What does Antarctica really look like Projections are

What does Antarctica really look like? Projections are important… Sharon Grant – i. Dig. Bio Train-the-Trainers Geo-referencing Workshop II. August 2013

It was easier when the world was flat! Aristotle Magellan Pythagoras

Make is flat again! • Transforming a three dimensional space onto a two dimensional map is called 'projection'. • Projection formulas are mathematical expressions which convert data from a geographical location (latitude and longitude) on a sphere or spheroid to a representative location on a flat surface.

Distortions • All projections result in some distortion of the relationships between features on the sphere when they are projected onto a flat surface. These include: – – • the direction between one feature and another the distance between one feature and another the shape of a feature the area of a feature These distortions are in part due to the changing relationship between latitude and longitude as you move around the earth. Near the Equator a ‘block’ of 1°x 1° latitude and longitude is almost a square, however the same ‘block’ near the poles is almost a triangle.

China’s 1418 World Map / Oronce Fine heart-shaped map 1531 Piri Re’s 1513 /

Mercator

Lambert conformal conic

Azimuthal equidistant

Polar stereographic

Resources • • • http: //www. icsm. gov. au/mapping/about_projections. html http: //classroom. antarctica. gov. au/exploring/mapping/map-projections http: //www. icsm. gov. au/mapping/about_projections. html http: //new. antarctica. ac. uk/apc/ http: //nsidc. org/api/metadata? id=nsidc-0075 http: //www. antarctica. ac. uk/about_antarctica/geography/maps. php http: //strangemaps. wordpress. com/? s=Antarctica http: //badarchaeology. wordpress. com/2013/01/03/old-maps-the-americasand-antarctica/ http: //www. colorado. edu/geography/gcraft/notes/mapproj. html http: //gis. stackexchange. com/questions/664/whats-the-difference-between-a -projection-and-a-datum

Something interesting at the end http: //www. flickr. com/photos/sbprzd/sets/72 057594138628700/