According to a Greek legend, the sea god Poseidon placed the figure of <a href="/the_universe/Constellations/circumpolar/cassiopeia.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">Cassiopeia</a> among the stars. It is said that Cassiopeia has a ridiculous upside-down position to punish her for having been pretentious.<p><small><em>Image courtesy of 1995 Visual Language (c). All rights reserved.</em></small></p><p>Something on Earth is always burning! NASA's Earth Observatory tracks wildfires across the world with <a href="http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOD14A1_M_FIRE" target="_blank">maps available for viewing</a> from 2000-present. Some wildfires can restore <a href="/earth/ecosystems.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">ecosystems</a> to good health, but many can threaten human populations, posing a natural disaster threat.</p>
<p>Check out the materials about natural disasters in <a href="/earth/natural_hazards/when_nature_strikes.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">NBC Learn Videos</a>, and their earth system science connections built up by the related secondary classroom activities.</p><p><small><em>NBC Learn</em></small></p>How did life evolve on <a href="/earth/earth.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">Earth</a> during the <a href="/earth/past/Archean.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">Archean</a>, when the <a href="/sun/sun.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">Sun</a> was about 25% weaker than today?  The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">greenhouse</a> gas concentration was the same as today.  <a href="http://www.manchester.ac.uk/aboutus/news/display/?id=10798">Researchers</a> studying the <a href="/physical_science/physics/atom_particle/isotope.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>An image of Hurricane Sandy taken by the GOES-13 satellite on October 28.  This category 1 <a href="/earth/Atmosphere/hurricane/hurricane.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">hurricane</a> was huge, spanning a horizontal distance of about one-third the US continental landmass.  The storm came onshore in New Jersey, and gradually moved northeast.  The storm disrupted the lives of tens of millions in the eastern US, doing billions of dollars in damage, resulting in over 30 deaths.  Visit the National Hurricane Center's webpage on <a href="http://www.nhc.noaa.gov/">Hurricane Sandy</a> for details.<p><small><em>Image courtesy of NASA</em></small></p>Scientists at the University of Michigan have found that <a href="/earth/polar/cryosphere_permafrost1.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">permafrost</a> in the <a href="/earth/polar/polar_north.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">Arctic</a> is extremely sensitive to sunlight.  Exposure to sunlight releases carbon gases trapped in the permafrost, including <a href="/earth/climate/earth_greenhouse.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">climate-warming</a> <a href="/physical_science/chemistry/carbon_dioxide.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">carbon dioxide</a>, to the <a href="/earth/Atmosphere/overview.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">atmosphere</a> much faster than previously thought.<p><small><em>George Kling, The University of Michigan</em></small></p>Sinkholes are <a href="/teacher_resources/main/frameworks/esl_bi8.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/earth/Water/carbonates.html&dev=1/earth/Atmosphere/moons/triton_atmosphere.html">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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