Weddell Seals - Part 3 - 4 - New (last?!) Search Area Campaign!


Hi All! As promised (threatened?), I’ve posted our last campaign to identify Weddell Seal habitat. You can find it on or go directly to the campaign here:

Thank you for the invaluable help this group in particular has provided to these campaigns. You truly are the subject matter experts on identifying seals from space!

I have tested this campaign a bit but if you see anything out-of-the-usual wrong, please let me know.

Stay tuned here - we are hoping to do something else as a thank you. And always love to see your fun finds and seal questions. Thanks again, loyal tomnodders!

Nice Share Badge

How many polygons do we have in this one? Edit 2: 222k?

Edit: And which area are we looking on this time?


I’m sorry to ask, but why are the polygons, at zoom level 0, of different sizes?

Edit: It’s very annoying!

Edit 2: It looks that the polygon has the “right” size when the polygon number is between 10,000 and 100,000, and the polygon is smaller when the polygon number is below 10,000 and from 100,000 and up. Does that make any sense?


Hi @Shaul, Incoming Novel!!

We have 226,315 polygons in this campaign. I hope nobody will feel too overwhelmed by that. On our last campaign, for example, we had over 3000 unique voters. So really, each voter technically only needs to vote on 75 polygons to get 1x coverage of the whole area! (we will get more coverage than that, especially on low-confidence tiles, but, this is just as an example of the light work - many hands).

Here’s what’s going on with the size of the polygons: this has to do with the trade-offs of choosing a map projection and the difficulty of projecting the latitude we are working in. As you change latitude, going further north or south, the tile is same area physically (“on the ground area”) but has to get taller in terms of pixels to be exactly the same size. This is the same reason why, when you look at a typical map of the world online, Antarctica, Greenland, etc will appear much larger compared to the more equatorial countries. We use a web mercator map projection in Tomnod (the usual projection for web-based map work), but virtually all projections will have issues like this at extreme latitudes like we are working in here. It’s the long-standing issue of taking a round world and trying to make it look flat on a map or computer screen. This is compounded by user screen size - Tomnod is trying to show you as much of the polygon as possible, so when there are small changes in a polygon size, it will exaggerate this to some extent to try to get more image to you.

The reason this wasn’t as big of an issue in our previous campaigns was that we were only working in one area of Antarctica each campaign, so the tiles appeared to be uniform. In this campaign we are cleaning up a few different habitats across Antarctica, so the differences between the tiles are quite noticeable and Tomnod is compensating for this.

Sorry to stick you with something annoying on our last campaign!


Keeps us on our toes.


Thanks for the explanation - I understand the problem.


Found one :blush:

…and another party :grin:


Oh wow, looks like there gathering again for a big time rave party :astonished:


And never where you want them!!!


Wow seals already @EmeraldEyes?? And here with you only on polygon 2 or so? This is interesting!


I did find a few more than that (though not as busy) within the 163 I’d managed before I paused for the evening and family arriving home :slight_smile:


I love your picture @Manarelle


Thank you, @Mel_Nod, for the very good information page in this campaign. It gives a lot of information on how to find seals.


Yes, those examples are a great help, having examples from the different terrains and in different hues to compare with or just to remind you is always useful.

I started my own collection for when I’m in doubt. So when I am in doubt and I’ve noting to compare with, I tend to go roaming around until I find a cluster seals I’m positive about :wink:
I’m kicking myself I didn’t think to pair them off though, as I was going along, for the subsequent phases :unamused:


Lots of seals here, singles/clusters scattered all round the map


Hedgehogs get close to the ground, sniffing out seals, hurricane damage, and whatever else is needed. :wink: Watermelon is a great reward.


Hello everybody! @Michelle4 tells me it’s International Day of the Seal!! :sparkles::tada::flags:

What better day than today and what better group to celebrate seals with? Thank you volunteers for being a part of this seal conservation effort.

Michelle posted an update to the Tomnod Blog as well:


I was hoping @Michelle4 would tell us the story of her trying to get to Antarctica and what she did while waiting… and when she plans to try again?


Happy International Seals Day :grin:


Just had to come in here to remind myself I did find some seals in this batch of maps. . . 'cos I’m struggling to find even a “maybe” the past few days :roll_eyes: