Spaceship Earth: Our oasis in the emptiness of space.

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Spaceship Earth Our oasis in the emptiness of
space.
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15 20 C
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Our star, the Sun, has a profound influence on
the climate on Earth. Here, a solar flare is
shown, as well as granules on the Suns surface
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The solar constant (the amount of radiation that
reaches Earth) varies over the 11 year cycle of
solar magnetic activity (X-ray view of 1991-1995
solar cycle).
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1645 1715 The Maunder Minimum in Sun Spots
Did it affect Earths climate?
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Rise in the amount of atmospheric CO2, measured
on Mauna Loa. Summertime lows result from uptake
of CO2 by vegetation.
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Temperatures and amounts of atmospheric CO2 and
CH4 during the past 4 glacial-interglacial
cycles. The present-day levels of CO2 and CH4
(dashed lines) are higher than anytime during the
past 150,000 years!
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Layers of Earths atmosphere
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Southern hemisphere ozone (O3) hole
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Probable cause of ozone depletion in the
stratosphere

• Chlorofluorocarbon (CFC) refrigerant gases were
  introduced in the early 1930s by General Motors
  engineers seeking a replacement for hazardous
  materials used in refrigeration such as sulfur
  dioxide and ammonia. The use of CFCs has
  experienced dramatic growth, for air conditioning
  and refrigeration equipment, but also in
  industrial applications, including
• Propellant for aerosol cans
• Blowing agent for insulating foam
• Foam padding in furniture
• Halon fire extinguishers
• Automotive air conditioning
• Highly evaporative cleaning solvents
• Inhalers for asthma sufferers.

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Tracking El Nino in the Pacific using satellites
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Global distribution of aerosols throughout the
year
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More hurricanes? Hurricane Floyd and North
Carolina Flooding September 7 19, 1999
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Replica of a Chinese seismograph from 132
AD. The original was 1.8 m in diameter.
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Schematic of the functioning of the ancient
Chinese seismograph
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In an earthquake, P waves arrive first, S waves
second, and L waves last
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Typical seismogram of a major earthquake
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Seismic waves from natural or man-made
earthquakes can be used to study and decipher the
structure of the interior of Earth. S waves do
not travel through liquids, indicating that the
outer core of Earth is liquid.
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Relationship between the thermal gradient (i.e.,
the increase in T with depth) and the melting
point of silicates (mantel) and iron (core) as a
function of increasing pressure in Earth with
depth. Since the melting point of iron at the
pressures between a depth of 2,900 and 5,200 km
in Earth is below the temperature at these
depths, the iron in the outer core must be
molten (liquid).
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Summary