Earthquakes and Tsunamis Quiz

Understanding Earthquakes and Tsunamis

• Tsunamis are not tidal waves, they are large water waves caused by underwater earthquakes, reaching up to 100 feet in height, and causing destruction on land.
• Earthquakes can occur on intraplate faults, not just on tectonic plate boundaries, such as the New Madrid Fault in the United States.
• An earthquake consists of three main parts: the focus, seismic waves, and the fault along which the earthquake occurs.
• The focus is the origin of the earthquake, seismic waves are mechanical energy propagation through the earth's layers, and the fault line is where the mechanical energy is released.
• The epicenter is the surface location directly above the focus of the earthquake, and the hypocenter is another term for the focus.
• There are four types of seismic waves: primary (P-) waves, secondary (S-) waves, Rayleigh waves, and Love waves, each with distinct properties and behaviors.
• Faults are cracks in the earth where two sections of rock can move relative to each other, and there are three main types: thrust or reverse faults, normal faults, and strike-slip faults, each with different motion.
• The majority of earthquakes occur along tectonic boundaries and faults in the earth's crust, with tectonic earthquakes caused by tectonic plates moving against each other along a fault.
• Tectonic earthquakes occur in five stages: elastic build-up, dilatancy, influx of water, earthquake, and aftershocks, as identified by geologist Henry Fielding Reid.
• There are four types of earthquakes: tectonic, volcanic, collapse, and explosion, each triggered by different events.
• Tectonic earthquakes are caused by sliding along a fault or tectonic boundary, volcanic earthquakes are triggered by nearby volcanic activity, collapse earthquakes occur in underground caves or mines, and explosion earthquakes are caused by detonation of a nuclear or chemical bomb.