Map-making is a tricky business with many variables to consider that can directly change how someone interprets the land and people in a location. The Cartography Playground is a simple site to test these variables interactively. Learn about algorithms, mess with appearance, and toggle through representations.
Tags: algorithms, cartography
A gray piece of paper moves along a gradient. You won’t believe your eyes.
Tags: illusion, perception
The Padma River in Bangladesh is constantly shifting its 75-mile path. Joshua Stevens for the NASA Earth Observatory shows what the shifting looked like through satellite imagery, over a 30-year span.
The upper section of the Padma—the Harirampur region— has experienced the most erosion and shows the most notable changes. The river has become wider at this section by eroding along both banks, although most activity occurred on the left bank. Using topographic, aerial, and satellite imagery, scientists found that the left bank shifted 12 kilometers towards the north from 1860 to 2009 and developed a meandering bend. The river left a scar where the water once flowed, as you can see in the 2018 image.
See also the dramatic shifts of the Ucayali River in Peru.
Tags: environment, NASA, satellite imagery, water