constructive plate boundaries
volcanoes due to the two plates moving apart leaving a gap. Mid Atlantic ridge, volcanic islands and fold mountains.
how are they formed
inner core heats the magma around it. Magma rises forcing the plates to move. These are called convection currents. Magma from mantle breaks through earths crust. Magma cools on the surface to from lava. Over time this can cause a volcano.
Volcanic islands. lava travels long way before cooling (shield volcano). overtime can create volcanic islands. Then becomes inhabited by life.
two plates moving apart
Destructive plate boundary
volcanoes, mountains, ocean trench and volcanic islands.
earthquakes are formed due to the friction between the two plates creating seismic waves.
ocean trench. These are formed due to one plate being denser than the other (oceanic plate) this folds under the continental plate creating a deep ridge in the ocean. The oceanic plate then melts into magma which then goes into a convection current which forms a volcano.
conservative plate boundary
fault lines and earthquakes
example San Andrea's fault
earthquakes occur because of the friction between the two plates as they try and move past one another at the same time. Normally one of the plates is moving faster than the other. Eventually it will release the pressure that has built up causing an earthquake.
Fault lines are a crack that makes up the boundary between two tectonic plates. There are two types of fault line inactive and active.