Tectonic hazards

• Earthquakes occur along plate boundaries where there is movement between the plates.
• Converging tectonic plates can cause one to dive beneath another, resulting in an earthquake.
• The Richter scale measures the magnitude or size of an earthquake based on its energy release.
• Magnitude 5-6 earthquakes have moderate effects and can damage poorly constructed buildings.
• Tsunami waves are generated by sudden displacement of water caused by underwater landslides, volcanic eruptions, or earthquakes.
• Volcanoes are formed when magma rises from deep within the Earth's mantle through cracks in the overlying rock layers.
• There are three types of volcanoes: shield volcanoes (low viscosity lava), composite/stratovolcanoes (high viscosity lava), and cinder cone volcanoes (small explosive eruption).
• Pyroclastic flows are fast moving currents of hot ash and gas that travel down the side of a volcano at high speeds.
• Lahars are mudflows triggered by heavy rainfall on active volcanoes.
• The Ring of Fire is an area around the Pacific Ocean where many tectonic plates meet, resulting in frequent seismic activity including earthquakes and volcanic eruptions.
• Fault lines are fractures in rocks along which movement occurs during earthquakes.
• slab pull occurs at destructive plate margins where denser oceanic crust subducts under continent crust due to gravity, pulling the rest of the plate with it
• ridge push occurs at constructive plate margins where newly formed dense oceanic crust slides down away from the plate margin pushing the plates apart