Glossary of Terms

Term	Explanation
Amplitude	The difference between the peak or trough of a tsunami and the undisturbed sea level at the time.
Drawdown	The lowering level of the ocean from the shoreline.
Generation	Formation/creation of tsunami.
Inundation	Water that overflows onto normally dry land; the horizontal distance inland that a tsunami reaches.
Pyroclastic	Combination of hot blocks, pumice, ash and gas.
Propagation	Tsunami spreading outwards from a generation site.
Run-up	The maximum vertical height of the sea surface reached during a tsunami.
Seismic	Movements of the earth's crust that are usually caused by earthquakes, explosions or volcanic eruptions.
Shoaling	An increase in tsunami height as it reaches shallow water.
Subduction	The action of one tectonic plate moving under another.
Subduction zone	A region where the movement of one tectonic plate under another plate occurs.
Tectonic plates	Rigid plates that make up the Earth's surface that are either converging, diverging or slipping past one another.
Tsunamigenic	Having generated a tsunami.
Water column	Area of water from the sea surface to the sea floor.
Wave crest	The highest part of the wave.
Wave trough	The lowest part of the wave.
Wavelength	The distance between the peak of one wave and the peak of the next wave.

Sources: Geoscience Australia, the Bureau of Meteorology, Attorney-General's Department, International Tsunami Information Centre, Pacific Tsunami Museum, National Oceanic and Atmospheric Association (US), US Geological Survey, Merriam-Webster Dictionary Online.