Paleoseismic of the Walanae Fault Zone in the South Arm of Sulawesi, Indonesia

EasyChair Preprint 4068

Abstract

Walanae Fault is a major structure in the South Arm of Sulawesi region, has a seismicity history of earthquakes magnitudes range from Mw 4 to Mw 5, the structures including those that produce a low to moderate earthquakes compared to a series of major faults in Sulawesi Island. The greatest earthquake has occurred in 1997 with a magnitude of Mw 5.9, the structures in this region were reactivated after the Donggala-Palu earthquake attach Sulawesi Island in 2018. To reinforce the activity and paleoseismicity in this region we have conducted radiocarbon dating ages from two representative locations along the East Walanae fault (EWF), two samples were collected in the middle of Walanae Fault trace yielded ages of BC 3050 cal BP and 3990 cal BP ​​from the organic rich-soil shear band, two samples were collected in the north of Walanae Fault trace shows AD 101 cal pMC and 340 cal BP from the organic-rich soil horizon. Based on the results of radiocarbon dating ages, seismicity information and morphology analysis around the Walanae Fault region, we conclude that the Walanae fault is active and must remain a concern as an earthquake source that has potential hazards in this region, especially due to between the two structural lineaments of the West Walanae Faults (WWF) and East Walanae Fault (EWF) have lowlands that present a high risk of amplification of ground motions are inhabited by a high population among other cities on Sulawesi Island.

Keyphrases: Seismicity, Strike slip fault, Walanae Fault, earthquake hazard, radiocarbon, sengkang area

@booklet{EasyChair:4068,
  author    = {Asri Jaya and Osamu Nishikawa and Sahabuddin Jumadil},
  title     = {Paleoseismic of the Walanae Fault Zone in the South Arm of Sulawesi, Indonesia},
  howpublished = {EasyChair Preprint 4068},
  year      = {EasyChair, 2020}}