Land topography is a digital image of the three-dimensional structure of the Earth's surface. Shading indicates changes in slope or elevation. The relief shading in this topographic map comes mostly from elevation data collected by space-based radars. A radar in space sends a pulse of radio waves toward the earth and measures the strength and length of time it takes a signal to bounce back. From this information, scientists can determine the height and shape of the features on the surface.
Topography not only gives a realistic picture of what the Earth's surface actually looks like, it also helps scientists determine things like how rivers and streams drain through the landscape, where lowlands are prone to flooding, how plate tectonics or erosion are building or wearing away mountains, where hills may be prone to landslides, or how a volcanic eruption changed the shape of a mountain. Topography is also one of the factors that influences where particular ecosystems exist. Therefore topography is one of the factors that scientists can use to predict where certain plants or animals, such as endangered species, might be found.
The full resolution of these images has been broken up into tiles as listed below. To understand the naming scheme please read about our global image grid.