The 2000 Luwuk Earthquake and Seismic Context of Sulawesi

On 4 May 2000 at 04:21 local time, a magnitude 7.6 earthquake struck 89 km east of Luwuk, Indonesia, at a depth of 26 km. This event remains the sole strong earthquake recorded in the region since 1 January 2000 according to available catalogs, with its epicenter effectively coinciding with the listed location.

Sulawesi occupies a tectonically intricate zone at the convergence of the Australian, Sunda, Philippine Sea, and Caroline plates. The island’s distinctive K-shaped morphology results from long-term collision and strike-slip faulting, most notably along the Palu-Koro Fault system that transects central Sulawesi. These structures accommodate rapid lateral motion and generate frequent moderate-to-large earthquakes at shallow to intermediate depths.

The 26 km focal depth of the 2000 event places it within the seismogenic portion of the crust, consistent with regional fault geometries. Such depths often produce strong ground shaking across eastern Sulawesi, although detailed damage assessments for this specific shock are limited in public records. The surrounding region continues to exhibit elevated seismic hazard due to ongoing plate interactions and the presence of both thrust and strike-slip sources.

No subsequent events of comparable magnitude have been catalogued in the immediate vicinity since the turn of the century, underscoring the 2000 earthquake as a benchmark for local seismic potential. Continued monitoring by regional networks remains essential for refining hazard models in this rapidly deforming part of the Indonesian archipelago.

References

USGS Earthquake Catalog (event parameters)
Prompt data provided for the 4 May 2000 Luwuk event