PowerPoint Presentation - Volcanoes of Hawaii

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Volcanoes of the Island of Hawaii
GG103 Nasir Gadzar
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(No Transcript)
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http//pubs.usgs.gov/gip/hazards/mauna-loa.html
http//pubs.usgs.gov/gip/hazards/maunakea
-kohala.html http//pubs.usgs.gov/gip/ha
zards/hualalai.html http//pubs.usgs.gov
/gip/hazards/kilauea.html
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Mahukona
Loihihi
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Objectives

• Volcanoes Defined
• Types of Volcanoes
• Volcanoes of the island of Hawaii
• Descriptions
• Images
• Presentation Summary

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Volcanoes Defined

• volcano   n.   pl., volcanoes or volcanos.
  Abbr. vol.
• 1. a. An opening in the earth's crust through
  which molten lava, ash, and gases are ejected. b.
  A similar opening on the surface of another
  planet.
• 2. A mountain formed by the materials ejected
  from a volcano.

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Types of Volcanoes

• Geologist categorize volcanoes into four groups.
• 1)Composite
• 2)Cinder
• 3)Shield
• 4)Lava domes

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Composite Volcanoes

• Called composite because they are made of
  alternating layers of lava and rock.
• Oftentimes called Stratovolcanoes
• Physical Characteristics
• Steep
• Symmetrical cone shaped
• Often have snowcapped tops
• Explosive eruptions

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Examples of Composite volcanoes
Mount Ranier, Washington, USA
Mount Fuji, Honshu, Japan
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Cinder Volcanoes

• Simplest type of volcano
• Built from particles globs of coagulated lava
  expelled from a solitary vent which then falls
  and solidifies around the vent to form a circular
  cone.
• Physical Characteristics
• Bowl shaped crater
• Size is usually about 1000ft. The size of a hill.
• Single vent

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Example of Cinder cone volcanoe
 Parícutin volocano, Mexico
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Lava domes

• Also known as volcanic domes
• Usually occur on flanks of composite volcanoes
• Formed by bulbous masses of lava too viscous to
  flow any great distance, eventually piles around
  vent and dome becomes bigger from acitivity
  within.
• Physical Characteristics
• Rounded
• Steep sided

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Example of Lava dome
Unzen lava dome, Japan
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Shield Volcano

• Built almost entirely of fluid lava flows. Flow
  pours out in all directions from a central summit
  vent, or group of vents, building a broad, gently
  sloping cone of flat, domical shape, that
  profiles a warrior shield.
• built up slowly by the accretion of thousands of
  highly fluid lava flows called basalt lava that
  spread widely over great distances, and then cool
  as thin, gently dipping sheets. Lavas also
  commonly erupt from vents along fractures (rift
  zones) that develop on the flanks of the cone.

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Shield Volcano facts

• 3-4 miles in diameter but heights of 1500-2000
  feet.
• The Hawaiian Islands are composed of linear
  chains of these volcanoes.
• Shield Volcanoes of the Island of Hawaii
• Kilauea
• Mauna Loa
• Mauna Kea
• Hualalai
• Kohala

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Kilauea

• Southernmost shield volcano on the Big Island.
• Predominantly erupts basaltic lava in profuse
  eruptions.
• Kilauea stands just under 4200 feet tall at it's
  highest point.
• Kilauea has a 165m deep circular caldera at its
  summit that measures 3x5km.

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Kilauea
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Mauna Loa

• At 60 miles long and 30 miles wide, it makes up
  half of the entire island.
• Mauna Loa is the largest active volcano in the
  world.
• The thickness of its lava pile from the center of
  the volcano from is 56,080 ft (17,170 m).

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Mauna Loa
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Maunakea

• Tallest volcano on the Island of Hawaii.
• Tallest mountain in the world.
• From sea floor to summit it towers more than 5.6
  miles (9 km).
• Mauna Kea is the only Hawaiian volcano known to
  be glaciated.
• The most recent eruption was about 3,500 years
  ago. Mauna Kea is considered a dormant volcano.

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Mauna Kea
Cinder cone on top of Mauna Kea
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Hualailai

• The summit of Hualalai rises to an elevation of
  2523m (8271ft) above sea level.
• Hualalai is well-known in Hawaii as a good source
  for mantle xenoliths.
• The surface of Hualalai is entirely composed of
  post-shield alkalic basalts.
• The last historical eruption at Hualalai ended in
  1801. This eruption produced very fluid, high
  velocity lava flows that entered the ocean off
  western Hawaii.
• Presently, the volcano is mantled by alkalic
  lavas erupted during the post-shield stage of
  volcanism.

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Hualalai
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Kohala

• Summit elevation of 1700 m (5577ft.)
• Kohala is considered to be extinct because it has
  not erupted for 60,000 years.
• Kohala is the oldest of the sub-aerial volcanoes
  that make the Island Of Hawaii.

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Kohala
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Presentation Summary

• Volcanoes are openings in the earth's crust
  through which molten lava, ash, and gases are
  ejected.
• There are four categories of volcanoes
• 1) Composite
• 2) Cinder
• 3) Lava dome
• 4) Shield
• Volcanoes found in the island of Hawaii are
  Shield volcanoes, these volcanoes names are
  Kilauea, Mauna Loa, Mauna Kea, Hualalai, and
  Kohala. Mahukona is a seamount in west.