Tides_BiancaM by shuifanglj


									 Add Earth, moon, and sun,
  then mix in the ocean.

Tides and how
  they work
       By: Bianca Maddox
          What are Tides?
• Tides are the rise and fall of the ocean.
  The force of tides affect objects on
  Earth, the atmosphere, and Earth itself.
  Tides are caused by the difference in
  strength of gravitational forces at
  different points on Earth. This involves
  the Earth, moon
  and the sun.
       How Tides Work
• Tides are
  caused by the
  force, which
  causes water
  to bulge on
  both sides of
  the Earth.
     Gravitational Forces
• The gravitational forces are the
  strongest for areas directly below
  the moon and on the opposite side
  of the Earth. The moons
  gravitational force causes the
  water to bulge on those sides of
  the Earth.
       Lunar and Solar Tides
• The sun has smaller tides than a lunar one.
  The moon and sun together will create
  spring and neap tides. Spring tides are
  very high and low tides, which occur when
  the Sun and Moon are on opposite sides of
  the Earth.                       Neap
  tides are                         the
     opposite.                        They are
     very low                      high tides
  and low                          low tides.
Diagram of Spring and Neap
             Bay of Fundy

• The Bay of Fundy is a place were the
  highest tides occurs. The tides can raise
  up to 50 ft. The time between high and
  low tides is 6 hrs. and 13 min. There are
  different phenomenon's for which the
  tides occur: tidal bores, rapids, and
  horizontal tidal effects.
Tidal Bores at Fundy
          • Tidal bores are
            when tides meet.
            This creates
            three high waves
            and wild rapids.
            The tides can
            cause whirlpools,
            rapids, and tidal
Horizontal tidal effects
            • Horizontal tidal
              effects cause the
              tide to sink back
              three miles. Since
              the bay is
              shallower and
              narrower near the
              upper part, the
              water rises
   Importance of measuring sea
• The importance of
  measuring sea level is
  to measure the
  height of everything
  on land. Mt. Everest
  is an example. It is
  also important
  because you know
  when the ocean is
  rising or falling, like
  for tides.
Measuring Sea Level

        • The sea level is
         measured by time
         gauges, which is a 1
         ft. in diameter pipe
         with a small hole
         between the
         Satellites are used
Difficulty with measuring sea level

• The difficulty with measuring sea level is
  the the sea is always moving. The water
  level is changed every second by waves,
  hours by tide, week by the change in orbit
  of the Earth and other planets, then by
  year because the ocean rises 2 mil per
            Global Warming

• Global warming is causing the temperature to
  rise. The temperature has risen 1/2 degrees C
  in the past 100 years. That is not the only
  thing that has risen, the sea level has rose 6
  to 8 inches in the last century.It is predicted
  that in 2100, the ocean will rise 50 cm.
Melting of Polar ice caps
            • The temperature
              rise is causing the
              icebergs to melt.

            • Icebergs are chunks
              of glaciers that have
              broke off.
            • The higher
              temperature is what
              is weakening the
Melting Places
      • Antarctica carries 90%
        of the World’s ice. If
        all the ice melted,
        ocean would rise 200
      • If North Pole melted,
        no change in sea level.

      • If Greenland melted,
        there would be a 20 ft
        increase in sea level.
         Tidal Waves-Tsunami
• Tidal waves are very high ocean waves that
  are caused by the sudden movement of
  water. Such as an underwater earthquake,
  undersea landslide, and a meteor or
  asteroid strike. Tidal wave is not a good
  expression since tides are caused by the
  moon and tsunami’ are caused by the
  sudden movements of the ocean. It is
  called tidal because it looks like tide that
  crashes as a large wave. Tsunamis can
  cause major damage and kill people.
       Interest in tsunamis
• Scientists interest: measuring the large
  waves help understand structure and
  nature of the ocean.
• Culture interest: it has an impact on life
  for a long period of time.
• Technology interest: warning sensors
  systems help provide notice to when one
  is coming.
      Indonesian Tsunami 2004
On December 31, 2004 a
tsunami was caused by an
undersea earthquake. This
was the fourth largest
earthquake in the world that
measured a 9 on the Richter
scale. The earthquake was
caused by a tectonic plate
sliding under another. The
wave was 1200-1300 km in
length and 100 km in width.
Picture of Tidal Wave Travel
About me

        My name is Bianca Maddox,
     otherwise known as Tonka. I love the
     roller coasters at Six Flags like
     Batman, Superman and Ninja! I’d
     ride them forever!! And I like the
     1980 Michael Jackson! HEEHEE!

Flick, E. Reinhard. World Book Encyclopedia.

Hill, Alison. www.sfgate.com/getoutside/1996/


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