This map shows the topography of a portion of the Thetis region of Venus, using data acquired by the Magellan altimetry instrument. Colors represent the planetary radius, measured in kilometers. The 10-degree grid spacing is equivalent to approximately 1050 kilometers (651 miles). The east-west trending troughs near the center of the map are Diana and Dali Chasmata. These valleys are up to 4 kilometers (3 miles) deep in places. Slopes as steep as 25 degrees, extending over several kilometers, are found at the edges of the valleys. The existence of such dramatic relief suggests that active tectonic forces may be dynamically supporting the topography.
