Quartic authalic projection
Pseudocylindrical equal-area map projection
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Quartic_authalic_projection_SW.jpg/300px-Quartic_authalic_projection_SW.jpg)
In cartography, the quartic authalic projection is an equal-area projection developed by Karl Siemon in 1937 and independently by Oscar S. Adams in 1944.[1] The meridians in this projection are fourth-order polynomial curves.[2] The projection is similar to the sinusoidal projection in appearance and distortion properties.