Volcanoes these notes go on p 11 of your inb
Sponsored Links
This presentation is the property of its rightful owner.
1 / 28

Volcanoes These notes go on p. 11 of your inb !!! PowerPoint PPT Presentation


  • 45 Views
  • Uploaded on
  • Presentation posted in: General

Volcanoes These notes go on p. 11 of your inb !!!. Volcanic Settings (Plate Boundaries). Ocean-Continent Convergence. Ocean-Ocean Convergence. CONTINENTAL divergence. Ocean Divergence. Major Volcanoes Around the World.

Download Presentation

Volcanoes These notes go on p. 11 of your inb !!!

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


VolcanoesThese notes go on p. 11 of your inb!!!


Volcanic Settings (Plate Boundaries)

Ocean-Continent Convergence

Ocean-Ocean Convergence

CONTINENTAL divergence

Ocean Divergence


Major Volcanoes Around the World


“RING OF FIRE”:Area surrounding the pacific plate where the most volcanoes & earthquakes occur


Plate Tectonics and Magma Generation


Viscosity

Chemistry of Magma

Gases within the magma

Water content of magma

PARAMETERS OF VOLCANISM


  • Active Volcanoes: recent eruptions, active magma source

    • Mt. Etna, Italy

  • Dormant Volcanoes: no recent eruptions, but still has an active source of magma

    • Mt. St. Helens, USA

  • Extinct Volcanoes: no recent eruptions, no source of magma

    • Northwestern Hawaiian Islands

Volcanic activity


  • Viscosity- the resistance of lava to flow

    • Ex: The more viscous the lava, the thicker and stickier the material & the harder it is to flow (honey vs. water)

TERMS TO KNOW:

  • depends on the amount of silica

  • the type of crust being melted determines the amount of silica!


Caldera: large crater shaped basin that forms when the top of a volcano collapses

Terms to know:


Formation of Crater Lake


Kaui

Oahu

Molokai

Lanai

Maui

Hawaii

Terms to know:

  • Hot Spot- random upwelling of magma NOT associated with convection in the mantle

    • create a special type of volcanism not associated with plate boundaries

    • Ex: Hawaii, Yellowstone & Iceland


Tectonic Settings and Volcanic Activity


Cinder Cone

1. Cinder Cones: explosive eruptions, small but steep slopes, pyroclastics

3 types of volcanic cones:


Volcano Types


2. Shield: non-explosive eruptions, fluid basaltic lava, gentle broad slopes

3 types of volcanic cones:


Volcano Types


3. Composite Cones/Stratovolcanoes: alternating between lava and pyroclastics, explosive and non-explosive eruptions, very steep/tall

3 types of volcanic cones:


Volcano Types


Volcanism at different plate boundaries


  • Effusive Eruption (non-violent): low viscosity, flows easily, gases escape easily

  • Magma Type: mafic (dark, dense seafloor)

  • Volcano Type: Shield Volcanoes

  • Lava Type: Pillow

    http://www.youtube.com/watch?v=DdIUuUY0L9c

C

Mid-ocean ridges & oceanic hot spots


  • Pillow Basalts (underwater)

    http://www.youtube.com/watch?v=DdIUuUY0L9c

  • AA lava- jagged lava

  • Pahoehoe- ropey, smooth lava

C

Basaltic Lava Types


Mostly Explosive Eruption (violent):high viscosity, does not flow easily, gases trapped, hard to predict explosions

Magma Type: felsic & mafic

Volcano Type: Composite Cone (Stratovolcanoes) & cinder cones

Other Features: gas flows, calderas, aerial bombs

C

Subduction boundaries


searing superheated gas and volcanic ash & dust; very fast

Also called

“NueeArdente”

C

PYROCLASTIC FLOWS

http://www.youtube.com/watch?v=-H_HZVY1tT4

Mt. St. Helens Eruption

http://www.youtube.com/watch?v=WxlRpuTed6g

Pyroclastic Flow


Debris Avalanche and Eruption of Mount St. Helens, Washington


C

Continental divergent boundary & Continental hot spots

  • Explosive Eruption (violent):high viscosity, does not flow easily, gases trapped, hard to predict explosions (always explosive!)

  • Magma Type: felsic or rhyolitic

  • Volcano Type: Composite Cone (Stratovolcanoes),cinder cones, dome complexes

  • Other Features: gas flows, calderas, aerial bombs, pyroclastic flows


Basaltic Magma

Rhyolitic Magma

Andesitic Magma

Silica Content

Least (~50%)

Intermediate (~60%)

Most (~70%)

Gas Content

Least

Intermediate

Most

Viscosity

Least viscous

Intermediate

Most viscous

Type of Eruption

Rarely explosive

Usually explosive

Sometimes explosive

Melting Temp.

Highest

Intermediate

Lowest

Location

Subduction boundaries

Rifts, oceanic hot spots

Continental hot spots

Magma and Erupted Materials


  • Draw an exaggerated, cartoon form of a type of volcano

    • Cinder

    • Shield (Dome)

    • Composite

  • Write a 5-6 sentence summary

    about it’s “personality.”

    Must include type of eruption, type of lava, size/shape, and location.

Volcano CarIcAtures


  • Login