Tsunami

In this explainer series, 9news.com.au is examining the concerns and fears around natural disasters, examining potential impacts on Australia.

"As that disturbance propagates upwards it gets to be quite large and affects the ionosphere, and that affects the signals of the GPS satellites. "Sydney is more vulnerable, simply because there's more people, a lot close to the beach, and the density of construction." "These days we would be well aware it's on its way, and a pretty good idea of even the height. "The main sources are south of New Zealand, because normally it's a subduction zone that causes the very large thrust earthquakes, which causes very large tsunamis. "That could potentially be affected if there was a large earthquake south of New Zealand, which could also affect the eastern coast of Tasmania. The wave destroyed "several campsites" and there was evidence of inundation up to 200 metres inland. "They had the anchor out, and he couldn't pull it in in time," Cummins said. "As the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases," it explains. "That was the largest run-up ever measured in Australia," Cummins explained. "The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave." "If you threw a stone into a pond there would be a single disturbance, but there would be many ripples that go through the pond. The National Oceanic and Atmospheric Administration (NOAA) defines a tsunami as "a series of waves caused by earthquakes or undersea volcanic eruptions."