An Icelandic guide leads a tour into the heart of an ice cave in Mýrdalsjökull Glacier while the Katla Volcano sleeps below.
Marbled colors of white, black and blue ice are illuminated by a skylight in the Katla Ice Cave, Iceland.
Katla Volcano is covered by several hundred meters of ice from the Mýrdalsjökull Glacier in southern Iceland. This active volcano has an eruption interval of 20–90 years, causing massive mud flows, or jökulhlaup, when the subglacial eruptions melt the massive ice cap from below.