August 1, 2016 overflight of Makushin Volcano's summit crater, roughly 2 km above sea level (6,000 ft). The crater is about 2x3 km and filled with ice, but there is a little hot spot at the top with actively degassing fumaroles and a small lake. We could smell sulfur downwind here, and see a thin, yellow coating of sulfur on the surrounding ice. For better image quality, click the "full size" link below.