## 4 Results
### Dimensionality Analysis: Induction Arrows  
In Figure 7, based on the Parkinson convention, low-resistivity zones (conductive zones) are represented by red arrows for the real component of induction and blue arrows for the imaginary component. At a frequency of 317 Hz, as shown in Figure 7a, the induction arrows point towards conductive zones from the northwest (NW) to the southeast (SE). The stations ACH04, ACH05, and C3 show arrows pointing from the southwest (SW) to the northeast (NE) in the northwest part, while the stations ACH06, ACH07, ACH08, ACH09, ACH10, ACH11, and C4 display arrows pointing from NE to SW, indicating a conductive zone along the NW-SE direction. Similarly, the stations C5 and KEMA point to conductive zones towards the SE and NW, respectively. Additionally, the ACH02 station shows a conductive zone towards the SE, and the SARP station indicates a conductive zone towards the NW. In the southeast part, the stations D1, D4, D7, D8, TANG, and GEM show arrows pointing from NE to SW, indicating a conductive zone along the NW-SE direction. The presence of the Aceh Fault extending along the NW-SE direction is identified as the conductive zones extending from NW to SW based on the references [7; 58], which is shown by the red pointing arrows. However, some stations, such as ACH01, C1, and MBMG, show a different direction from the NW-SE path, which points towards SW. This is due to the influence of conductivity from the sea [59]. On the other hand, the induction arrows of the KAWA station point east (E), and are associated with the Batee Fault located in the southeast. Figure 6: Polar diagram for the frequencies of (**a**) 317 Hz, (**b**) 100 Hz, (**c**) 10 Hz, (**d**) 1 Hz, (**e**) 0.1 Hz, and (**f**) 0.05 Hz. The black triangle is the MT station, the red diagrams depict \(Z_{xx}\), and the black diagrams depict \(Z_{xy}\). Figure 7: Induction arrows for frequencies of (**a**) 317 Hz, (**b**) 100 Hz, (**c**) 10 Hz, (**d**) 1 Hz, (**e**) 0.1 Hz, and (**f**) 0.05 Hz in the different scale of induction arrows. The red arrows depict the real part of the tipper vector \(\mathbf{T}_{Re}\) and the black diagrams depict the imaginery part of tipper vector \(\mathbf{T}_{im}\) (using Parkinson convention, red arrows point to the conducting body). The A, B, C, D, and E (yellow circle) depict dominant conductive zones. At a frequency of 100 Hz, the pattern in Figure 7b is almost the same as at 317 Hz. The induction arrows generally point towards conductive zones extending from NW to SE. The direction of the induction arrows at each station remains the same, but some stations have longer length components of the induction arrows. The length of the induction arrows is determined by the amplitude of the real component. A larger real component is usually observed in coastal areas [59], as seen at the stations ACH01, C1, MBMG, and D9. At this frequency, some stations experience rotation. For instance, the C1 station changes direction from SW to W due to the influence of sea conductivity [59]. The MANE station experiences a shortening of the induction arrows, indicating a decrease in amplitude. This suggests that at a depth corresponding to the 100 Hz frequency, the conductivity effect of the nearby conductive zone is more influential than the sea conductivity effect. In Figure 7c, at a frequency of 10 Hz, the conductive zones are generally localized, indicated by the presence of conductive zones marked with dashed circles in areas A, B, C, D, and E. Conductive zone A is confirmed due to the presence of the Aceh Fault and the Seulimeum Fault on the geological map in Figure 1. Conductive zone B, consisting of the stations PIDIB, KEMA, and TANG, points to alluvial sediments with conductive resistivity ranging from 10 to 800 \(\Omega\)m on the geological map in Figure 1. Zone D indicates a conductive zone towards the SE, aligning with the direction of the Aceh Fault.