Volcano Research Paper

1. Volcano Research Paper • Intro: define volcano & define tectonic plate boundaries. • *many volcanoes form on plate boundaries • *a few processes cause rock to melt, forming magma • *because magma is not as dense as the rock around it, it moves up & erupts to form a volcano • What is a volcano? A crack in the Earth’s surface where melted rock (lava/magma) and gases pass.

2. Where Volcanoes Form Divergent Boundary • Boundary between two tectonic plates that are pulling away from each-other. • Molten rock also forms submarine volcanoes • The denser plates forms to make a trench • Fissures form • Mid-ocean ridges are formed • Molten rock flows through the fissures onto the ocean floor. • Divergent boundaries under water chains known as mid-ocean ridges.

3. Where Volcanoes Form Cont. Convergent Boundary • A boundary when plates collide and it gets denser and bends • One plate moves under the other (this is called subduction) • As a plate moves down it gets greater heat & pressure • Plates release fluid which causes surrounding rock to melt • When subduction occurs, the denser plate moves underneath the lighter plate---creating a trench • As the plates subduct, the rock receives greater pressure / this pressure causes the plate to give off fluid.

4. Where Volcanoes Form Cont. Hot Spots • Places that experience a great deal of volcanic activity, but do not lie on plate boundaries • Sit over columns of hot rock that come up that come up through the Earth’s mantle • The columns do not move and are called mantle plumes • The plate slips over this column of hot rock, and as the magma comes up, it creates a chain of volcanic islands. The Hawaiian Islands are an example of this

5. How Magma Forms • Magma is made deep in the Earth’s crust and in the upper sections of the mantle • Temperature is high and there is a great deal of pressure • When temperature /pressure change, magma forms. Specifically temp. up and pressure down---makes rock melt • Water can also make the melting temp. of rock lover, causing it to melt • Temperature causes some minerals to melt and form magma • When pressure on rock goes down, it creates space around rock. The rock then expands & melts, creating magma adding fluids • In the lithosphere of oceanic plates, there is sediment and volcanic rock that holds water and other fluids • When an oceanic plate subducts, the fluids come into contact with the surrounding rock • When fluids enter, the melting temp. decreases and rock begins to melt.