Kilauea volcano (Hawai’i): localised summit deformation at Kīlauea detected in a 12-day Sentinel-1D interferogram

Wrapped interferometric phase at Kīlauea, Hawaiʻi, from a Sentinel-1D VV pair spanning 24 September – 6 October 2026 (12-day temporal baseline). Inset: wrapped phase along a profile across the fringe pattern; the sawtooth shows three full phase wraps over the readable section, giving a total phase difference of 22.2 rad, equivalent to 9.8 cm of relative line-of-sight displacement. (image: Sentinel-1, processed by Martin Kelko)

The interferometric Sentinel-1D pair in VV polarisation of the volcano, acquired on 24 September and 6 October 2026, shows a compact set of concentric fringes confined to the summit caldera, superimposed on broad, long-wavelength phase gradients across the wider scene.

The displacement corresponds to 9.8 cm of relative displacement in the satellite line of sight over the 12-day interval. One full colour cycle corresponds to 2.77 cm of displacement in the satellite line of sight. Concentric fringes within the summit caldera indicate a localised deformation source. The broad, long-wavelength colour gradients elsewhere in the scene are consistent with tropospheric delay rather than ground motion, and the speckled areas are decorrelated, mainly over vegetated terrain