<![CDATA[Detecting fault gouge zones in poorly exposed fault systems is critical for understanding active deformation. The Menanga fault in Pesawaran (Lampung) revealed its activity during the 2021 swarm earthquake near Mt. Ratai at 1.5-4.5 km depth. Due to the limited exposure of the fault plane, geophysical imaging is applied to delineate subsurface structures. In this work, we conducted three survey lines using integrated geoelectric method and multi-frequency ground penetrating radar (50 MHz, 100 MHz, and 250 MHz) to investigate a clear image of Menanga fault zone. The electrical resistivity profiles revealed lateral discontinuities between relatively high-resistivity blocks separated by lower-to-intermediate resistivity materials, whereas the GPR profiles showed signal attenuation, chaotic radar facies, and discontinuous reflectors associated with structurally disturbed zones. Fault-related deformation zones were characterized by resistivity contrasts relative to adjacent high-resistivity blocks, together with low-amplitude, chaotic, and discontinuous GPR reflections. The clearest anomaly occurs at approximately 96 m offset along Line 1, where the subsurface discontinuity coincides with an exposed fault zone. Line 2 shows multiple fault-related discontinuities, whereas Line 3 exhibits an inferred deformation zone without clear surface exposure. Overall, the integration of electrical resistivity and multi-frequency GPR effectively delineates the shallow architecture of the Menanga Fault and provides geophysical evidence of fault-related deformation consistent with previous seismic and geomorphological studies.]]>
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