New Estimates Say Earth's Oceans Smaller Than Once Believed 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."
What were the earlier estimates? (Score:3, Interesting)
So, what were the earlier estimates? I'm on Slashdot => I did not RTFA.
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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? (Score:4, Funny)
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.
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1 cubic mile is about 26 billion barrels.
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Google has the exact amount of barrels...
1 (mile^3) = 2.62170749 × 10^10 oil barrels [google.com]
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Yes, and a trucker needs to correct for the weight of the smashed insects on the window when he puts his truck on the scales.
For each gallon of oil spilled in the ocean, there are more than 600 billion gallons of water.
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Re:What were the earlier estimates? (Score:4, Funny)
About 12 million football fields worth.
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328 million cubic miles was the old estimate.
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I'm an American; I need that expressed in football fields.
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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.
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I believe those are football pitches actually.
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Evaporation? (Score:4, Interesting)
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What? what water bleeds into space?
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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.
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Hah! I could gum through that cheap diamondillium Dyson Sphere with my dentures behind my back! What we need is my patented ultra hard Diamondium [theinfosphere.org]!
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Re:Evaporation? (Score:5, Informative)
earth will become one giant desert
Raise worms
Produce spice
Profit!
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Re:Evaporation? Bleeding off Hydrogen (Score:4, Informative)
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!
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Nice link, thanks. They still aren't sure exactly the method that caused Mars to lose its atmosphere, but that pages shows some interesting probabilities.
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Re:Evaporation? (Score:5, Interesting)
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I think they prefer to be called 'the Obese.'
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Troll? I *am* US-ian, you insensitive clod?
I was referring to the weight of the average US citizen. Sheesh... talk about a whoosh.
Well it was more volumous... (Score:5, Funny)
Well, it was more volumous. But all those sponges soaked up so much.
How about some metric figures? (Score:5, Informative)
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Multiply the miles figure by 8x8x8 to get your cubic furlong volume.
Re:How about some metric figures? (Score:5, Funny)
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.
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So, the oceans contain roughly 1 cubic mega meter of water. That is an easy number to remember.
Oh, how I love metric.
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Sorry, that's too vague and 1 EO (Earth's Oceans) sounds small.
* Using World Bank estimate for 2008: 6,697,254,041 people
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Well, if you put all the water after each other, it would reach from here to the moon and back. maybe that helps us grasp such a big number...
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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.
Nice try, but
In short, any earthling who thinks he c
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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? (Score:5, Insightful)
It wouldn't be so much of a problem to deal with your backward measurements, except you have so many of them: Furlongs, inches, yards, feet, leagues, gauges, links, rods, chains, fathoms, hands, nails, and who knows how many more. Why even your "mile" comes in geographical, international, survey, telegraph, tactical, and three different nautical flavours (admiralty, international, and US). An ounce of gold is heavier than an ounce of feathers, but a pound of gold is lighter than a pound of feathers. It's insane!
The really sad part of it all is that all your measurements are based on the metric standards anyways. So why not save your sanity and convert fully?
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To quote: "The U.S. system of units is similar to the British Imperial system.[4] Both systems derive from the evolution of local units over the centuries, as a result of standardization efforts in the United Kingdom; the local units themselves mostly trace back to Roman and Anglo-Saxon units."
And from the metric system article:
"The metric system is an international decimalised system of measurement, first adopted by France in 1791"
I am pretty sure our old outdated American system of units predates the metr
Re:How about some metric figures? (Score:4, Insightful)
The really sad part of it all is that all your measurements are based on the metric standards anyways. So why not save your sanity and convert fully?
You are really clueless if you can't think of all the obstacles. MPH and how you measure your fat ass or assess the temperature are the least of the concerns. There are also matters of "hard" vs "soft" conversion. A "soft" conversion would be taking a standard unit wrench set (1/16" increments, e.g.) and numerically translating that to metric values. Easy and it can be done exactly and it is 100% compatible in both directions. It is also 100% fucking stupid as it creates a 3rd tool standard that is identical to an existing standard in all but name only. Buying a metric set of tools is easy. Many sets in the states will have both. What is difficult is all the associated hardware you must work with. At our small company, we retire a machine after - ohhhhh - maybe 20 to 30 years of work. So the machines we just bought that aren't 100% metric or are mixed are likely to be that way for decades. Consider other areas like building codes specifying 6" of insulation or 2x4s (~1.5" x ~3.5"). Again, we don't want "soft" conversions but rather the "hard" conversions that share an existing standard. Going metric would involve at least approving whatever the European equivalents would be. I hope nobody dies because of it! All our air water electrical conduit is in inches. I have never even seen pipe or conduit options in a metric size - that I recall. So very much of the imperial system is ingrained into everything we do.
What would be nice is if the pro-metric crowd would address the tough issues, seek parity where equivalents can be used, and - lastly - realize that this is a 100 year project where the 'hearts and minds' are the last thing you need to worry about. You can sell people on simplicity but you need to make a good case for it. Lastly - and I always say this - if the pro metric crowd cared about standards, they would ditch the French language. The sooner it is dead, the better. We don't need it.
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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.
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Actually it would make more sense to use base units when expressing such large quantities in SI units, and to normalize the numeric scientific notation.
1.334 x 10^18 m^3
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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.
Paging Captain Nemo (Score:4, Funny)
2.29 miles isn't even 1 league! I thought the ocean was 20,000 leagues deep!
Re:Paging Captain Nemo (Score:5, Informative)
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Yes, Ted, that was the joke.
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20,000 leagues is all the way through the Earth and about a quarter of the way to the moon.
Well, I bet Jules Verne wanted to write a book like that before the editors waltzed all over him saying, "That's impossible! You should make it the distance traveled under the sea!" He had his revenge with the Apollo program. Oh yes.
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Confirmation? (Score:2)
"Just" 2.29 miles? (Score:2)
Erm, 12,000 feet is pretty damn deep water.
Insensitive clod! (Score:2)
Where do that start measuring? (Score:3, Interesting)
Global warming? (Score:2, Funny)
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Have Al Gore hop in the water at Coney Island and the global sea level will rise 26.58mm.
Fox News (Score:2)
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.
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Let me be the first to say:
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the ocean's volume — the product of area and mean ocean depth
Next week we'll have multiplication explained to us, I suppose.
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This is my favorite:
The trend toward a progressive lowering of volume estimates is not because the world's oceans are losing water.
Smaller than expected. (Score:4, Insightful)
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She used to be taller.
How much? (Score:2)
Re:Is that so hard? (Score:4, Insightful)
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Forcing them to drill?!
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What a pity they weren't forced to have some sort of fail-safe system that actually worked.
Or to put it another way for all the absolute-free-marketers: this oil spill sure ain't providing profits to the shareholders.
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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.
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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.
Re:I wonder (Score:4, Informative)
I know it's got the word, "sounder" in it, but the lead weights *are* the depth sounder, it's got nothing to do with sonar. A depth sounder is like a plumb line, except it's wet, and much longer.
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[citation needed]
I grew up with a boat, and our "sounder" was sonar. There's a reason why it's called a sounder...
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http://www.essortment.com/hobbies/depthsoundersh_secb.htm [essortment.com]
In past times, ascertaining the water depth involved a difficult process called "sounding," which was done by throwing a weighted line over the side in an attempt to find the bottom. This line, called a "lead line" was knotted in increments that allowed the user to measure the water's depth in feet or more commonly, in "fathoms" a nautical unit of measure equal to 6 feet. Using a lead line from a moving vessel was of course problematic, and subject to inaccuracies. The user had to stand on the bow of the ship or boat and toss the line, wait until the lead weight hit the bottom, and then haul in the line and count the number of knots that were submerged. All the while the vessel was still moving and the bottom contour could, of course, have already changed by the time the sounder called out the depth to the captain.
Today's electronic depth sounders have changed all of this. Depth sounders provide instant and continuously updated readings of the water depth as a vessel speeds along. Depth sounders work by the principle of "sonar." A sound signal is emitted from the bottom of the hull and this signal travels through the water until it reaches the bottom and then bounces back, to be picked up by the depth sounder's receiver. Since sound waves travel at a known rate, the depth can be determined by calculating the amount of time it takes for the sound waves to hit the bottom and return to the vessel. This is all done automatically and instantaneously by the instrument.
So it was called sounding before we had sonar, and it's just a coincidence that the term "sound" is involved.
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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
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Assume spherical oceans of uniform density.
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"A big enough box could hold the world" -- Carl Sanburg
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"To make a box big enough to hold the world from scratch, you must first invent the universe" - Carl Sagan
Re:I estimate (Score:4, Informative)
Re:I estimate (Score:5, Funny)
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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.
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It's still wrong.
No, it's not: 6.697 - 300 millions = 6.397
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
Yeah, you're right.
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No, it's not: 6.697 - 300 millions = 6.397
Hah. Ok, fair enough.
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* ducks *
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BPs job just got easier. (Score:2)
Of course, now that people will be able to fish for oil right off the pier, shouldn't oil prices go down?
BTW - 640g people should be enough for everyone.
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Re:I estimate (Score:5, Insightful)
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.
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According to Glenn Beck it would have been the Nazis...
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+1, insightful. Poster has demonstrated the use of base units, not derived units, and normalizing the scientific notation.
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Except that there isn't really any benefit to using SI over Imperial measurements
At least the most commonly used SI units were created specifically because doing calculations with them is far less error prone within the same unit (ie, cm to km as opposed to inches to miles) and the units themselves are based on environmentally sensical points (ie, 0 is the temperature at which water freezes (at standard pressure))
I am glad as hell I didn't have use imperial measurements in engineering.
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"Never mind the fact that SI units actually work in a sane, base 10 oriented way..."
Yeah, but that only matters to sane people...