Context map of the Iani Chaos region on Mars

Iani Chaos is a large depression with dimensions of 330 kilometres in length and 430 kilometres in width, located at 2.8° south and 342.5° east. Individual blocks of rock and hills form a disrupted, knobby pattern in an apparently 'chaotic' distribution. Terraces and 'islands' are likely remnants of the pre-existing surface, which collapsed after cavities had formed beneath it - ice in these cavities might have been melted by volcanic heat and flowed into Ares Vallis towards the northern lowlands. Due to the hints of water having formed it, such a landscape is of special geological interest but it is also well suited to present the design and the potential of the topographic map series.