Lava deltas are fan-shaped patches of new land that form along coasts when lava flows directly into the ocean. When they are built on steep marine slopes, they can easily collapse.
On January 3, 2017, the Operational Land Imager (OLI) on Landsat 8 captured an image showing the aftermath of the collapse. For comparison, the second image shows the same area on October 13, 2015. Almost all of the Kamokuna lava delta is now gone. The collapsed portion of the sea cliff extended about 180 meters (590 feet) east of the delta edge, and cut inland about 70 meters (230 feet) from the shoreline. (The U.S. Geological Survey has posted a detailed map showing both of these areas.) In the 2017 image, a plume of steam and volcanic gases is rising from waters west of the collapse, in an area where lava continues to flow into the sea.