Does every map need a north arrow and scale bar?

By Aileen Buckley, Mapping Center Lead

World with orthographic projected coordinate system showing earthquakes

I had an interesting email conversation this morning with one of my mentors, and the subject revolved around whether all maps need a scale bar and north arrow. He was trained in the “old school” of cartography, as he admits. His cartography teacher once gave him a “D” on an assignment for “turning in a map with no stated scale, no north arrow, an inappropriate title, and no statement of where the data came from.” This sparked a conversation about whether all maps do need these map elements.

I teach my students that a north arrow and scale bar are not necessary on all maps — indeed some should not have them, such as orthographic views of the world. One common mistake I see is a north arrow on a smaller scale map (say the United States) in a Lambert Conformal Conic or Albers Equal Area projection — on these types of map, north is only North along the central meridian (due to the convergence of the meridians toward the pole). But we still have an obligation to help the map reader with scale and orientation, so instead of a north arrow the graticule should be shown. A cardinal rule is that a large scale map oriented such that North is not “up” must have an orientation indicator, most easily shown with a north arrow, since these tend to be larger scale maps.

However, I do think that all maps should have an appropriate title! It should also be possible for someone to find out where the data for a map came from, though there may be ways for people to convey this information other than text printed on the page layout. For example, the data that relates to a map on a page in an atlas can be located elsewhere — perhaps in a list of courses toward the end of the book.

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2 Comments

  1. MappingCenterTeam says:

    This question came up with us not too long ago. I like the Canadian convention — use a star by the north arrow if it’s true north or a box by the arrow if it’s grid north. (For those rare occasions when you’re using magnetic north, use a half arrow.)

    Yeah, I know, we’re Americans, but I think it’s easier putting a little star or box next to the north arrow than trying to put a “G” or “T”
    next to the “N” on the ready-made north arrow.

    Posted by Joe McCollum on July 09, 2007 at 11:53 AM PDT
    I think part of the reason this is a successful approach is because it is an accepted and familiar convention — if we wanted to use it in the U.S., for example, we could not assume that people would know what the symbols means so we would also have to provide additional information (in the form of a note or legend) to the map readers so they could decipher the symbols. So this would be a good solution — we just make sure our readers can understand what the additional symbols mean.

    One other point, on a map like the one above, you couldn’t use any north arrow, regardless of whether it is true, magnetic or grid north.
    Posted by Aileen Buckley on July 09, 2007 at 05:09 PM PDT
    I must agree that not all maps need a north arrow and a scale bar, and a title is always must. I also think some kind of source, so the map can be reproduced or changed from the original. I hate getting a map that was already made and I have to find it and make a few changes and I have no idea where this map came from!
    Posted by Heather Baker on July 20, 2007 at 09:04 AM PDT

  2. cfrye says:

    This Ask a Cartographer question provides a great example about a north arrow for what we were talking about here.