Earth Structure
Crust
Outermost solid layer of the Earth
Oceanic Crust
Thin dense crust made of Basalt rock
Ngauruhoe
Stratovolcano found in the central North Island made of Andesite magma and ash
Lava
Molten rock that has reached the surface of the crust
Magma
Molten rock that has not reached the surface of the crust
Basalt Magma
Runny magma low in silica, forms when the mantle melts at divergent plate boundaries
Outer Core
Liquid metal that moves and generates Earth's magnetic field
Continental Crust
Thick less dense crust made of Granite
Taupō
Large Caldera volcano formed from Rhyolite magma
Pyroclastic Flow
Hot ash and volcanic gasses that move extremely quickly down the side of the volcano, formed when an ash cloud collapses
Lahar
Avalanche of ash and water that can flow down the side of volcanic cones
Andesite Magma
More viscous magma, forms when molten mantle mixes with continental crust and picks up more silica, has higher silica content than Basalt
S-Waves
Seismic waves that can move through solids but not liquids
Divergent Boundary
When two plates move apart from each other creating a rift
Alpine Fault
Runs down the West coast of the South Island, Australian and Pacific plates slide past one another in a transform plate boundary
Shield Volcano
Low, wide volcano made of basalt magma flows, formed at divergent plate boundaries
Tephra
Anything that gets thrown up into the air during a volcanic eruption eg. ash, lava bombs, pieces of pumice, etc.
Rhyolite Magma
Thick viscous magma forms when Basalt magma ponds under continental crust and melts the crust itself, high in silica content
Lithosphere
Upper mantle and the crust, solid and rigid, moves on top of convection currents
Convergent Boundary
When two plates move towards each other and collide
Kermadec Trench
Subduction zone that stretches from North-East of the North Island down through Taupō, Pacific plate sinks underneath the Australian plate
Stratovolcano
Tall narrow cone made of alternating layers of ash and Andesite magma flows, forms at subduction zones
Ash Cloud
Magma that gets ripped apart by gas bubbles forms a large cloud of small particles in the air called ash
Convection Current
Circular flow of mantle in the asthenosphere, transfers heat to the upper mantle and can cause parts of the mantle to melt into magma
Asthenosphere
Semi solid part of the mantle that flows due to convection currents
Subduction
When oceanic crust collides with continental crust, the more dense oceanic crust sinks down into the mantle
Puysegur Subduction Zone
South-West of the South Island where the Australian plate subducts under the Pacific plate
Caldera
Collapsed dome volcano formed from Rhyolite magma that erupts explosively
Dome Volcano
Water, Less Pressure, Increased Temperature
Processes that cause the mantle to melt into liquid magma - water breaks bonds between molecules, pressure allows particles to move apart, temperature also causes particles to move apart