Kīlauea Volcano — Halema`uma`u Crater Enlargement
This animated GIF shows a sequence of radar amplitude images that were acquired by the Agenzia Spaziale Italiana CosmoSkyMed satellite system. The images illustrate changes to the caldera area of Kīlauea Volcano that occurred between May 5 and June 14 at about 6:00 a.m. HST. The satellite transmits a radar signal at the surface and measures the strength of the return, with bright areas indicating a strong return and dark areas a weak return. Strong returns indicate rough surfaces or slopes that point back at the radar, while weak returns come from smooth surfaces or slopes angled away from the radar. Over time, expansion of the summit eruptive vent within Halema‘uma‘u crater and the widening of Halema‘uma‘u itself are clear. The last four images in the sequence, from May 29-June 14, show the development of several cracks outside Halema‘uma‘u (also seen in recent UAS footage of the crater) and inward slumping of a large portion of the western, southwestern, and northern crater rim. Much of this motion appears to be coincident with the small explosions from the summit that have taken place on a near daily basis over the past 2 weeks. We expect this slumping to continue as long as the explosions and overall subsidence persist.