Current Events

  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.
  • Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 ...Read more

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    Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows

    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field. For more information about this study, see the press release from the European Synchrotron Radiation Facility.
  • Ocean Volcanic Rocks Contain Samples of Recycled Crust
    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials fr...Read more

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    Ocean Volcanic Rocks Contain Samples of Recycled Crust

    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature. Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now. For more information about these results, see the press release from the Carnegie Institution.

Compare Images of Antarctic Sea Ice Extent Side-by-side

The pictures below show sea ice around the South Pole. Click on the popup menus above the pictures to choose which pictures to look at. You can look at two pictures at once and compare them.

Try this:

  • compare the sea ice in February and September for the same year (like February 2000 and September 2000)
  • compare the sea ice in February for two different years (like February 1979 and February 2010)
  • compare the sea ice in September for two different years
  • click here if you want to look at sea ice in the northern hemisphere

Select a month:
... and a year:

Select a month:
... and a year:

The images are courtesy of the National Snow and Ice Data Center (NSIDC).

Sea ice builds up during the winter when it is cold. When is there the most sea ice? There is usually a lot of sea ice in early spring, right after winter ends, around September. Remember, in the southern hemisphere, summer and winter happen at the opposite times of year from the northern hemisphere!

Over the summer, when it is warm, the sea ice melts. When is there the least sea ice? Since a lot of ice melts in the summer, there is usually much less sea ice in early fall around February, right after the end of summer.

The pink line in the pictures shows where the edge of the sea ice is, on average, in that month. Compare the edge of the ice in 1979 to the pink line. Now compare the edge of the ice in 2010 to the pink line. Do you see any difference?

Click here to see a movie of changes in sea ice over seven years (2002 to 2008). Watch how the ice melts in the summer and freezes and grows in the winter.

If you want to see more pictures of sea ice, go to the NSIDC web site to:

Last modified October 8, 2010 by Randy Russell.

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