CountryData and the areas of the world

Question

If I add the water area and the land area of the world, I get the same number as if I asked for the total area of the world in the first place:

In[1]:= {CountryData["World", "WaterArea"] + CountryData["World", "LandArea"],
         CountryData["World", "Area"]}

Out[1]= {5.10066*10^8, 5.10066*10^8}

Now, if I add the area of all the countries, it does not add up to the total land area of the world:

In[2]:= {Total[CountryData[#, "Area"] & /@ CountryData[]], 
         CountryData["World", "LandArea"]}

Out[2]= {1.35936*10^8, 1.4912*10^8}

So my question is: are some countries missing? Are the ice caps to blame?

"Are the ice caps to blame?" - in a sense, yes; note that Antarctica is not in the list returned by CountryData[]. — J. M.'s missing motivation, Sep 04 '12 at 21:55
@J.M. Curiously CountryData["World", "LandArea"] - CountryData["Antarctica", "Area"] < Total[CountryData[#, "Area"] & /@ CountryData[]] — Dr. belisarius, Sep 04 '12 at 21:56
Antarctica is not a sovereign country, but it is part of the world — rm -rf, Sep 04 '12 at 21:57
@belisarius: compare as well the output of Total[Flatten[CountryData[#, "Area"] & /@ CountryData["Continents"]]] with CountryData["World", "LandArea"]. Curious indeed. — J. M.'s missing motivation, Sep 04 '12 at 22:01
@J.M. Try Complement[Flatten[CountryData[#] & /@ CountryData["Continents"]], CountryData[]] — Dr. belisarius, Sep 04 '12 at 22:04
@belisarius, it returns what I expect. My point was that totaling all the areas of those gives a result somewhat different from CountryData["World", "LandArea"]... — J. M.'s missing motivation, Sep 04 '12 at 22:10
@wxffles No, we are still around and listed in CountryData. We are not part of Australia yet. :-) — Matariki, Sep 05 '12 at 01:31
https://mathematica.stackexchange.com/questions/179031/itsy-bitsy-teeny-weeny-little-polka-dot-island-in-countrydata has some other peculiarities in Mathematica's view of what constitutes the world. — , Oct 19 '18 at 05:21

score 5 · Accepted Answer · edited Oct 03 '12 at 19:23

5

So both

CountryData["World", "LandArea"] - 
(CountryData["Antarctica", "LandArea"] +
 Total[CountryData[#, "LandArea"] & /@ CountryData[]])

and

CountryData["World", "LandArea"] - 
  Total[Flatten[CountryData[#, "LandArea"] & /@ CountryData["Continents"]]]

give $3.42636\times10^6 \text{ km}^2$ of area missing. That is approximately the area of current Arctic ice (I Googled it).

Also, there are some places that occupy a land area, but are not within any country (about maybe $10^4 \text{ km}^2$ in total); e.g., the Saudi–Iraqi neutral zone.

edited Oct 03 '12 at 19:23

J. M.'s missing motivation

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answered Oct 03 '12 at 10:19

swish

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Great! Let's reevaluate those commands in a year to see if they change. – Gustavo Delfino Oct 03 '12 at 14:01

CountryData and the areas of the world

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