Measuring ground deformation provides insights into changes in complex geophysical systems, such as volcanoes. The launch of the synthetic aperture radar (SAR) satellite Sentinel-1 has ushered in a new era for Interferometric Synthetic Aperture Radar (InSAR), enabling the measurement of global volcanic deformation every 12 days. This study takes advantage of these advancements to investigate the presence of deformation at difficult-to-monitor equatorial island volcanoes, such as Halmahera (North Molucca Islands, Indonesia). The majority of interferograms from the past 3 years display a deformation signal at the summit crater of the Halmahera volcano Ibu, where a lava dome has been growing since 1998. The deformation signal is consistent with a subsidence pattern that is constant throughout time. The subsidence rate increases towards the crater center, with a maximum rate of about -16.7 cm per year over about 270 meters in the NNW of the crater and about -9.2 cm per year over about 300 meters to the E. Subsidence can be plausibly attributed to the cooling and compaction of extruded dome material, but this explanation may be just one factor among a variety of deeper-seated deformation processes in the dome interior. In addition to deformation, SAR data was used to calculate an average extrusion rate of about .3 cubic meters per second at Ibu from 2000 to 2013, and determine changes in lava flow morphology over the past 3 years.