Portal:Tsunamis

The Tsunami portal

The 2004 Indian Ocean tsunami at Ao Nang, Krabi Province, Thailand

A tsunami (/(t)suːˈnɑːmi, (t)sʊˈ-/ (t)soo-NAH-mee, (t)suu-; from Japanese: 津波, lit. 'harbour wave', pronounced [tsɯnami]) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances) above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event.

Selected article

A tsunami warning system (TWS) is used to detect tsunamis in advance and issue the warnings to prevent loss of life and damage to property. It is made up of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of the coastal areas. There are two distinct types of tsunami warning systems: international and regional. When operating, seismic alerts are used to instigate the watches and warnings; then, data from observed sea level height (either shore-based tide gauges or DART buoys) are used to verify the existence of a tsunami. Other systems have been proposed to augment the warning procedures; for example, it has been suggested that the duration and frequency content of t-wave energy (which is earthquake energy trapped in the ocean SOFAR channel) is indicative of an earthquake's tsunami potential. (Full article...)

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Events that can cause a tsunami

An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. (Full article...)

List of events articles
Submarine earthquake Tsunami earthquake Submarine eruption Landslide Glacier calving Meteorite impact

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General images

The following are images from various tsunami-related articles on Wikipedia.

Image 1The energy released produces tsunami waves. (from Tsunami)
Image 2Evacuation route sign on the pavement in Kamakura, Japan (from Tsunami warning system)
Image 3A seawall at Tsu, Mie Prefecture in Japan
Image 4An illustration of the rhythmic "drawback" of surface water associated with a wave. It follows that a very large drawback may herald the arrival of a very large wave. (from Tsunami)
Image 5The 2004 Indian Ocean tsunami at Ao Nang, Krabi Province, Thailand (from Tsunami)
Image 6Japanese Tsunami warning sign (from Tsunami warning system)
Image 7Satellite image of Lake Kivu (from Tsunamis in lakes)
Image 8Mast with warning system, and sign detailing escape routes, on the coast of Okumatsushima, Miyagi prefecture, Japan (this coast was severely hit by the 2011 tsunami) (from Tsunami warning system)
Image 9Evacuation route sign in a low-lying coastal area on the West Coast of the United States (from Tsunami warning system)
Image 10Tsunami aftermath in Aceh, Indonesia, December 2004 (from Tsunami)
Image 11Figure 1: Diagram showing how earthquakes can generate a tsunami. (from Tsunamis in lakes)
Image 12The wave further slows and amplifies as it hits land. Only the largest waves crest. (from Tsunami)
Image 13One of the deep water buoys used in the DART tsunami warning system (from Tsunami)
Image 14Over-riding plate bulges under strain, causing tectonic uplift. (from Tsunami)
Image 15Calculated travel time map for the 1964 Alaska tsunami (in hours) (from Tsunami)
Image 16Lisbon earthquake and tsunami in November 1755 (from Tsunami)
Image 17When the wave enters shallow water, it slows down and its amplitude (height) increases. (from Tsunami)
Image 18Drawing of tectonic plate boundary before earthquake (from Tsunami)
Image 19Plate slips, causing subsidence and releasing energy into water. (from Tsunami)
Image 20Diagram showing several measures to describe a tsunami size, including height, inundation and run-up (from Tsunami)
Image 21Tsunami Early Warning Tower board in Hikkaduwa, Sri Lanka (from Tsunami warning system)
Image 22Tsunami warning system in East Timor (from Tsunami warning system)

Selected tsunami article

A helicopter flies over the port of Sendai to deliver food to survivors of the earthquake and tsunami.

On 11 March 2011, at 14:46 JST (05:46 UTC), a 9.0–9.1 undersea megathrust earthquake occurred in the Pacific Ocean, 72 km (45 mi) east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes and caused a tsunami. It is sometimes known in Japan as the "Great East Japan Earthquake" (東日本大震災, Higashi nihon daishinsai), among other names. The disaster is often referred to by its numerical date, 3.11 (read san ten ichi-ichi in Japanese). (Full article...)

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In the news

3 April 2024 – 2024 Hualien earthquake: A magnitude 7.4 earthquake strikes off the coast of Taiwan, prompting tsunami warnings for Okinawa Prefecture, Japan. A large section of the uninhabited Guishan Island collapses into the ocean. Nine people are killed in Taiwan, including four by rockfalls, with more than 930 others injured. (AP) (Al Jazeera)