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The Earths Surface
JC: Shaping the crust
| Term | Definition |
|---|---|
| Core | Centre of the Earth. It is the hottest part. |
| Mantle | Lies under the crust. Is made of molten / semi molten rock called magma. |
| Crust | Outer layer of the earth. It is made of solid rock. |
| Plate | The crust is broken into sections called plates. |
| Boundary | The point where each plate meets. |
| Convection Currents | Circular movement of magma formed from the heat of the core. They are found in the mantle and cause the plates to move. |
| Continental Drift | The movement of plates due to convection currents. |
| Destructive Boundary | Plates that collide with each other. These cause fold mountains, volcanic mountains and earthquakes. |
| Constructive Boundary | Plates that separate. These cause volcanic activity that results in volcanic mountains, volcanic islands and mid ocean ridges. |
| Passive Boundary | Plates slide past each other. These cause earthquake activity which results in earthquakes and fault lines. |
| Molten Rock | Melted rock. |
| Magma | Molten / semi molten rock. |
| Pacific Ring of Fire | The edge of the Pacific Plate. A lot of volcanic activity occurs here. |
| Mid Ocean Ridge | Formed when two plates separate. e.g Mid Atlantic Ridge |
| Vent | Narrow tube in the Earths crust. |
| Crater | The top of the volcanic mountain from which lava flows. |
| Magma Chamber | Magma rises up to form a magma chamber in the mantle. |
| Active Volcano | These volcanoes erupt regularly e.g. Mt Etna in Sicily |
| Dormant Volcano | These volcanoes have not erupted for a long time, but may erupt again. e.g. Mt Vesuvius in Italy |
| Extinct Volcano | These volcanoes have not erupted in recorded history e.g Slemish Co Antrim |
| Geyser | A natural hot spring that boils and lets out a large burst of water and steam from time to time. |
| Tremor | Vibration in the earths crust. |
| Faultline | A crack in the ground that occurs when the Earth's tectonic plates move or shift and are areas where earthquakes are likely to occur. |
| Focus | The point beneath the Earths surface where the earthquake happens. |
| Epicentre | The point on the Earth's surface directly above the focus.Tremors are strongest here. |
| Seismograph | An instrument that measures the tremors in the Earths crust. |
| Seismologist | A person who studies earthquakes. |
| Richter Scale | Used to show the strength of an earthquake. The scale ranges from 1 to 12. |
| Tsunami | A huge wave caused when an earthquake occurs under the sea. |
| Fold Mountain | Form when two plates collide with each other. |
| Anticline | An upfold / top of the mountain. |
| Syncline | A downfold / valley. |