http volcano und nodak edu volcanoes html BIG BOOMS Volcanoes and Earthquakes Earth2Class Workshops for Teachers Lamont Doherty Earth Observatory Originally presente by tiw14488

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        BIG BOOMS!
  Volcanoes and Earthquakes
 Earth2Class Workshops for Teachers
  Lamont-Doherty Earth Observatory
Originally presented 20 November 2004
Guest Scientists:

         Art Lerner-Lam

         Steve Goldstein
• The main focus of today’s workshop will be
• Recent activity at Mt. St. Helens in southern
  Washington has raised interest in volcanic
  activity within the continental United States
• The LDEO campus lies atop the Palisades
  Sill, remnant of igneous activity 195 MYA +/-
    Volcanic Activity by Land and Sea
• We tend to be aware of the continental
  volcanoes, but of course most crustal lava
  forms the ocean floors
• The Mid-Ocean Ridge is basaltic flows, with
  islands rising above the sea surface in
  various locations
• Scattered through the ocean basins,
  especially in the Pacific, are hundreds of
  seamounts and guyots
    Mapping the Sea Floors in Detail
                                          • Modern technologies,
                                            such as side-scan
                                            sonars, create maps of
                                            the ocean floors in
                                            much greater detail
                                            than previously
                                          • Here is a section of the
                                            East Pacific Rise and
                                            nearby seamounts.
       A Major Surprise in the Deep!
The most spectacular
  discovery about mid-
  ocean ridge lava
  flows was made in
  1977 when “black
  smokers” – hydro-
  thermal vents rich in
  sulphide minerals –
  were first observed
  by the “Alvin.”
The Hawaiian Islands
are some of the largest
volcanoes on Earth.
This image showing
Mauna Kea (MK), Mauna
Loa (ML), Hualalai (H),
and Kohala (K) was taken
from near the summit of East Maui volcano. These
are SHIELD VOLCANOES, which form from a fluid
Lava that solidifies to form basalt.
   For more about shield volcanoes, go to:
This is Arenal in Costa                   More than 60% of all
  Rica, a volcano                          volcanoes are
  almost always in                         STRATOVOLCANOES.
  eruption.                                These consist of
                                           andesite or other lavas
                                           that are cooler and more
                                           viscous than basalt
                                           lavas, interlayered with
                                           pyroclastic materials.
               CINDER CONES
 A third type of
volcano involves
cones built mainly of
cinders and ash. One
of the most famous is
Paricutin, Mexico,
which was observed
from its beginning in
                        Flood Basalts
                                        • At times in the Earth’s
                                          history, vast amounts
                                          of lava have spewed
                                          out onto the surface,
                                          covering thousands of
                                          sq. km. with “flood
                                        • The Columbia Flood
                                          Basalt in the Pacific
                                          NW is the US’ largest
        Where do volcanoes exist?
              On every continent!
Here is a link where you can find images of
 volcanoes from almost every continent:

Much of Antarctica is volcanic, including Mt.
 Erebus, the southernmost volcano
 Volcanoes at the Top of the World
   Young volcanoes have been identified in
  the East Gakkel Ridge of the Arctic Ocean
  by bathymetric surveys conducted from a
  submarine in 1999.
   The Arctic Mod-Ocean Ridge Expedition
  (AMORE) in 2001 explored more than a
  thousand km of this feature.
Where Are Volcanoes Erupting Now?

One of the best sources for information for
 current volcanic activity is maintained by
 the USGS/Smithsonian Institution’s
 Global Volcanism Program
        What’s the Link between Volcanoes
                and Earthquakes?
   • Comparison of the distribution patterns of
     volcanoes and earthquakes show much
     overlap, as the next slide shows.
   • Both occur primarily at plate boundaries.
   • A few volcanoes occur
     at “Hot Spots” or mark
     where such features
     once were located.
       Examples of Pertinent Core
          Concepts (PS/ES)
• 2.1a. Earth systems have internal and external sources
  of energy, both of which create heat.
• 2.1b. The transfer of heat energy within Earth's interior
  results in the formation of regions of different densities.
  These density differences result in motion.
• 2.1n. Many of Earth's surface features are the
  consequence of forces associated with plate motion and
  interaction. These include: mid-ocean ridges/rifts;
  subduction zones trenches/island arcs; mountain ranges
  (folded, faulted, and volcanic); hot spots; and the
  magnetic and age patterns in surface bedrock.
• 2.1l. The lithosphere consists of separate plates that ride on the
  more fluid asthenosphere and move slowly in relationship to one
  another, creating convergent, divergent, and transform plate
  boundaries. These motions indicate Earth is a dynamic geologic
  > These plate boundaries are the sites of most earthquakes,
  volcanoes, and young mountain ranges.
  > Compared to continental crust, ocean crust is thinner and denser.
  New ocean crust continues to form at mid-ocean ridges.
  > Earthquakes and volcanoes present geologic hazards to humans.
  Loss of property, personal injury, and loss of life can be reduced by
  effective emergency procedures.
    Teaching about Volcanoes
• Volcano World
    The best web site for teaching and
 learning about volcanoes was created by
 the University of North Dakota.

     The USGS also provides great
 information, images, and lessons.
Volcanoes are Well-Suited to Hands-on
Here are links to some examples:

• Scott Johnson (Grand Forks, ND) has created
  many fine lessons for Volcano World. Two
  examples are “Erupting Volcano” and “Lava
  Dome Building”
• USGS/Cascades Volcano Observatory has
  developed some nice lessons, including a variety
  of paper models
Following a break, we will learn more
about the science and skill of investigating
volcanoes from Art Lerner-Lam and Steve

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