This is a photograph of Uluru, in the Northern Territory of Australia, on a hot and humid summer afternoon. As lightning flashed about, torrential rains swept across the landscape and silver rivulets of water began to rush down the sides of the mountain. Uluru is made of red-coloured Proterozoic arkosic sandstones, a coarse grained lithology rich in quartz and feldspars. However, on rare days such as this, the storm clouds and moisture in the atmosphere filter out much of the red end of the light spectrum and make the rock appear purple.
By Prof. John Clemens, University of Stellenbosch
Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.
