichannel Analysis of Surface Waves (MASW). Metode MASW adalah metode yang memanfaatkan sifat dispersif dari gelombang permukaan (surface waves) untuk memodelkan distribusi kecepatan gelombang geser pada setiap lapisan secara vertikal (Vs depth model). Metode MASW terdiri dari tiga tahap yaitu akuisisi, pengolahan data (processing), dan inversi. Pada paper ini, kami mendeskripsikan konsep/teori MASW secara umum dan aplikasinya untuk karakterisasi zona sesar dangkal pada target kedalaman sekitar 150 m. Penelitian ini didukung oleh data galian (trenches study) sebagai marker terhadap bidang sesar di daerah penelitian. berdasarkan studi daan hasil yang diperoleh dari paper ini, diharapkan aplikasi metode MASW di Indonesia akan semakin berkembang dan dapat digunakan dengan kepentingan yang semakin luas.

In CO2 storage technology, particularly in coal seams, necessitates specialized research into numerous critical factors that are equivalent to coal seam characteristics, including porosity, permeability, rock strength (UCS: uniaxial compressive strength), Poisson ratio, and brittleness. Rock properties of the coal seam are responsible for the CO2 storage capacity. In this study, we have core samples from the borehole and employed four well-logs (within and area ∼ 1000 m × 875 m) that drilled in the coal mining project located in South Sumatra Basin, Indonesia. The goal of this study is to describe the coal seam C strata in the sub-surface that have the potential to be utilized for underground CO2 storage. In this study, we identified coal seams C from low density and gamma rays from log response data. Then, we predict porosity values from data density, velocity (Vp andVs), UCS values, and BI using petrophysical and rock physics approaches. The result of this study shows that the distribution of top depth coal seam C varies in depth 19 to 225 m with the porosity 0.086-0.138. The value of UCS 1150 1299 Pa and brittleness index 0.531-0.569 that are associated with a characteristic coal with low to medium strength and medium brittleness. The results of this preliminary analysis revealed that the coal seam layer in this region has a high potential for CO2 storage in Sumatra, Indonesia.

The presence of dyes in wastewater is one of the main problems in wastewater treatment. Wastewater containing dyes can damage the ecosystem because it can block sunlight into the water and is often accompanied by toxic materials. This paper proposes an alternative method to decolorize dyes in water using CuO as a Fenton-like catalyst, especially for wastewater contaminated by methylene blue dye. The Fenton method is an advanced oxidation process method with a radical group of H₂O₂ acting as the primary decolorizing agent. By measuring the concentration using a UV-Vis spectrophotometer, we found that the proposed decolorization method effectively degraded the color of methylene blue. To understand the decolorization mechanism, we investigated the reaction kinetics of the decolorization process. We found that compared to the pseudo-first-order and second-order reaction kinetics models, the BMG model had higher accuracy and conformed to the color concentration degradation curve.