Types of volcano

• Conical shape, steep angled size, 1000 feet high.
• Commonly found on the flanks of other volcanoes
  • Neraly 100 cinder cones on the flanks of Mauna Kea, Hawaii
• Initially form around a volcanic vent, made up of alternating layers of ash and cinders (blobs of lava from the volcano rom an eruption)
• During an eruption cinders are erupted and settle around the opening of the vent, then the ash will settle, creating the layers.
  • Direction of the wind can cause an irregular shaped base

Paricutin, Mexico

• Broad, low in height, baal diameter ranges from a few km to over 100 km. The height is usually 1/20th of the width.
• Very runny lava, not very viscous, basaltic lava
  • Usually travels quite far before solidifying
• Often found at divergent plate boundaries

Kilauea, Hawaii

• Nearby residents have been breathing in high levels of sulphur dioxide
• In 1990, an eruption created a lava field that engulfed the town of Kalapana
• There is acid rain from the released sulphur dioxide, damaging crops and buildings.

• Tall cone shaped volcano
• Made up of lava, ash, pumice and tephra (rock fragments and particles)
• Much more explosive than Shield eruptions but less extreme than Calderas
• Magma is andesitic, meaning it contains alot of silica, making it very viscous.
  • This plugs up the crater, making eruptions more explosive.

Mount St.Helens, USA

• May 18th 1980

• Formed when the volcano collapses in on itself
  • This occurs when the volcano erupts, expelling alot of magma, leaving the land above with no support below, leaving it to collapse inwards.
• Can be up to 100km wide
• Formed after a plinian eruption

Krakatoa, Indonesia

• Massive eruption 1883
• Heard 300miles away
• Change dthe global temperature, down by 1.2 degrees C for 5 years
• Destroyed almost the whole island it was on

• Form when andesitic lava solidifies quickly creating a steep sided convex cone
• Formed by repeated violent eruptions of slow moving lava
• High silica content in lava making eruptions violent

Mount Pelee, Martinique

• Erupted massively in 1902
• Killed 30,000
  • Most killed by pyroclastic flow

• Occur at divergent plate boundaries
• Linear vents, usually a few metres wide
• Basaltic magma rises through the cracks, not very viscous
• Eruptions are gentle and persistent

Holuhraun, Iceland

• The eruption is ongoing from 29th August 2014