Tsunami Hazards


The force of tsunami waves can be extremely dangerous resulting in far more devastation than waves from storm surge. The impact of tsunamis is often severe and largely because of the following characteristcs:

  • Distance. Tsunamis may travel several hundreds of metres inland leading to large scale devastation of property due to inundation. Flooding can extend inland by one km (~0.5 mi) or more, covering large expanses of land with water and debris.
  • Strength. Powerful tsunami waves move dangerous debris such as boats, cars, trees and buildings hundreds of metres inland with great force which can kill or injure people.
  • Speed. Tsunamis travel as fast as a jet plane in open water and although they slow down as they approach land they cannot be outrun.
  • Time. Tsunami waves may come ashore for hours. The first wave is not necessarily the strongest.

2004 Indian Ocean Tsunami, Sumatra

On December 26th, 2004, a magnitude 9.1 earthquake triggered a devastating tsunami which impacted at least 12 countries around the Indian Ocean. Nearly 230,000 people lost their lives, 2.3 million people were left homeless and tens of thousands remain unaccounted for making the 2004 event the deadliest tsunami in recorded history. The event also led to a fervent global effort to strengthen tsunami warning systems and resulted in significant strides in raising public awareness on the impact and safety measures for tsunamis. The images below shows the scale of the devastation.


BEFORE Lhoknga, Sumatra January 2003


AFTER Lhoknga, Sumatra December 2004

Images Courtesy: Ikonos Satellite Image © CRISP, NUS (2003, 2004)

2011 Tōhuku Earthquake & Tsunami, Japan

On March 11th, 2011, a magnitude 9.1 earthquake occurred northeast of Japan triggering a deadly tsunami. The news clip below of this event illustrates the power of tsunamis and clearly shows the difference between tsunamis and normal beach waves. Learn more.