Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
Earth Science Technology

New Research Suggests Earth's Mantle Might Be Hotter Than Anyone Expected (sciencealert.com) 162

schwit1 quotes a report from ScienceAlert: New data suggests that the upper parts of Earth's mantle are around 60C (108F) hotter than previously expected. The mantle is the layer between our planet's super-hot core and outer crust, and it plays an incredibly important role in things like earthquakes, volcanic eruptions, and tectonic shifts. But despite the impact the mantle has on our planet, scientists have always struggled to pinpoint its temperature, and new research suggests our previous estimates were off the mark. If the new estimates made by scientists at the Carnegie Institution of Science in Washington DC are verified, it would mean the mantle is melting shallower than previously expected, and it could change the way we predict earthquakes and volcanic eruptions. The new estimates are based on the fact that the Earth's upper mantle is more affected by the presence of water in its minerals than we've assumed in the past. One of the most common ways to measure the temperature of the upper mantle is to analyze lava emerging from mid-ocean ridges - an underwater mountain range where two plates meet and hot mantle is drawn up and partially melts. So to more accurately measure the temperature at which this would melt, the researchers, led by Emily Sarafian, have used a new technique to add a quantifiable amount of water into mantle samples through tiny particles of the mineral olivine. This allowed them to more accurately measure the melting point of peridotite under mantle-like pressures in the presence of known amounts of water. "Small amounts of water have a big effect on melting temperature, and this is the first time experiments have ever been conducted to determine precisely how the mantle's melting temperature depends on such small amounts of water," said one of the researchers, Erik Hauri. They found that the potential temperature of the mantle beneath the oceanic crust is on average around 60C higher than previous estimates - with some parts much hotter than that. "Our experimental results indicate that mantle potential temperatures along all ocean spreading centers are hotter than existing estimates," the team writes in Science.
This discussion has been archived. No new comments can be posted.

New Research Suggests Earth's Mantle Might Be Hotter Than Anyone Expected

Comments Filter:
  • In the article the Celsius to Fahrenheit converter seems to have failed.

    I'd be happy the day that Fahrenheit is passed on to history together with other obsolete forms of measurements with strange conversion factors.

    • Who cares. It's just a scale no different than celcius. Only difference is those who use it complain they cannot convert to F. Americans have the same problem vice versa. So what's your point?

      • Who cares. It's just a scale no different than celcius.

        If it's no different then just use metric and we avoid these stupid arguments every fucking time this primitive unit of measure get mentioned

        • Re: (Score:2, Interesting)

          by elrous0 ( 869638 )

          Fahrenheit is a much better system for measuring human weather temperatures. 0 degrees is dangerously cold for humans. 100 degrees is dangerously hot for humans. Celsius is only relevant if you happen to be water.

          And, as for people who argue that Celsius is somehow more scientifically objective than Fahrenheit, it's really not. Celsius is only based on the objective freezing and boiling points of water if you happen to be subjectively located on the surface of this particular little blue planet. So stop

          • All of the imperial units were designed to fit human scale. The foot, for one, began as the actual length of some king's foot. What our all-wise ancestors didn't realize is that their imperial units developed without being related to each other, the factor that makes life so much easier for metric users. Knowing that your one-liter soda bottle, if filled with water, weighs one kilogram, is one of the superpowers that French chefs make use of. Our recipes, meanwhile, are full of teaspoons and tablespoons and

            • by elrous0 ( 869638 )

              For the record, I'm fine with the metric system. I just don't think Celsius is a good system for measuring weather temperatures. If you routinely have to use negative numbers and decimal places for even typical weather conditions, your measurement system is not ideal for its purpose.

              • by angel'o'sphere ( 80593 ) on Saturday March 04, 2017 @03:14PM (#53976611) Journal

                It is absolutely ideal to to use negative numbers.
                At zero water freezes, below zero it is frozen: very important for drivers, planes/airports etc. or house owners who have to organize clearing of snow, Skiing/winter sports areas etc. or estimations how long it takes that lakes freeze over.

                Nothing can be simpler than having 0 at the freezing point of water.
                You are just not used to it.

                • Are you talking about salt water, pond water or distilled water? Because they all have different temperatures at freezing.
                  • I did not talk about water.
                    I talked about F and C, both are based on water. Which water the inventors used I leave to your imagination or to your reading skills. Hint: wikipedia.

                    Facepalm ... nitpicking at its finest, but just so dump and pointless.

            • by lgw ( 121541 )

              >quote>Knowing that your one-liter soda bottle, if filled with water, weighs one kilogram, is one of the superpowers that French chefs make use of. Our recipes, meanwhile, are full of teaspoons and tablespoons and fluid ounces that are hell to convert to each other.

              A pint's a pound the world `round.

              • by dryeo ( 100693 )

                Much of the world used imperial where a gallon was defined as 10 lbs of water holding 160 fluid ounces so a pint is 20 fl oz or 1 and a quarter pounds (at 67 degrees F IIRC)

                • by lgw ( 121541 )

                  The system where a "hundredweight" was 120 pounds? We pretend that never happened.

                  • by dryeo ( 100693 )

                    Yea, those Germans didn't seem to use a decimal system of counting way back. We're talking English Imperial where a hundredweight was 8 stone or a 20th of a proper ton of 2,240 lbs, though in N. America we use[d] the decimal ton of 2000lbs.
                    One of the problems is that we've had so many counting methods, do we use fingers or the gaps in between the fingers is one example with both having been used at one time and you must admit that base 8 makes a nice system.

            • by dryeo ( 100693 )

              In Imperial, a gallon weighs 10 pounds and contains 160 fluid ounces that weigh an ounce . 2 Imperial cups to a pint so a cup is 10 fl. oz and holds 10 ounces of water. Though here in Canada a cup is 8 fl .oz or 1/20th of a gallon and holds 16 tablespoons or 48 teaspoons.

              https://en.wikipedia.org/wiki/... [wikipedia.org]
              https://en.wikipedia.org/wiki/... [wikipedia.org]

          • In addition to the 0-100 F range being the temperatures a human can expect to encounter in the habitable portions of the planet where we live, the unit size is better too. 1 degree F is about what a human can perceive environmentally. So whole numbers convey just the right precision for forecasts, environmental settings, etc. Whereas with Celsius, forecasts, thermostat settings, etc, must be specified with decimal places, because 1 degree Celsius is too large and imprecise unit for day to day use. Again,

          • Fahrenheit is a much better system for measuring human weather temperatures.
            Complete nonsense, no it is not. It is only convenient for those who are used to use it. For everyone else it is complicated
            0 degrees is dangerously cold for humans. That is wrong. It is only -18 degrees in Celsius. It is cold if you are naked or not properly dressed.
            100 degrees is dangerously hot for humans.
            This is absolutely wrong. This is your body temperature. Every summer in Germany easily tops this temperature, no one is co

          • Fahrenheit is a much better system for measuring human weather temperatures.

            That's nice. Now how about all the other things temperature is used for?
            I agree though, Imperial units are great if you a goat herder from the 8th century. It's just that we've all moved on since then.

          • Fahrenheit is a much better system for measuring human weather temperatures.

            (1) that's a very arguable assertion. Having worked at temperatures from -30 (-22) to +48 (+122), I'm really unclear what your perceived benefit to using Floppyhat degrees is. Feel free to defend your assertion.

            (2) We're not talking about human-affecting weather.

      • by lgw ( 121541 )

        The difference is: Fahrenheit is part of the One True System of Measurement: the "go F yourself system."

        The base units in the go F yourself system are: Furlong Firkin Fortnight Fahrenheit and Faraday. Derived units such as Foot or Fathom are sometimes used as well. All units are abbreviated F for simplicity.

        All other systems of measure are clearly inferior, obsolete, outdated systems only used by weird mountain-folk in flyover country.

    • Re: (Score:2, Insightful)

      by ls671 ( 1122017 )

      Next; 10 hours in a day, 10 minutes in an hour and 10 seconds in a minutes? Minutes, seconds and hours are still around aren't they?

      You can evenly divide 12 sheep between 2,3,4 or 6 people. You can divide 60 sheep between 2,3,4,5,6,10,12,15,20,30 people. Not bad if you consider trying it with 10 or 100.

      These numbers were viewed as convenient back then. That's why we still buy eggs by the dozen; 360 degrees, 24 hours, etc.

      212F-32F is 180 which is 3*60 etc. etc.

      You should get used to old units, they constitut

      • Re: (Score:3, Funny)

        by Gussington ( 4512999 )

        You can evenly divide 12 sheep between 2,3,4 or 6 people. You can divide 60 sheep between 2,3,4,5,6,10,12,15,20,30 people. Not bad if you consider trying it with 10 or 100.

        I'll remember that next time I have exactly 12 sheep and a group of either 2,3,4, or 6 people to divide them among. Hopefully I won't have 5,7,8,9,10, or 11 people, or any number of sheep other than 12 or 60 or I'm screwed.

        This is why Imperial units got replaced, they are antiquated and make no sense in the 21st century.

      • by quenda ( 644621 )

        Next; 10 hours in a day, 10 minutes in an hour and 10 seconds in a minutes?

        Actually milli-days would be a great way to express time of day, rather than hours and minutes. A microday is around a tenth of a second, so good for stopwatches.

        It is a little like the queen of England speaking pretty good French. For them it a must, a sign of noblesse,

        Its mostly to distract us from the fact that the Royal Family are all German. Even the Greek one is really German.

      • Next; 10 hours in a day, 10 minutes in an hour and 10 seconds in a minutes? Minutes, seconds and hours are still around aren't they?
        Was tried. But considered inconvenient and dropped again.

        BTW, in Europe you buy eggs, by ten, or _half a dozen_ did not see a place where you could get a prepacked dozen eggs since 30 or 40 years. However everything you can buy per piece e.g. oysters you by per dozen, however in France you then get 13 oysters :D (just because you mentioned the Queen)

        360 degrees btw, we have bec

        • I was watching a youtube video from Australia yesterday and the guy was describing almost everything in inches and MPH. Same goes for a video from Scotland I saw yesterday (car and engine shows).
      • I want metric days! I could get so much more done if I had 100 hours to work with.
    • I'd be happy the day that Fahrenheit is passed on to history

      If you're under about 45, Fahrenheit has been dead your whole life ; if you're older than that then you might have been exposed to it in your youth and have some reason for wanting to nostalgically mention the dead units.

  • When someone tells you their model of the earth's temperature is predictive a century or two out.

    I mean it isn't as if the radiation profile emitted by the earth is determined by it's temperature /sarcasm.

    • However the time for temperatures to equilibrate is a lot longer than human time scales. When I'm drilling holes in the ground and lowering temperature probes into them (and then letting temperatures equilibrate for several days - we know this takes time), we can see the effects of pulses of rapid sedimentation 10 to 12 million years ago a mere 2km below the mudline (so, 5km+ below the drill floor) as depressions in the geothermal profile.

      Closer to the surface, exploration of deep caves in sub-arctic Canad

      • Once you get away from the first few hundred metres of the Earth's surface, heat transfer is sufficiently regular that you can predict the temperature at your depth of interest millennia in advance. (Unless something unexpected like a break through from a natural thermal spring happens. Which isn't very often.)

        Volcanic activity ?

        • You asked

          Volcanic activity ?

          Every area of volcanic activity that I've seen has precursory and post-activity thermal spring activity spread over a few tens of kilometres radius of the "centre" of activity, which itself can be of the order of ten km in diameter (I think Yellowstone is significantly bigger, but being foreign, I don't waste much time on it's details. We've certainly got volcanic centres 20 and 30km across here in Britain, though they've been mostly inactive for a few tens of millions of years.

  • I like how humans describe and imagine layers of the space they live in; the Earth mantle, the stratosphere, etc...

    We even have pictures with the "borders" between each layers depicted ;-)

    It's all in our heads really, there is no clear border between these layers, the Earth is just a mass with the center still warmer than the surface.

    • by Njovich ( 553857 )

      You should look up the 'core–mantle boundary' and be amazed. (Otherwise, sure, some of these layers are pretty arbitrary)

    • by tomhath ( 637240 )
      While the boundaries aren't distinct, different things happen in each layer so it makes sense to consider them individually.
    • It's all in our heads really, there is no clear border between these layers, the Earth is just a mass with the center still warmer than the surface.

      Contrary to Njovich [slashdot.org]'s suggestion, rather than looking anything up, why don't you go and do an undergraduate course in geophysics, including doing some practical work on measuring and interpreting seismic waves from your very own sledgehammer. Then you'd know just how clear the boundaries are.

      That's the great thing about science - you can just tell sceptics to g

      • by ls671 ( 1122017 )

        https://en.wikipedia.org/wiki/... [wikipedia.org]:

        This boundary is located at approximately 2891 km (1796 mi) depth beneath the Earth's surface.

        Brilliant: "approximately 2891 km", right. "Approximately 2900 km" would have sounded better...

        Still, it is an example of what I stated in my OP.

        On top of that, those guesstimates rely on technology that may seem retarded in a few centuries and nobody has ever been there to measure the layers ;-)

        And then:
        https://en.wikipedia.org/wiki/... [wikipedia.org]

        0–60 0–37 Lithosphere (locally varies between 5 and 200 km)
        0–35 0–22 Crust (locally varies between 5 and 70 km)
        35–60 22–37 Uppermost part of mantle
        35–2,890 22–1,790 Mantle
        210-270 130-168 Upper mesosphere (upper mantle)
        660–2,890 410–1,790 Lower mesosphere (lower mantle)
        2,890–5,150 1,790–3,160 Outer core
        5,150–6,360 3,160–3,954 Inner core

        Ooops, now the mantle has 4 arbitrary layers and there is no name for the 60-210km layer! I will call a meeting to add a layer to the mant

      • by ls671 ( 1122017 )

        I use science all the time but I take it with a grain of salt

        FYI: so did Albert Einstein otherwise, he would never have found anything...

        I suggest you read this:
        http://www.chriscappell.com/en... [chriscappell.com]

      • by ls671 ( 1122017 )

        Contrary to Njovich [slashdot.org]'s suggestion, rather than looking anything up, why don't you go and do an undergraduate course in geophysics, including doing some practical work on measuring and interpreting seismic waves from your very own sledgehammer. Then you'd know just how clear the boundaries are.

        What is the contrary of Njovich? Maybe you meant "contrarily"?

        Also, as a teenager, I use to work on seismics (Schlumberger) and I have also worked on oil rigs and punched 4 miles deep holes in the Earth crust. I might have been deeper than you have ever been...

        • by ls671 ( 1122017 )

          and we couldn't positively identify oil patches by seismics (using dynamite, not a sledgehammer), we just provided guesstimates. Some of what looked like oil patches turned out to be nothing; a dry hole.

          • As you'll know, 90% of wildcat wells come up dry - or to be more precise, uneconomic. From your comments, I gather that you ran the cables and set the geophones for the seismic crew, but didn't QC the data or interpret it. Important work - and why I'm perfectly happy to catch and process my own samples in amongst managing the other data collection aspects of drilling an exploration wildcat in 3km of water (with a 20-30% success rate, depending on oil prices a decade from now, and whether the Chinese want to
        • What is the contrary of Njovich?

          This is a language called "English". If you're an American, you might care to learn it one day.

          Maybe you meant "contrarily"?

          I meant precisely what I typed : I was saying something contrary to his position.

      • by ls671 ( 1122017 )

        In the end, I would like to state something:

        You never had a clue WTF you were talking about.

        Feels good to let myself go wild.

        Still, I would wish that you come to a point where you would smart up!

        Cheers, peace and love, John Lennon and all the rest for you and your siblings.

        • Feels good to let myself go wild.

          That would explain why you didn't get very far with Schlumberger.

          • by ls671 ( 1122017 )

            Again, you don't know WTF you are talking about. Neither do you know how far I got with anything.

            Just admit you are a regular, average, science groupie.

            Cheers,

  • To the Editors ... (Score:5, Interesting)

    by RoccamOccam ( 953524 ) on Saturday March 04, 2017 @08:54AM (#53975243)

    As an American Slashdot reader, for all science articles I suggest that you stop providing both metric and imperial units. Metric is fine with us. Really.

    If we need the conversion, we can do it in our heads. Most importantly, it will improve the signal-to-noise ratio in the comments by eliminating the ever-present unit-conversion threads.

    • Thank you. Excellent idea, but won't that kill the new slashdot business model?
    • Speak for yourself. There are a lot of people on this earth who grew up using the english measurement system and it is discriminatory (as well as misleading) to publish information that does not provide numbers in forms people can intuitively understand.

      What's next, would you start taking away the Libraries Of Congress unit too? Your path is slippery and evil.

    • by hey! ( 33014 )

      OK, without looking, how many ml is 1 gill, 15 dram?

    • Probably the most useful comment on this thread.
  • Obviously, this is the result of global warming, since mankind has always had a greater effect on the climate than we are willing to acknowledge.

    • They wrote that awkwardly. It's 108C more than they expected, which is probably, I dunno, thousands of C if the mantle is melting rocks and crap.

      So instead of being insanely hot, it is now extra crispy insanely hot. Or, 108 more than they thought.

      It is NOT 108F and suitable for a moderately warm bath, nor 108C and suitable for making tea if there is any water left in the pot that hasn't gone to steam.

  • How hot is it?
    It is hot enough to melt the hinges off the gates to hell.

    How hot is it?
    It is hotter than the tongue of your ex-wife.

    Next!

  • ...is global warming.

    • The Earth radiates 60mW/sq meter from the core.
    • ...is global warming.

      A young hippie waitress just told me the other day that global warming is just the Earth's way of healing, since killing us off is what it wants and how it will recover. If I had told her the mantle just got a hundred degrees hotter she probably would have thought I was agreeing with her.

  • measure the melting point of peridotite under mantle-like pressures

    I understand they need a correct value for mantle-like pressures in order to get mantle temperature. But how do we evaluate mantle-like pressures?

If God is perfect, why did He create discontinuous functions?

Working...