Supporting dataset for the article: Triggered and recurrent slow slip in North Sulawesi, Indonesia

Abstract

Nearby faults interact with each other through the exchange of stress. However, the extent of fault interaction is poorly understood. In particular, interactions may lead to slow-slip activity, resulting in episodes of transient surface motion. Our study concentrates on Northwest Sulawesi (Indonesia), which hosts two fault zones with potential for major earthquakes and tsunamis: the strike-slip Palu-Koro fault and the Minahassa subduction zone. Thanks to a 20-year-long effort in geodetic monitoring, we are able to identify multiple periods during which surface velocities deviate from their interseismic trend. We use a Bayesian methodology with forward predictions of slip on the two fault interfaces to match the observations following the 2018 Palu earthquake, and infer that both deep afterslip on the Palu-Koro fault and slow slip on the Minahassa subduction interface have caused the observed transient surface motion. This finding represents the first recording of a slow slip event on the Minahassa subduction interface. We also infer that the subduction interface and the strike-slip fault are likely interacting on a regular basis.


Data

Least squares parameterization of GPS data contains the station positions, jumps, transients and velocities shown in figure 2A and S1-13 in .txt format.

RINEX GPS data contains RINEX files of the campaign stations after the 2018 Palu earthquake

Model data contains model output files used to create the figures 4,6,7, S12-17 in .txt format and two supporting images in .png format.