<p>Commenter Universal Learner points out "Currently NOAA says there is only one ocean"</p>

<p><a href="https://oceanservice.noaa.gov/facts/howmanyoceans.html" rel="nofollow noreferrer">https://oceanservice.noaa.gov/facts/howmanyoceans.html</a></p>

<p>and "At the comments of the question I linked you can read a great: "I once heard a lovely description of the world's seas (by a polar scientist) as "One ocean with three big estuaries" ;-) "</p>

<blockquote>
  <p>While there is only one global ocean, the vast body of water that
  covers 71 percent of the Earth is geographically divided into distinct
  named regions. The boundaries between these regions have evolved over
  time for a variety of historical, cultural, geographical, and
  scientific reasons.</p>
  
  <p>Historically, there are four named oceans: the Atlantic, Pacific,
  Indian, and Arctic. However, most countries - including the United
  States - now recognize the Southern (Antarctic) as the fifth ocean.
  The Pacific, Atlantic, and Indian are known as the three major oceans.</p>
  
  <p>The Southern Ocean is the 'newest' named ocean. It is recognized by
  the U.S. Board on Geographic Names as the body of water extending from
  the coast of Antarctica to the line of latitude at 60 degrees South.
  The boundaries of this ocean were proposed to the International
  Hydrographic Organization in 2000. However, not all countries agree on
  the proposed boundaries, so this has yet to be ratified by members of
  the IHO. The U.S. is a member of the IHO, represented by the NOS
  Office of Coast Survey.</p>
</blockquote>

<p>And they have a graphic saying 1 world ocean.  Historically 4 basins.  Now 5 basins. And that the boundaries aren't agreed upon by all countries. Though that text refers to a basin as an ocean, so their terminology doesn't quite match their graphic. </p>

CC BY-SA 4.0
2019-05-25T18:40:12.753Z
Do we include the landlocked Caspian Sea  (371,000 km^2/ 143,200 mi^2)) as part of the ocean?  Or even the very nearly landlocked Black Sea?
jamesqf
CC BY-SA 4.0
2019-02-17T19:03:29.283Z
2019-02-17T19:03:29.283Z
barlop
<p>How is the total area of the world's oceans 361 million square kilometres? I can't see how the five individuals ones add to that.</p>

<p>When I Google <em>how many squared km is this/that ocean</em>, I get</p>

<p><a href="https://i.sstatic.net/RGT5M.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/RGT5M.png" alt="enter image description here"></a></p>

<p>When add the areas of those five oceans,  106.5+161.8+70.56+14.06+20.33</p>

<p><a href="https://i.sstatic.net/ds0PI.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ds0PI.png" alt="enter image description here"></a></p>

<p>I get 373.25 million sq km.</p>

<p>Yet the world ocean, which should be the sum of the 5 oceans, is 361 million sq km.</p>

<p>If I try this site  <a href="https://www.infoplease.com/world/world-geography/oceans-and-seas" rel="nofollow noreferrer">https://www.infoplease.com/world/world-geography/oceans-and-seas</a></p>

<p>It says Pacific = 155.557,  Atlantic = 76.76,  Indian = 68.556, Southern =2 0.327, Arctic = 14.056</p>

<p>155.557 + 76.76 + 68.556 + 20.327 + 14.056 = 335 sq km</p>

<p>So, also, not 361 million square km</p>

<p>Any idea why the figures differ and what are the correct figures?</p>

CC BY-SA 4.0
2018-07-28T14:38:54.287Z
@Universal_learner  I know that link has seas too, and of course I didn't add seas to the sum, I only wanted oceans.  mediterranean and caribbean are seas, not oceans. I am only looking at oceans.
barlop
CC BY-SA 4.0
2018-07-28T14:45:12.710Z
@Universal_learner i'm not asking about the measurement of the world's total surface. Just those oceans. Google is providing info that is labelled as specific oceans, and  world ocean,should be the total of all the oceans
barlop
CC BY-SA 4.0
2018-07-28T23:22:40.210Z
Since the boundaries between the oceans are at best fuzzy, it shouldn't be surprising that different sources add up to different numbers. Since you are relying on unreliable sites (even wikipedia is an unreliable site in this regard), it shouldn't be surprising at all that you are getting contradictory results.
David Hammen
CC BY-SA 4.0
2018-07-29T10:41:38.180Z
An "ocean" is a loosely defined term. Unlike countries that mostly have well defined borders, oceans are defined according to a somewhat vague area.
Gimelist
<ocean><oceanography>
How is the total area of the world's oceans 361 million sq km?
barlop
# How is the total area of the world's oceans 361 million sq km?

(Asked by: username_0 on 2018-07-28)

How is the total area of the world's oceans 361 million square kilometres? I can't see how the five individuals ones add to that.

When I Google *how many squared km is this/that ocean*, I get

[![enter image description here](https://i.sstatic.net/RGT5M.png)](https://i.sstatic.net/RGT5M.png)

When add the areas of those five oceans, 106.5+161.8+70.56+14.06+20.33

[![enter image description here](https://i.sstatic.net/ds0PI.png)](https://i.sstatic.net/ds0PI.png)

I get 373.25 million sq km.

Yet the world ocean, which should be the sum of the 5 oceans, is 361 million sq km.

If I try this site <https://www.infoplease.com/world/world-geography/oceans-and-seas>

It says Pacific = 155.557, Atlantic = 76.76, Indian = 68.556, Southern =2 0.327, Arctic = 14.056

155.557 + 76.76 + 68.556 + 20.327 + 14.056 = 335 sq km

So, also, not 361 million square km

Any idea why the figures differ and what are the correct figures?

**Tags:** ocean, oceanography

> **Comments:**
> **username_0**: @Universal_learner  I know that link has seas too, and of course I didn't add seas to the sum, I only wanted oceans.  mediterranean and caribbean are seas, not oceans. I am only looking at oceans.  
> **username_0**: @Universal_learner i'm not asking about the measurement of the world's total surface. Just those oceans. Google is providing info that is labelled as specific oceans, and  world ocean,should be the total of all the oceans  
> **username_1**: Since the boundaries between the oceans are at best fuzzy, it shouldn't be surprising that different sources add up to different numbers. Since you are relying on unreliable sites (even wikipedia is an unreliable site in this regard), it shouldn't be surprising at all that you are getting contradictory results.  
> **username_2**: An "ocean" is a loosely defined term. Unlike countries that mostly have well defined borders, oceans are defined according to a somewhat vague area.  

---

## 1 answers

### Answer by username_0 on 2019-02-17. Score: 1

Commenter Universal Learner points out "Currently NOAA says there is only one ocean"

<https://oceanservice.noaa.gov/facts/howmanyoceans.html>

and "At the comments of the question I linked you can read a great: "I once heard a lovely description of the world's seas (by a polar scientist) as "One ocean with three big estuaries" ;-) "

> While there is only one global ocean, the vast body of water that
> covers 71 percent of the Earth is geographically divided into distinct
> named regions. The boundaries between these regions have evolved over
> time for a variety of historical, cultural, geographical, and
> scientific reasons.
>
> Historically, there are four named oceans: the Atlantic, Pacific,
> Indian, and Arctic. However, most countries - including the United
> States - now recognize the Southern (Antarctic) as the fifth ocean.
> The Pacific, Atlantic, and Indian are known as the three major oceans.
>
> The Southern Ocean is the 'newest' named ocean. It is recognized by
> the U.S. Board on Geographic Names as the body of water extending from
> the coast of Antarctica to the line of latitude at 60 degrees South.
> The boundaries of this ocean were proposed to the International
> Hydrographic Organization in 2000. However, not all countries agree on
> the proposed boundaries, so this has yet to be ratified by members of
> the IHO. The U.S. is a member of the IHO, represented by the NOS
> Office of Coast Survey.

And they have a graphic saying 1 world ocean. Historically 4 basins. Now 5 basins. And that the boundaries aren't agreed upon by all countries. Though that text refers to a basin as an ocean, so their terminology doesn't quite match their graphic.

> **Comments:**
> **username_3**: Do we include the landlocked Caspian Sea  (371,000 km^2/ 143,200 mi^2)) as part of the ocean?  Or even the very nearly landlocked Black Sea?  

---

