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New Estimates Say Earth's Oceans Smaller Than Once Believed

timothy posted more than 3 years ago | from the deeper-than-my-love-for-you dept.

Earth 263

Velcroman1 writes with this snippet from Fox News: "Using lead weights and depth sounders, scientists have made surprisingly accurate estimates of the ocean's depths in the past. Now, with satellites and radar, researchers have pinned down a more accurate answer to that age-old query: How deep is the ocean? And how big? As long ago as 1888, John Murray dangled lead weights from a rope off a ship to calculate the ocean's volume — the product of area and mean ocean depth. Using satellite data, researchers from the Woods Hole Oceanographic Institute set out to more accurately answer that question — and found out that it's 320 million cubic miles. And despite miles-deep abysses like the Mariana Trench, the ocean's mean depth is just 2.29 miles, thanks to the varied and bumpy ocean floor."

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263 comments

I estimate (-1, Offtopic)

Vinegar Joe (998110) | more than 3 years ago | (#32270918)

It's bigger than a breadbox.

Re:I estimate (1)

rubycodez (864176) | more than 3 years ago | (#32271468)

"A big enough box could hold the world" -- Carl Sanburg

Re:I estimate (3, Informative)

daem0n1x (748565) | more than 3 years ago | (#32272088)

For the 640 billion people who have no idea what the fuck a mile is, here is your public translation service. The ocean's volume is about 1300 million cubic kilometres, and the average ocean depth is about 3.7 Km.

Re:I estimate (5, Funny)

ascari (1400977) | more than 3 years ago | (#32272266)

640 billion people? I suppose new estimates say Earth's population is larger than once believed...

Re:I estimate (1)

daem0n1x (748565) | more than 3 years ago | (#32272368)

Shit, I forgot the dot. 6.40 billion people. Sorry, too late to be awake.

Re:I estimate (0)

Anonymous Coward | more than 3 years ago | (#32272650)

Shit, I forgot the dot. 6.40 billion people. Sorry, too late to be awake.

That``s just a bit more than the most recent Tea Party event.

Re:I estimate (1)

c6gunner (950153) | more than 3 years ago | (#32272698)

It's still wrong. For one thing, it's more like 6.697 now. More importantly, the zero on the end suggests two significant digits, which is much more accurate than your actual estimate. You should have written it as 6.4, or, preferably, 6.7.

Re:I estimate (0, Flamebait)

The Hatchet (1766306) | more than 3 years ago | (#32272548)

I don't know guys, these is coming from FOX news. Reminds me of the kind of "the universe isn't really 18 billion years old, more like 5000" or "the earth is really 4 billion years old, its more like 5000" or "the universe isn't THAT big, its really only us in the center with a bunch of crystal spheres" or "the earth isn't that big, if you try to sail around it, you will just fall off the edge" or ...

Maybe FOX got it from a real news source, but I don't trust FOX.

Re:I estimate (5, Insightful)

c6gunner (950153) | more than 3 years ago | (#32272714)

Maybe FOX got it from a real news source, but I don't trust FOX.

That just means you're being brainwashed by a different news sources. You shouldn't trust ANY of them.

What were the earlier estimates? (2, Interesting)

cytoman (792326) | more than 3 years ago | (#32270944)

Using satellite data, researchers from the Woods Hole Oceanographic Institute (WHOI) set out to more accurately answer that question -- and found out that it's 320 million cubic miles.

So, what were the earlier estimates? I'm on Slashdot => I did not RTFA.

Re:What were the earlier estimates? (0)

Anonymous Coward | more than 3 years ago | (#32271004)

I did RTFA and did not see the earlier estimates.

Re:What were the earlier estimates? (2, Informative)

mister_playboy (1474163) | more than 3 years ago | (#32271040)

The article specified the earlier (but still recent) estimate with weird units:

320 million cubic miles + 5 Gulf of Mexicos

and

320 million cubic miles + 500 Great Lakes(s)

Re:What were the earlier estimates? (3, Funny)

Jenming (37265) | more than 3 years ago | (#32271060)

I wonder if you need to correct for the oil if you use the Gulf of Mexico units. Or perhaps it just counts for that date.

Re:What were the earlier estimates? (2, Interesting)

maxume (22995) | more than 3 years ago | (#32271138)

1 cubic mile is about 26 billion barrels.

Re:What were the earlier estimates? (3, Funny)

miggyb (1537903) | more than 3 years ago | (#32271158)

How many Libraries of Congress would that be?

Re:What were the earlier estimates? (3, Funny)

Scaba (183684) | more than 3 years ago | (#32271598)

How many Libraries of Congress would that be?

About 12 million football fields worth.

Re:What were the earlier estimates? (1)

tverbeek (457094) | more than 3 years ago | (#32271612)

I'm an American; I need that expressed in football fields.

Re:What were the earlier estimates? (2)

hey! (33014) | more than 3 years ago | (#32271986)

I'm an American; I need that expressed in football fields.

Oddly enough, so does the rest of the world, although their "football field" has an area of 71.4 ares instead of 53.51 ares.

Re:What were the earlier estimates? (1)

maxume (22995) | more than 3 years ago | (#32272036)

Most of America measures their football fields in ises, not ares,

Re:What were the earlier estimates? (1, Informative)

Dthief (1700318) | more than 3 years ago | (#32271890)

Its ok, its from FoxNews, so you are better off not RTFA

Re:What were the earlier estimates? (1)

T Murphy (1054674) | more than 3 years ago | (#32272166)

The article says the difference is about 500 times the volume of the great lakes, which have a volume of 5,439 mi^3 [epa.gov]. That would be about 2.5 million cubic miles, or a bit less than a 1% change between the old and new estimates.

Evaporation? (3, Interesting)

cytoman (792326) | more than 3 years ago | (#32270962)

Do they consider the effect of evaporation? Earth loses some of its atmosphere to space constantly and it's not too improbable that some water vapor is also lost in this way...

Re:Evaporation? (1)

geekoid (135745) | more than 3 years ago | (#32270980)

What? what water bleeds into space?

Re:Evaporation? (2, Interesting)

Narcocide (102829) | more than 3 years ago | (#32271000)

Don't panic, it's not very fast, but we DO need to encase it, ourselves and the sun in a giant Dyson Sphere [wikipedia.org] soon to mitigate the problem.

Re:Evaporation? (1)

cytoman (792326) | more than 3 years ago | (#32271034)

Better believe it - what with anthropogenic global warming and all...the water will all just boil away and earth will become one giant desert :-(. Just give it enough time, that's all.

Re:Evaporation? (1)

cytoman (792326) | more than 3 years ago | (#32271058)

Isn't that why Mars is dry?

Re:Evaporation? Bleeding off Hydrogen (3, Informative)

thms (1339227) | more than 3 years ago | (#32271234)

Yes, IIRC by the same mechanism Venus has a lot of relatively heavier elements (Carbon, Oxygen, Sulfur), but barely any Hydrogen if you compare it to Earth and count the oceans as part of the atmosphere.

Water (gas) is split by solar radiation higher up, and the light hydrogen is carried upwards, and some of these particles bump into each other and often enough these bumps add up to escape velocity for one particle. Supposedly solar winds also play a significant role, and as Mars and Venus don't have a magnetic field anymore to protect them, over the eons all the hydrogen was lost. One more factor for the Drake Equation!

Re:Evaporation? (0)

Anonymous Coward | more than 3 years ago | (#32272240)

Earth has an order of magnitude more mass than Mars. This assists with the retention of our atmosphere.

Re:Evaporation? (1)

pj81381 (1703646) | more than 3 years ago | (#32271818)

From the article:

The trend toward a progressive lowering of volume estimates is not because the world's oceans are losing water. Rather, it reflects a greater ability to locate undersea mountain ranges and other formations, which take up space that would otherwise be occupied by water.

Also, we might be in trouble if we were losing enough atmosphere to lose 500 Great Lakes worth of water in 30-40 years, especially considering there isn't much water vapor in the upper atmosphere, due to low temperature.

Re:Evaporation? (1)

phantomfive (622387) | more than 3 years ago | (#32271844)

I was thinking the same thing. We should really start a project to refill the oceans, based on how the oceans have shrunk and are evaporating. We should give this project a catchy name.....say, global warming?

Re:Evaporation? (4, Interesting)

w0mprat (1317953) | more than 3 years ago | (#32272222)

While it's true we lose some gas at the top of our atmosphere, earth is probably sufficiently large that we have a net growth due to meteorite bombardment. (By every measure I've heard of the earth is supposedly getting heavier). We may take on extra H2O from water ice in meteroids?

Re:Evaporation? (0)

Anonymous Coward | more than 3 years ago | (#32272524)

yes they did.
  From TFA: "The trend toward a progressive lowering of volume estimates is not because the world's oceans are losing water. Rather, it reflects a greater ability to locate undersea mountain ranges and other formations, which take up space that would otherwise be occupied by water."

And soon ... (0, Flamebait)

jamesl (106902) | more than 3 years ago | (#32270986)

And soon it's average depth will be 2.29 miles plus a foot or two, according to the IPCC.

Re:And soon ... (0)

Anonymous Coward | more than 3 years ago | (#32271174)

Yeah you know me! I'm down with the IPCC!

I wonder (0, Redundant)

geekoid (135745) | more than 3 years ago | (#32271018)

After reading the article (SHOCKING!)
I wonder if they could get ships to carry a device to collect depth and undersea mountain patterns and then aggregate the data later. Might be cheaper the 2 billion dollars.

Re:I wonder (2, Insightful)

rm999 (775449) | more than 3 years ago | (#32271324)

Did you read the first sentence?
"Using lead weights and *depth sounders*"

That is what they used to do. But it only samples a tiny bit of the ocean and is biased towards certain parts of the ocean, like shipping channels. As the article says, the depth of the ocean is not very smooth, so non-global estimates won't be accurate.

The real question.. (0)

Anonymous Coward | more than 3 years ago | (#32271024)

is whether they calculated the mean depth by assuming the oceans are flat with varying depth, or assuming it is spherical.

Re:The real question.. (1)

Garble Snarky (715674) | more than 3 years ago | (#32271448)

That doesn't really make any sense at all

Re:The real question.. (1)

McGiraf (196030) | more than 3 years ago | (#32272352)

Yes it does, if you change depth for volume in the sentence, and change some other words, remove some, add some, and change the order of the words.

the floor of the ocean has a smaller radius than the surface

Re:The real question.. (1)

mosb1000 (710161) | more than 3 years ago | (#32272384)

He's talking about the difference between assuming a spherical earth and a flat earth. It effects volume-related calculations.

Is that so hard? (0)

Anonymous Coward | more than 3 years ago | (#32271042)

At only 2.29 miles mean depth, you'd think BP could have found a shallower place to drill.

Re:Is that so hard? (4, Insightful)

DamienNightbane (768702) | more than 3 years ago | (#32271230)

There are tons of places off the coasts that are far shallower with lots of oil. They couldn't drill in those spots because the government wouldn't let them, thus forcing them to drill in the more risky deep ocean wells where gas likes to freeze and make your rigs explode.

Government didn't force them to drill there (1, Funny)

Anonymous Coward | more than 3 years ago | (#32272722)

To be fair, government didn't force them to drill there. It disallowed drilling in some locations so the company evaluated risks and decided to drill there.

Now that we know how well they do evaluating risks, I am rather pleased that government put some restrictions on their drilling. Because it is clear that they choose a risk of a massive catastrophe if they believe that there are profits involved and can't be trusted in this matter. I just wish that the government(s) would have put much more restrictions in place.

Wait, so what's your point? (1)

Pirate_Pettit (1531797) | more than 3 years ago | (#32271048)

From Article: It would take 10 ships 20 years to measure all the ocean-floor depths with an echsounder, according to published U.S. Navy estimates.

"That would come to about $2 billion," Smith says. "NASA is spending more than that on a probe to [the Jupiter moon] Europa."

Right, it costs more to send something into space. There are a lot of scientific pursuits less expensive that space travel. I'm confused...what's this comparison trying to say?
If the quote had been "Nasa is spending less than that on a probe....", then it would have offered commentary on how prohibitively expensive the project is (if true). Instead, it costs less to image the earth than image Europa. What are they saying?

Re:Wait, so what's your point? (2, Insightful)

AuMatar (183847) | more than 3 years ago | (#32271240)

The point is that accurate information about the Earth's oceans would be more valuable, and we're spending that kind of money to image another planetrary body. I'm not in 100% agreement, but his argument is sound.

How about some metric figures? (5, Informative)

Edisman (726822) | more than 3 years ago | (#32271054)

For all you metric fans out there, the volume 320 × 10^6 cubic miles is approx. 133.4 × 10^7 cubic km with an average depth of 3.69 km.

Re:How about some metric figures? (1)

melikamp (631205) | more than 3 years ago | (#32271124)

My measurement system is based on furlongs, fortnights, and frags, you insensitive clod.

Re:How about some metric figures? (5, Funny)

Red Flayer (890720) | more than 3 years ago | (#32271142)

For all you metric fans out there, the volume 320 × 10^6 cubic miles is approx. 133.4 × 10^7 cubic km with an average depth of 3.69 km.

Yes, but that's meaningless to most people, it's a VLN without context. For all you fans of real, visceral numbers you can relate to, that volume (1.33 x 10^9 km^3) is approximately equal to the amount of water in the earth's oceans.

Hope that helps you to understand the magnitude of the number. Glad to be of service.

Re:How about some metric figures? (0, Redundant)

golden.radish (1459385) | more than 3 years ago | (#32271772)

"... Yes, but that's meaningless to most people ..." inside the United States.

Seriously... miles? In 2010? You know there's less than 350 million of you, right? How about you take one of those trillion dollars you spend on being the world police and catch up with the rest of world by switching to metric.

Re:How about some metric figures? (2, Informative)

BerryMadness (1591615) | more than 3 years ago | (#32272118)

Seriously... miles?

I know. Everyone knows that you are supposed to use miles for length and gallons for volume.

Re:How about some metric figures? (1)

4D6963 (933028) | more than 3 years ago | (#32272056)

Another perhaps more meaningful way to put it is that it's the same volume as a sphere with a diameter of 1366 km (roughly the size of Iapetus [wikipedia.org]), knowing that the Moon has a diameter of 3476 km, which means a sphere with 16.5 less volume than the Moon.

Re:How about some metric figures? (1)

ras (84108) | more than 3 years ago | (#32272110)

So, the oceans contain roughly 1 cubic mega meter of water. That is an easy number to remember.

Oh, how I love metric.

Re:How about some metric figures? (1)

StikyPad (445176) | more than 3 years ago | (#32272196)

Sorry, that's too vague and 1 EO (Earth's Oceans) sounds small.

  • Olympic Swimming Pools: 5.32e14 total -- 79,435.5 per person* (depending on pool depth)
  • Oil Barrels: 8.36544833e18 total -- 1,249,086,310 per person
  • cups: 5.62158127e21 total -- 839,385,998,000 per person

* Using World Bank estimate for 2008: 6,697,254,041 people

Re:How about some metric figures? (0)

Anonymous Coward | more than 3 years ago | (#32271170)

And for us fans of significant digits, that's approximately 130 × 10^7 cubic km...

Re:How about some metric figures? (1)

suomynonAyletamitlU (1618513) | more than 3 years ago | (#32272108)

Or for fans of scientific notation, 1.3 × 10^9 cubic km. Or 1.3 billion cubic km, if you prefer. Or 1.3 cubic megameters, not that anyone actually would find that useful, although I find it fascinating.

I don't really know why you and GP put it in terms of 10^7. Putting it in terms of 10^6 makes a little sense, since it equates to "millions". 130 ten-millions is a strange metric (no pun intended).

Not that any of this matters or anything.

Re:How about some metric figures? (1)

OctaviusIII (969957) | more than 3 years ago | (#32271678)

And to us fans of "classic" metrics, we have:

5.34 x 10^14 olympic sized swimming pools (534 trillion)

1.24 x 10^13 Libraries of Congress (12 trillion)

4.475 x 10^19 firkins (45 quintillion)

And the depth is equivalent to 18.32 furlongs or 8.2 Empire State Buildings. You're welcome.

Statistics brought to you by . . . (0)

Anonymous Coward | more than 3 years ago | (#32271094)

BP

Comment will be scored -1 Flamebait (1)

Snarkalicious (1589343) | more than 3 years ago | (#32271168)

for suggesting climate change deniers will jump all over this as proof of their POV in 3...2...1...

Re:Comment will be scored -1 Flamebait (0)

Anonymous Coward | more than 3 years ago | (#32271418)

And what about human-induced climate change deniers?

Damn it. Be scientific (0)

Anonymous Coward | more than 3 years ago | (#32271210)

320 million cubic miles = 1.33381818 × 10^18 m3

For fuck's sake, use scientific SI units regarding scientific topics.
The same imperial, US-only nonsense unit have cost a NASA probe...

Re:Damn it. Be scientific (0)

Anonymous Coward | more than 3 years ago | (#32271514)

Alternatively you could say that the rest of the worlds insistence on SI units cost NASA a probe. Or that, since the equipment actually used to produce the probe was marked in US units, a conversion was necessary at some point, and the operating software was probably a reasonable place for that conversion in spite of the result.

There's a tangible benefit to using the same system of units everywhere. You could reasonably debate about whether or not it's worth the switch. But there's very little inherent benefit to SI units, and certainly not enough to bother with all the hassles of converting -- just ask NASA about the dangers of trying to use two sets of units on the same project.

Re:Damn it. Be scientific (-1, Troll)

Anonymous Coward | more than 3 years ago | (#32272232)

Typical Amerio-centric head-in-the-sand, the only-reality-is-my-reality bullshit. You realize that you're already using SI units in multiple places in your country? Check food packaging. It's there. It's there in other places too. So you're already using two systems, and it's already been proven that using two sets of units has hazards. "Just ask NASA."

Paging Captain Nemo (3, Funny)

schmidt349 (690948) | more than 3 years ago | (#32271216)

2.29 miles isn't even 1 league! I thought the ocean was 20,000 leagues deep!

Re:Paging Captain Nemo (1)

szark (1066530) | more than 3 years ago | (#32271280)

A common misconception. The "20,000 Leagues" refers to the distance the Nautilus travels under the sea, not the depth.

Re:Paging Captain Nemo (0)

Anonymous Coward | more than 3 years ago | (#32271306)

That number references the distance traveled, not the depth.

Re:Paging Captain Nemo (0)

Anonymous Coward | more than 3 years ago | (#32271322)

http://snltranscripts.jt.org/93/93qleagues.phtml

Confirmation? (1)

pclminion (145572) | more than 3 years ago | (#32271218)

Could these numbers be confirmed by gravimetric measurements of the tides? The moon, sun, and to a very small extent the planet Jupiter, raise tides in the ocean and induce a gravitational moment. It seems like we could measure that and use it to approximate the mass of the oceans and therefore their volume, though off the top of my head I'm not sure about the details.

Mark my words (1, Funny)

Bemopolis (698691) | more than 3 years ago | (#32271256)

Fox News will retract this story once they realize that it increases the percentage of the ocean filled with oil. And then denigrate the scientists involved as Marxists.

Where do that start measuring? (2, Interesting)

Itninja (937614) | more than 3 years ago | (#32271326)

Do they include the extreme edge of the oceans (i.e. beaches) where the 'depth' is only a few millimeters? Or do they go out to sea a standard distance before they start measuring?

Re:Where do that start measuring? (0)

Anonymous Coward | more than 3 years ago | (#32271490)

The area of the shallow region is small compared to the total area, so this would not give a large effect.

Global warming? (2, Funny)

sharkey (16670) | more than 3 years ago | (#32271550)

We must stop global warming!! Our oceans are getting smaller, we, um, need to, uh, what?

If earth were a perfect sphere... (0)

Anonymous Coward | more than 3 years ago | (#32271644)

I have a challenge for you all: if the earth were a perfectly smooth sphere but with the same volume of dirt/rock as it is now, how deep would the ocean covering its surface be? (Assume no gravitational effects of the moon or whatever - just a sphere of dirt/rock, and an ocean of equal depth everywhere.)

Fox News (1)

Hadlock (143607) | more than 3 years ago | (#32271690)

I never thought I'd see the day when /. links to fox news.
 
It's a fairly well written article though. I'd say it's head and shoulders above anything they've linked to on Tom's Hardware, but that's not saying much.

Smaller than expected. (3, Insightful)

fahrbot-bot (874524) | more than 3 years ago | (#32271880)

Having lived their entire lives without seeing the ocean, two old women take a trip to the Pacific coast. Upon arriving on the beach, one looks out toward the horizon and says to the other, "That's funny, I thought it would be bigger."
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