Do any countries have geographical centres outside their borders?

Factual Questions
1

Let us define the geographical centre of a country as the point with the minimal sum of squared Euclidean distances between itself and every point within the country’s land borders, disregarding elevation.

Under this definition, are there any countries whose geographical centre lies on a point of land outside their borders? I am thinking that Somalia might be one due to its hooked shape—it looks like the centre of Somalia might actually be in Ethiopia. However, I’m not sure how I’d go about proving or disproving this. Are there any mathematically or geographically minded Dopers who can find the centre?

Besides Somalia, are there any other countries that probably or definitely meet the criteria?

2

You might also get this from countries with multiple disconnected pieces. I wouldn’t be surprised if French Guiana was enough to pull the centroid of France out of its borders.

Looking it up online, approximating both continental France and Guiana as circles, it looks like Guiana would pull the centroid about 900 km, but it’s only about 400 km from the center of contiguous France to the furthest contiguous point. So unless there are other overseas French districts in the opposite direction large enough to counterweight Guiana, it looks like France probably meets your criteria.

3

Yes, but what are the chances that this centroid is on land, per my question? Probably a lot of archipelago countries also have centres outside their land borders, but these centres will almost always be in the sea rather than in another country.

4

According tothis, the geographical center of Croatia is evidently in Bosnia and Herzegovina. Looking at the map of Croatia, this seems likely.

5

Denmark would be in the North Sea between Greenland and Jutland.
Norway would be dragged south quite a bit by Queen Maud Land, it’s Antarctic territory.

6

The first one fails the land criteria. The second looks to be near Angola.

7

Just looking at the map, I would guess that the geographical center of Vietnam is probably in Laos. Laos might fill the bill too.

8

Oh, good one.

Denmark doesn’t count if its centre is in the sea. (Remember, my question is about centres on land.) But Norway is a very interesting case. Its Antarctic claims are many times the size of Norway proper. It wouldn’t surprise me if this puts the centre of Norway somewhere in Africa.

9

Here’s a site with a list of centroids for most countries.

Vietnam’s is in Laos. Laos’ is barely within its own borders. Looks like Somalia is still within its own borders as well.

10

Spain’s might be in Southern Portugal, due to the Canary Islands being so much further than the Balearics. What’s for sure is that it’s neither on Cerro de los Ángeles (which is officially the center of the Iberian Peninsula) nor in Madrid (whose central position was the official reason given by Felipe II of Spain and I of Portugal to move his capital there).
Great Antibob, I can’t see anything but a blur of green squares (Edge, I’m at work). Which browser are you using?

11

But it looks like it’s showing two centroids for Somalia, one for separatist Somaliland in the north, and one for Somalia without Somaliland.

12

That map also shows the centroid of Israel being on the West Bank.

13

It’s showing a centroid in Jammu and Kashmir, in the disputed area by the Indian, Pakistani, and Chinese borders. Whose centroid is that supposed to be? None of the centroids are labelled in my browser.

14

Oh, never mind—I see that you first have to click the “i” icon to get the details. The centroid I asked about is assigned to Kashmir. This isn’t an independent state, though maybe whoever made the map thought it was.

15

Ah, right, I missed the bit in the OP about the point being on land. France’s would be somewhere in the North Atlantic.

16

No way—those islands are tiny compared to the area of mainland Spain. Their effect on the position of the centroid is negligible.

17

Yeah…it’s definitely not perfect, relies on several geopolitical assumptions, and hasn’t been updated in a while, but it is still a reasonably good reference for the question.

It’s definitely an interesting OP. There are several other countries with centroids outside their borders but in the water. The additional restriction to land cuts that number down to a very few.

18

The map includes separate centroids for many semi-sovereign or disputed territories, as for example the Isle of Man, Channel Islands, Greenland, and Cyprus and Northern Cyprus, as well as the case of Somalia and Somaliland. What’s not clear is if the centroid of the parent country excludes these separate territories.

19

Actually, that centroid map is showing France’s as being in northern Spain, presumably because of French Guiana and the rest of France’s overseas departments. (And French Guiana is not shown with a centroid of its own.)

20

In that case, the other departments shifted the centroid enough to be significant, because the geodesic from the center of continental France to Guiana passes north of Spain.

EDIT: That, or they’re basing their centroid calculations on a rectangular interpretation of latitude and longitude, without taking the spherical Earth into account. That would put the “line” (actually a constant-bearing curve) from continental France to Guiana over Spain.