Shield & Composite Volcanoes p.2

Question 1

Volcanoes; Middle Of Ocean / Hotspots

Answer 1

Hotspots occur when magma plume (unusually hot parts of the mantle) break through the crust creating a volcano. Hotspots are static, so as the tectonic plate moves, a second volcano forms next to the first one. The hotspot continues staying still and the plate continues moving along, eventually a third volcano will form. Overtime, (thousands/millions of years) a chain of volcanoes is formed, just like in Hawaii

Question 2

Characteristics of Composite Volcanoes

Answer 2

• Pyroclastic flow, mixture of hot steam, ash rock and dust, temp over 400°, high speeds
• Usually found at destructive plate boundaries
• Made of alternating layers of lava and ash (other volcanoes only consist of ash)
• Formed by eruptions of thick, viscous lava

Question 3

Characteristics of Shield Volcanoes

Answer 3

• Usually found at constructive plate boundaries
• Low, gently sloping sides
• Formed by eruptions of thin, runny lava
• Eruptions are frequent but relatively gentle