GPS measurementssuggest that the trench accommodates 15 mm/yr of slip within the Makassar Strait withcurrent elastic strain accumulation. The tectonic boundary between North Sula andManado blocks is the Gorontalo Fault, moving right laterally at about 11 mm/yr andaccumulating elastic strain. The 42 mm/yr relative motion between North Sula andMakassar blocks is accommodated on the Palu-Koro left-lateral strike-slip fault zone. Thedata also indicate a pull-apart structure in Palu area, where the fault shows a transtensivemotion and may have a complex geometry involving several active strands.