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Assessment of Ground Deformation and Landslide Susceptibility Using InSAR and Hypsometric Data in Jayapura City, Papua Anas, Nur Ayu; Hasudungan, Harsan Ingot; Indrajati, Rahmat; Yonas, Marcelino N.; Hutami, Harnanti Y.
JURNAL GEOCELEBES Vol. 9 No. 2: October 2025
Publisher : Departemen Geofisika, FMIPA - Universitas Hasanuddin, Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70561/geocelebes.v9i2.45404

Abstract

Ground deformation and landslides are major geohazards affecting Jayapura City, Papua, due to its active tectonic setting and steep topography. This study aims to assess the correlation between surface deformation and landslide susceptibility using a combination of Interferometric Synthetic Aperture Radar (InSAR) and hypsometric analysis. Sentinel-1A SAR data from ascending and descending tracks, combined with DEMNAS elevation data, were used to detect deformation patterns and evaluate geomorphological maturity through hypsometric parameters. The results reveal significant deformation patterns, including subsidence up to –0.77 m and uplift up to +0.25 m, predominantly concentrated in sub-watersheds Sw2, Sw3, and Sw4. Hypsometric analysis indicates that most sub-watersheds are in the mature geomorphological stage (HI between 0.476 and 0.495), except Sw14, which is classified as young (HI = 0.501). Validation with the landslide inventory further confirms this correlation: 75% of documented landslides occurred in areas of high deformation, while 25% were associated with moderate deformation, and none in low or stable zones. These findings provide essential insights for disaster risk reduction, highlighting priority areas for slope stabilization, land-use management, and early warning systems.
Regional Lineament Pattern and Morphotectonic Analysis: The Investigation of Geological Structures and Present-Time Relative Tectonic Activity in the Tin Granite Area of Belitung Island, Indonesia Hutami, Harnanti Yogaputri; Anas, Nur Ayu; Fattah, Erlangga Ibrahim
JURNAL GEOCELEBES Vol. 8 No. 1: April 2024
Publisher : Departemen Geofisika, FMIPA - Universitas Hasanuddin, Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20956/geocelebes.v8i1.33887

Abstract

Belitung Island is located on the East Coast of Sumatra and is the southernmost extension of the Southeast Asian granite belt. Despite the flat terrain of the island, numerous granite outcrops provide insight into the past tectonic activities that caused the uplift in the region. This study analyzes the current state of Belitung's tectonic activity by examining its morphotectonic index and lineament pattern. A National Digital Elevation Model (DEMNAS) dataset with a resolution of up to 8.1 m will be used to assess the geological patterns and relative tectonic activity from the surface. The relationship between the regional lineament system and morphotectonic quantification throughout the landforms of Belitung Island will also be considered. The modified Segmented Tracing Algorithm (m-STA) technique extracted the lineament features. The Index of Relative Active Tectonic (IATR) was calculated by averaging several morphotectonic indices, such as asymmetry factors (AF), stream-length index (SL), mountain-front sinuosity (Smf), and valley floor width-height ratio (VF) factors, to quantify the relative tectonic activity of the area. The combination of the two methods shows that Belitung is currently experiencing relatively weak tectonic activity compared to the past. This is supported by the surface appearance, which is mainly composed of lowlands. Several granite outcrops and highlands are aligned along the NW-SE and NE-SW directions, corresponding to the main geological structures in the area.
MINERALOGICAL ANALYSIS OF ROCK WEATHERING AND ITS INFLUENCE ON SLOPE FAILURE ALONG THE JAYAPURA CITY RING ROAD Karapa, Enos; Joni, Joni; Hartiningsih, Endang; Yonas, Marcelino Novryanto; Indrajati, Rahmat; Patabang, Djuarensi; Anas, Nur Ayu
Jurnal Ilmiah Ilmu Terapan Universitas Jambi Vol. 10 No. 2 (2026): Volume 10, Nomor 2, April 2026
Publisher : LPPM Universitas Jambi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/jiituj.v10i2.54453

Abstract

Slope failure along the Jayapura City Ring Road persisted despite shotcrete reinforcement, indicating that instability is not controlled solely by slope geometry or surface confinement. Field evidence points to weakening within foliated metamorphic rocks affected by tropical weathering, where mineral alteration progressively modifies the internal structure. This study examines how mineralogical transformations govern subsurface degradation and contribute to failure beneath reinforced slopes. A case study approach was applied using two representative samples (ST-01 and ST-02) obtained directly from the failure zone. Petrographic analysis of ~30 μm thin sections was conducted to evaluate mineral textures, fabric orientation, and alteration pathways. X-ray diffraction (XRD) was used to identify and semi-quantify the mineral phases, including albite, quartz, chlorite, muscovite, sericite, and magnetite. Subsurface conditions were assessed using ADMT resistivity profiling across a frequency range of 0.0001–10,000 Hz, reaching depths of approximately 300 m. The results indicate a mineralogical transition from a wollastonite–actinolite–chlorite assemblage in ST-01 to a chlorite–muscovite–sericite-dominated system in ST-02. The XRD data show a decrease in albite from ~19.74% to ~11.61%, while an unresolved fraction exceeding ~20% suggests the presence of poorly crystalline phases. Petrographic observations revealed that chlorite and sericite were concentrated along foliation and microfractures. The resistivity data identified a low-resistivity zone (10–20 Ωm) at depths of ~10–60 m, corresponding to altered and fluid-influenced domains. These findings indicate that weathering reduces cohesion along structurally controlled planes while preserving partial framework integrity, shifting the locus of failure to the subsurface beneath the shotcrete layer.