Current Events

  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

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    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.
  • Massive Tornado Outbreak on Tornado Alley
    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Io...Read more

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    Massive Tornado Outbreak on Tornado Alley

    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Iowa, Illinois and Missouri. On May 20th, a massive tornado struck Moore, Oklahoma, devastating communities - destroying over 100 homes and hitting two elementary schools and a hospital - with many casualties and deaths. Our thoughts are with our friends and colleagues suffering from these storms. For more on the May 20th storms, see the NOAA Storm Prediction Center Storm Report.
  • 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 Interior and Surface

Earth, the largest and densest rocky planet, was formed about 4.5 billion years ago. The Earth's interior is divided into four layers, which is typical of rocky planets. Each layer has different characteristics and is made of different elements and minerals.

There are many different types of features on Earth’s surface due to the complexity of our planet. The surface is unique from the other planets because it is the only one which has liquid water in such large quantities. Water forms some features of Earth's surface such as rivers, oceans, beaches and lakes. Other surface features, such as mountains, earthquakes and volcanoes, are formed when large pieces of the Earth’s outer layer move slowly by plate tectonics.

Bison roaming on mixed grass prairie - a type of <a
  href="/earth/grassland_eco.html&dev=1">grassland</a>
  - at Wind Cave National Park (U.S.).  Over one quarter of the Earth's surface
  is covered by grasslands. Grasslands are found on every continent except <a
  href="/earth/polar/polar_south.html&dev=1">Antarctica</a>,
  and they make up most of Africa and Asia. Grasslands develop where there
  isn't enough rain for <a
  href="/earth/forest_eco.html&dev=1">forests</a>
  but there is too much rain for <a
  href="/earth/desert_eco.html&dev=1">deserts</a>.
  Grasslands are filled with - you guessed it - grass.<p><small><em>        National Park Service</em></small></p>Rainforest vegetation on the Caribbean island of Dominica.  <a href="/earth/rainforest.html&dev=1">Tropical
  rainforests</a> are home to thousands of species of animals, plants, fungi and
  microbes. Scientists suspect that there are many species living in
  rainforests have not yet been found or described. Rainforests get their name
  because they receive a lot of rain - an average of 80 inches (203 cm) a year!<p><small><em>     NBII Digital Image Library - Randolph Femmer, photographer</em></small></p>This is the Barringer Meteor Crater in Arizona. The diameter is 1.2
  kilomters, and it is 49,000 years old. Compared with other planets, <a
  href="/earth/Interior_Structure/crater.html&dev=1">impact
  craters</a> are rare <a
  href="/earth/Interior_Structure/surface_features.html&dev=1">surface
  features</a> on Earth. There are two main reasons for the low number of
  craters. One is that our <a
  href="/earth/Atmosphere/overview.html&dev=1">atmosphere</a>
  burns up most <a
  href="/our_solar_system/meteors/meteors.html&dev=1">meteoroids</a>
  before they reach the surface. The other reason is that Earth's surface is <a
  href="/earth/interior/plate_tectonics.html&dev=1">continually
  active</a> and erases the marks of craters over time.<p><small><em>D. Roddy and LPI</em></small></p>The most majestic of the volcanoes are composite volcanoes, also
  known as strato-volcanoes. Unlike the <a
  href="/earth/interior/shield_volcanos.html&dev=1">shield
  volcanoes</a> which are flat and broad, composite volcanoes are tall,
  symmetrically shaped, with steep sides, sometimes rising 10,000 feet high.
  They are built of alternating layers of <a
  href="/earth/interior/lava.html&dev=1">lava</a>
  flows, volcanic <a
  href="/earth/interior/ash.html&dev=1">ash</a>,
  cinders, blocks, and bombs.  This is a photo of Mt. Cotopaxi in Ecuador.<p><small><em>The U.S. Geological Survey</em></small></p>Shortly after 5 am on the 18<sup>th</sup> of April in 1906, most people in
  San Francisco, CA were awoken by a sudden jolt.  The Earth shook violently in
  a strong <a
  href="/earth/geology/quake_1.html&dev=1">earthquake</a>.
  It lasted for only about a minute, but caused a lot of damage which destroyed
  much of the city. This photograph was taken just after an earthquake and
  fires had ravaged the city.<p><small><em>                                                    National Archives Still Picture Records Section, Special Media Archives</em></small></p>Sinkholes are <a href="/teacher_resources/main/frameworks/esl_bi8.html&dev=1">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/earth/Water/carbonates.html&dev=1">limestone</a>, leading to collapse of the surface.  Hydrologic conditions such as a lack of rainfall, lowered water levels, or excessive rainfall can all contribute to sinkhole development. On 2/28/2013, a sinkhole suddenly developed under the house outside of Tampa, Florida, leading to the tragic death of its occupant, Jeff Bush.<p><small><em>Image courtesy of Southwest Florida Water Management District</em></small></p>

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