Volcanoes Flashcards
Where do we find volcanoes?
-destructive subduction boundaries
-constructive plate margins
-hot spots
Why do you find volcanoes at destructive subduction boundaries?
-release of pressure due to crust going into mantle so magma has to come out as it is a finite system
Why do you find volcanos at constructive plate margins?
- as plates pull apart the magma rises up to fill the gap
Why do you find volcanoes at hot spots?
localised areas of intense heat caused magma plumes
What is a Magma Plume?
- a magma plume is a localised thermal current heated from the lower mantle which results in a vertical rise of magma- the rising part of a convection current.
Where are Magma plumes found?
- usually close to a plate margin
-sometimes within the centre of plate
Hawaiian eruption
-type of magma
-characteristic of eruption
-basaltic lava
-lava flows gently from a central vent
Icelandic eruption
-type of magma
-characteristic of eruption
- basaltic lava
-lava flows gently from fissures
Strombolian eruption
-type of magma
-characteristic of eruption
-thicker basaltic lava
-frequent , explosive eruptions of tephra and steam
-occasional short lava flows
Vulcanian eruption
-type of magma
-characteristic of eruption
-thicker basaltic, andestic and rhyolitic lava
-less frequent but more violent eruptions of gases, ash and tephra (including lapili )
Vesuvian eruption
-type of magma
-characteristic of eruption
-Thicker basaltic , andesitic and rhyolitic
-following long periods of inactivity, very violent gas explosions blast ash high into the sky
Pilian Eruption
-type of magma
-characteristic of eruption
-rhyolitic lava
-exceptionally violent eruptions of gases ash and pumice torrential rainstorms causing devastating lahars
Peleean eruption
-type of magma
-characteristic of eruption
-andestic and rhyolitic lava
-very violent eruptions of nuees and ardenes.
