Aurora over Katla, IcelandKatla is one of Iceland's most dangerous volcanoes, buried beneath the Mrdalsjkull ice cap. On this particular night, the sky above it was anything but threatening. A strong aurora display swept across the darkness, green and luminous, reflected in the braided glacial channels that fan out across the black sand below. I love the way the river splits and reforms around that dark sediment island in the foreground. It gives the image depth, pulls your