Thursday, July 13, 2017

How Big?

The glacier that broke off Antarctica is:
  • Twice the size of Luxembourg and Samoa;
  • Approximately the same size as Delaware or Brunei;
  • Nine times the size of Singapore;
  • Four times the size of London and seven time that of New York City.
In other words, it's pretty big, or as Calvin Trillin might say, bigger than a carrot and a bread box combined.

19 comments:

  1. Of course, like an ice cube melting in a glass of water, this giant ice island won't raise the sea level. However, it got out of the way of ice sliding off Antarctica into the ocean, and that can.

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    1. I keep hearing that. But the ice in my afternoon cocktail sticks up above the surface of the brandy and sweet vermouth. When the cubes melt, doesn't the liquid from the above-surface parts of the cubes raise the level?

      If you think I am going to sit here and watch the cubes melt scientifically, you don't know me around Manhattans. I'll accept an expert explanation.

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    2. If someone offered you a "manhattan" the size of Delaware, would you refuse to participate in the experiment?

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    3. one representation says it is the equivalent of an eight mile diameter ice sphere.

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    4. That would keep a "manhattan" cold. How much brandy and sweet vermouth would Tom need to keep it from becoming diluted. You do the math!

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    5. Everybody's a comedian. A manhattan the size of Delaware wouldn't fit in a glass, so how could I lift it? If you can solve that problem, I'd participate.

      I still don't know why the ice that sticks up above the surface line doesn't raise sea level. I did notice this afternoon -- unscientifically -- that once the ice floats (meaning it isn't piled up from the bottom of the glass) it doesn't stand up as high.

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    6. Tom,
      When a certain amount of liquid water transforms into ice, it goes into a crystalline structure that forces it into a volume 11% greater than that of the liquid. That 11% sticks above the water at a certain level. But as it melts, you can think of the ice below the surface melting and shrinking in volume. The ice above the surface can be thought of melting and making up the difference. If this doesn’t help, I could try pictures.

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    7. OK, let's say I have a tumbler of water. I measure the water level on the side of the glass. Then I pour out half the water and freeze it. Then I dump the frozen part back in the glass (let's assume no evaporation, spillage or loss of mass). If the ice has more volume than the liquid water, won't it make the water level go up slightly until the ice melts?

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    8. Sounds right...Vulgar experience:

      Make chicken stock. Pour into a quart container. There is a smidgen extra. You can't waste it. You pour that in to and and put the top on the container--a little tight! When you retrieve the frozen container with the stock, the cap is pushed up in the middle where the stock has expanded, or... the top is cracked because there was too much extra and the force of the stock freezing has cracked the top of the container.

      Is there a technical term for over-topping the stock? Is it related to temperature changes in the Gulf Stream? And what about El Nino?

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    9. Take a glass water container with three pints of water.
      Mark the water level on the side of the glass container.
      Scoop out 1 pint of water.
      The water level goes down.
      Freeze the pint of water, no bubbles allowed, no cheating with a long ice cube that sits on the bottom, it has to float freely.
      Put it back in container.
      Water level comes back to where you marked it.
      Whether in ice form or liquid, the water displaces the same amount of liquid water.
      In ice form, the extra volume sticks up above the water level.
      Don't know about chicken stock. Beyond my pay grade. I'm a lousy cook.

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    10. OK, I get it.

      Margaret is talking about freezing ALL the liquid in a closed container with no air, in which case the volume DOES increase (hence busted stock lid).

      Similarly, if you forced your floating frozen pint down into the unfrozen two pint with a spatula, so that it was at the same level as the water, none of it sticking up, you would increase the volume in the container.

      None of which really is the problem with rising sea level.

      A frozen container of chicken stock can wreck your Tupperware container by expanding. But you could unfreeze it just a bit, slide it out of the wrecked container and put the frozen mass in a bigger container and refreeze.

      The problem occurs when your freezer goes on the blink, and your chicken stock melts and runs all over your kitchen floor. In that case, the fact that the volume of the frozen stock is greater than the volume of the melted stock isn't something you're interested in b/c you have a big mess to clean up.

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    11. Jean, you're an honorary fizzycist.

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    12. Haha! I am great with 8-year-old boy scientists. Give them $5 to ride their bikes to the gas station for as much diet coke and mentos as that'll buy them, and it gets fizzy! Then I showed them this and made them figure out how much coke and mentos they'd need to travel 250k to the moon. I didn't make them figure in the force needed to escape gravity. But I should have. https://m.youtube.com/#/watch?v=i-hXcRtbj1Y

      We also had an air powered rocket and Peeps to blow up in the microwave. Vinegar and baking soda is always a good time.

      And here's something fun to do if your mom isn't home:https://m.youtube.com/#/watch?v=Hibxz9_ZW18

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    13. OK, I am happy. In fact, the water in ice form does take up more space than it does in liquid form. And it has something to do with why milk, when left on the porch in freezing weather would push up the cap and look really weird sticking out of the bottle. I am talking now about the days of milk delivery, which coincided pretty much with the days of ice boxes.

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    14. We used to get milk delivered. Also had a fridge, but it had to be defrosted. Freezer the size of a shoebox. Man, you stayed the heck out of Mom's way when defrost day came around.

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    15. You are so right. What genius invented the frost-free frig?

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  2. I gather that oceanographers are waiting to see if that area refreezes or continues to break off.

    One of the concerns, as I understand it, is that if the ice shelf keeps "calving" and more fresh water pours into the ocean, sea levels rise, get warmer, and salt levels drop, and that changes the ocean's whole ecosystem.

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  3. It's Greenlands melting fresh water that poses a threat to the Atlantic overturning thermohaline circulation (ah luvs that kinda talk) sometimes called the Gulf Stream. The water goes north from around the equator, evaporation makes it saltier until somewhere south of Greenland, it sinks and goes back down to the equator and the cycle repeats. Pour fresh water from the Greenland melt in and the water doesn't sink and it slows down the conveyor belt, doing all kinds of mischief to climate and sea life. It's already slowed down.

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  4. Some of the size comparisons don't seem very meaningful.

    Recently I read a story comparing Qatar to Cleveland. I suspect it meant of the City of Cleveland. When I think of Cleveland I think of Cuyahoga County which is roughly bounded by the beltway. But that includes many inner suburbs. I don't have much of an idea of what Cleveland is like when one subtracts those suburbs. Then there is the Cleveland metropolitan area which includes outlying counties like my own Lake County. Leaves me with a confused picture of what Qatar might be.

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