Term | Definition |
Crust | Is the outer layer of the earth, consists of oceanic and continental crust. |
Core | Is the inner layer of the earth, consists of iron and nickel. |
Mantle | Makes up over 75% of earths volume, consists of several layers of rock(just under the crust). |
Sial | Is the material the continental crust is made out of because it consists silica and aluminium. |
Sima | Is the material the oceanic crust is made out of because it consist of silica and magnesium. |
Lithosphere | Is the name given to the crust and the upper part of the mantle. |
Asthenosphere | is the region just below the lithosphere. |
Plates | Are the large ridged sections that the lithosphere is divided up into. |
Continental fit | Is the coasts of the continents surrounding the Atlantic ocean could fit together like a jigsaw puzzle, if the continents were moved closer. |
Convection Currents | Are in the mantle and are the main cause of plate movement. |
Divergent Boundary | Is when plates separate and move apart from one another since new rock is formed, these are constructive boundaries. |
Convergent boundary | Is when plates collide with one another since rock is destroyed, these are destructive boundaries. |
Transform Boundary | Is when plates grind past one another since rock is neither formed or destroyed, these are passive boundaries. |
Subduction | When one plate sinks below the other. |
Fault line | Is the line along which the plates slide |
Active volcano | Are volcanoes that are currently erupting or showing signs of unrest E.g. Mount Ethna. |
Dormant volcano | Are volcanoes that haven't erupted in at least 600 years and are now quiet but have a high probability that they'll erupt again E.g. Mount St Helens. |
Extinct volcano | Are volcanoes that haven't erupted in historical time E.g. Slemish Mountain in Antrim |
vent | The passage that goes up through a volcanic cone to allow lava to erupt on the surface. |
Crater | Is a steep-sided depression found at the top of the volcano. |
Pyroclastic cloud | Is a cloud consisting of volcanic ash. |
Basic lava | Is the lava that has less silica, causes it to be runny. |
Acidic lava | Is the lava that has more silica, causes it to be not as runny. |
Lahar | Is when ash and dust gets mixed up with rain or melted snow, a wet debris flow, a lahar can flow down slopes at speeds up to 200kmph |
Intrusive | Is when the magma cools deep underground and forms intrusive landforms. |
Extrustive | Is when the magma makes its way to the surface of the earth and cools. |
Hot spot | Hot mantle under the plate known as a hot spot. |
Fissure | Large fractures in the earths crust. |
Laccoliths | Are dome-like structures with a flat floor. |
Sills | Are horizontal sheets of volcanic rock that run parallel to the rock strata. |
Dyke | Are thin vertical sheets of volcanic rock that run perpendicular to the rock strata. |
Batholith | large platons at the surface and are greater then 100km. |