25 Apr 2017

Ancient Volcanoes of the D’Entrecasteaux Archipelago

Sailing in the narrow channel between Fergusson and Normanby Islands, in the D’Entrecasteaux archipelago of Papua New Guinea, we were surrounded by the cones of ancient volcanoes. Now they lie dormant and cloaked in jungle green, but they are certainly not extinct. At the base of Deidei volcano we explored a large area of hot-springs, with bubbling pools of mud and water. We followed our guides carefully. The rocky crust was thin and punctuated with holes. Beneath lay scalding water. Where the water flowed out and over the surface it deposited lines of travertine crystals, creating a series of shallow terraces. Steam and a faint whiff of sulphur filled the air, the atmosphere positively prehistoric.

Later in the day, in the sea around Dobu volcano, we found different evidence of the hot rocks not far below. In shallow water, amongst beautiful coral and seagrass, streams of bubbles erupted from the seafloor. In one location, powerful jets of steam burst continuously from fissures in the rocks, their rumblings clearly audible underwater. The gentler streams of bubbles danced and shimmered in the low afternoon sunlight. Snorkelling through them was a unique and magical experience, a beautiful reminder that these islands are definitely still geologically alive.

Text and image from Karen Bass & Neil Nightingale