Tsunamis – Waves That Cross Oceans

An ordinary wave rolls onto the sand every few seconds; a tsunami can take tens of minutes between crests and cross an entire ocean at the speed of a jet aircraft while barely rippling the surface. This episode explains how a shifting sea floor generates a tsunami, why shallow-water wave physics makes them slow and pile up catastrophically near shore, and treats the 2004 Indian Ocean and 2011 Tohoku events with the care and accuracy they deserve, alongside how modern warning systems, including Australia's, actually work.

You'll come away understanding how undersea earthquakes and landslides displace the entire water column to generate a tsunami, why that makes tsunamis behave completely differently from wind-driven waves, what drawback is and why it's a critical warning sign, what happened in 2004 and 2011 and what those events taught scientists, how the Joint Australian Tsunami Warning Centre and international systems detect and warn of tsunamis today, and why real limits remain on how precisely a tsunami's impact can be predicted in the crucial first minutes after an earthquake.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Geoscience Australia – Joint Australian Tsunami Warning Centre resources; Bureau of Meteorology – tsunami warning services; NOAA National Weather Service – tsunami science and warning explainers; UNESCO Intergovernmental Oceanographic Commission – Indian Ocean Tsunami Warning System background.