Volcanoe's

?
  • Created by: zahra
  • Created on: 08-05-10 13:01

VOLCANOE'S

Types of volcanoe's

Sheild volcanoe's

- found on constructive plate margins and above HOTSPOTS

  • Basic lava (above 1200 c) lava is very RUNNY and flows LONG DISTANCES before COOLING and SOLIDIFYING
  • Many gentle Eruptions form a very large CONESHAPED MOUNTAIN with GENTLE SLOPING SIDE'S often UNDERSEA
  • Example : Mauna Loa, Hawaii, USA

Composite volcanoe's

- found on DESTRCUTIVE PLATE MARGINS

  • ACID LAVA (800c) is THICK and STICKY
  • Alternate Explosion ERUPTIONS OF ASH followed by GENTLE ERUPTS of Lava build a CONE SHAPED MOUNTAIN with STEEP SIDES
  • Exampe : Mt St helens, Washington, USA

Supervolcanoe's

- are reatively rare, but found on destructive plate margins & above hotspots. Most recent was 74,000 years ago in Toba, Indonesia

  • MASSIVE EXPLOSION eruptions of ash forming a SUNKEN CRATER called a CALDERA. can be over 40 miles wide
  • ASH would fall across the WHOLE WORLD killing PEOPLE, WILDLIFE & VEGETATION. Ash in atmosphere would trigger GLOBAL

Comments

No comments have yet been made