We’ve all had to deal with it. That infernal seam that runs along the International Dateline. It’s no big deal when your coordinate system uses 180 as a split, but it rears up when your projected coordinate system isn’t rectangular or has a center longitude other than zero.
Look at poor Antarctica, with an embarrassing seam showing. Well guess what! It’s not Antarctica’s fault; it’s living as a geographic coordinate system and has been asked to contort into a projected coordinate system. Of course there’s going to be a seam. I, for one, applaud Antarctica for being so accommodating and projecting on the fly.
But still it would be nice if that line weren’t there…
![](https://www.esri.com/arcgis-blog/wp-content/uploads/2021/02/Zipper.jpg)
Not to worry! I’ll show you how to…
- Hide it, if that’s good enough. But I’ll also show you how to…
- Fix it!
Ready?
0:00 What’s up with that outfit? It’s cold in Michigan. We dress in layers.
0:12 Ah that International Dateline dragging its feet right through your polygon.
0:22 Here’s why you have that seam (thank Bojan Šavrič for the explanation).
1:15 Here’s an easy hack to hide that seam (drag your stroke beneath the fill).
2:00 Here’s an alternate hack the does the same thing, just with two layers.
2:47 Ok, those are some band-aids. How do we fix this for good though?
2:58 Create a re-projected version of the data in a Projected Coordinate System.
3:47 Editing out the vestigial nodes that sit at the International Dateline.
4:42 Bonus tip: how to copy over the symbology of one layer to another.
Ok, happy non-vestigial-International-Dateline-mapping my friends!
Love, John
Article Discussion: