The icy wastes of Iceland are often crisscrossed by black lines and cross-hatchings. These patterns are the result of the interplay of volcanic ashes, snow, sun and wind. When one of the many volcanoes in Iceland erupts – which happens every few years – it spews up black volcanic ash. This forms ash clouds high above, which in form of rain come down onto the glaciers. The wind constantly blows dark dust and sand from the volcanic deserts onto the ice. Later snow covers the carpet of the black volcanic ash. In this way, white and black layers deposit on top of one another countless times over. When the ice flows, these dark and light layers move forward slowly bending, pressing against one another and buckling. Meanwhile, the sun and wind do their work on the surface. The layered package erodes in places. Fresh volcanic dust settles in the fissures of the glacier. This creates unique patterns such as those on the Sidujökull in southern Iceland. (aerial view)