A tsunami (from Japanese: 津波, “harbour wave”;[1] English pronunciation: /suːˈnɑːmi/ soo-NAH-mee[2] or /tsuːˈnɑːmi/[3]) or tidal wave,[4], also known as a seismic sea wave, 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.[5] Unlike normal ocean waves, which are generated by wind, or tides, which are generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water.

Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer.[6] Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide.[7] For this reason, it is often referred to as a “tidal wave”, although this usage is not favoured by the scientific community because it might give the false impression of a causal relationship between tides and tsunamis.[8] Tsunamis generally consist of a series of waves, with periods ranging from minutes to hours, arriving in a so-called “internal wave train”.[9] Wave heights of tens of metres can be generated by large events. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous, and they can affect entire ocean basins. The 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history, with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean.

The Ancient Greek historian Thucydides suggested in his 5th century BC History of the Peloponnesian War that tsunamis were related to submarine earthquakes,[10][11] but the understanding of tsunamis remained slim until the 20th century and much remains unknown. Major areas of current research include determining why some large earthquakes do not generate tsunamis while other smaller ones do; accurately forecasting the passage of tsunamis across the oceans; and forecasting how tsunami waves interact with shorelines.



Making Paper from Woodchips


Do you have any paper in your bag? It may seem like a silly question but do you know how to make paper? What is paper made of? Right! And how is about ‘wood chipping’? Have you ever heard about it? Well, wood chipping is a process used to obtain pulp and paper products from forest trees.

First of all, the tops and branches of the trees are cut out and then the logs are taken to the mill. At the mill the bark of the logs is removed and the logs are taken to a chipper which cuts them into small pieces called woodchips. The woodchips are then screened to remove dirt and other impurities. Hmm … at this stage they are either exported in this form or changed into the pulp by chemicals and heat. Oh, I almost forgot, the pulp is then bleached and the water content is removed. Finally, the pulp is rolled out to make paper.

Considering the complexity of making paper, let’s appreciate any paper on our hands. Use it more effectively. Thank you for listening. Bye.



A tsunami is very large sea wave that is generated by a disturbance along the ocean floor. This disturbance can be an earthquake, a landslide, or a volcanic eruption. A tsunami is undetectable far out in the ocean, but once it reaches shallow water, this fast-traveling wave grows very large.

Tsunamis occur when a major fault under the ocean floor suddenly slips. The displace rock pushes water above it like a giant paddle, producing powerful water waves at the ocean surface. The ocean waves spread out from the vicinity of the earthquake source and move across the ocean until they reach the coastline, where their height increases as they reach the continental shelf, the part of the Earth’s crust that slopes, or rises, from the ocean floor up to the land.

Tsunamis wash ashore with often disastrous effects such as severe flooding, loss of live due to drowning, and damage to property.