Satellite radar shows continued slumping of west and southwest margins of Halema`uma`u crater 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 6 at 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 three images in the sequence, from May 29-June 6, show the development of several cracks outside Halema‘uma‘u (also seen in UAS footage of the crater) and inward slumping of a large portion of the western and southwestern crater rim. The west side of Halema‘uma‘u is clearly unstable, and it is likely that rockfalls and continued slumping will occur in the future.

Posted by USGS Volcanoes on Thursday, June 7, 2018