Science Volcanoes

What is molten rock beneath the earths surface?

Magma

What are the three factors that effect the formation of magma

Heat, Pressure, Water content

What are the two sources of heat for melting rock

friciton from two slabs rubbing together and heat from the lower mantle rising

Does pressure raise or lower the melting point

raise

What is melting due to derease in pressure

decompression melting

does water contained in a rock raise or lower melting point

lower

How does water get deep within the mantle

subduction on ocean plates

What are the three locations where we could expect to see volcanic formation

Diverget, convergent boundaries and hot spots

What is an example of volcanism at a divergent boundary?

Mid ocean ridge

An example of volcanoes at a convergent plate boundary

volcanic arcs, continental and island

What is the ring of fire

large number of volcanoes around pacific ocean plate created by subducting lithosphere

How were the hawaiian islands created

they are on hotspot which gives them the lava upwards and the plate moves making multiple islands

At a convergent plate boundary, the fluids reduce the melting point of hot mantle rock enough for melting to begin when sinking slab reacher a depth of about

100-150km

What are two factors that affect the type of explosion from a volcano

viscoity and disolved gasses

Magma with what kind of viscosity causes a larger eruption

high

Heat increases, viscosity

decreases

What type of lava tends to not be explosive

basaltic

What type of lava traps more gas bubbles

high viscosity

What are solid matrerials produced from volcanic eruptions? what is a flow of liquid rock?

lava flows, eject pyroclastic materials, or both

What affects characteristics of lava viscosity

chemical composition and temerature

What is the location where lava is released

vent

what type of volcano is broad and slightly domed

shield

what type of volcano typically results in one time eruptions

cinder cone

what type of volcano is composed of lava flow and pyroclastic materials

composite

What is a crater left behind from a volcano that ocllapsed into its empty magma chamber?

caldera

What is the landform made from the remains of magma hardened in the volcanos pipe

volcanic neck

What is made of layes of think runny lava eruption from a long narrow crack

lava platau

Igneous rock that covers much of the planets surface is formed from cooled what?

Magma

What is the term for rock formed from magma cooling underground

intrusive igneous

What are structures that are formed from the hardening of magma beneath the earths surface

plutons

How are plutons classified

shape, size, and relationship to surrounding rock layers

What is magma that intrudes between two rock layers?

sill

What is a lens shaped pluton that pusjed overlying rock layers upwards

lacoliths

What is a pluton that forms and cuts across layers of rocks

dike

What is igneous rock that has surface exposure of more that 100 km²

Batholith