Show Navigation | Hide Navigation
You are here:
Map projections and coordinate systems > Supported map projections

McBryde-Thomas Flat-Polar Quartic

Release 9.2
Last modified August 3, 2007
E-mail This Topic Printable Version Give Us Feedback

Print all topics in : "Supported map projections"

Related Topics


This equal-area projection is primarily used for world maps.

Illustration of the McBryde-Thomas Flat-Polar Quartic projection

Projection method

A pseudo cylindrical equal-area projection in which all parallels are straight lines and all meridians, except the straight central meridian, are equally spaced, fourth-order (quartic) curves.

Linear graticules

All parallels are unequally spaced straight lines that are closer together at the poles. The poles are straight lines one-third as long as the equator. The central meridian is a straight line 0.45 times as long as the equator.



Shapes are stretched north–south along the equator, relative to the east–west dimension. This stretching decreases to zero at 33°45' N and S at the central meridian. Nearer the poles, features are compressed in the north–south direction.


Equal area.


Distorted except at the intersection of 33°45' N and S and the central meridian.


Scale is distorted everywhere except along 33°45' N and S.


Useful only as a world map.

Uses and applications

Thematic maps of the world.




Please visit the Feedback page to comment or give suggestions on ArcGIS Desktop Help.
Copyright © Environmental Systems Research Institute, Inc.