impact depth
71Ocean acidification — Change in sea water acidity pH caused by anthropogenic CO2 between the 1700s and the 1990s Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth …
72World War I — This article is about the major war of 1914–1918. For other uses, see World War One (disambiguation) and Great War (disambiguation). World War I …
73Asia — /ay zheuh, ay sheuh/, n. a continent bounded by Europe and the Arctic, Pacific, and Indian oceans. 2,896,700,000; ab. 16,000,000 sq. mi. (41,440,000 sq. km). * * * I Largest continent on Earth. It is bounded by the Arctic Ocean, the Pacific Ocean …
74Italy — /it l ee/, n. a republic in S Europe, comprising a peninsula S of the Alps, and Sicily, Sardinia, Elba, and other smaller islands: a kingdom 1870 1946. 57,534,088; 116,294 sq. mi. (301,200 sq. km). Cap.: Rome. Italian, Italia. * * * Italy… …
75canals and inland waterways — ▪ waterway Introduction natural or artificial waterways used for navigation, crop irrigation, water supply, or drainage. Despite modern technological advances in air and ground transportation, inland waterways continue to fill a vital …
76Shaped charge — Sectioned high explosive anti tank round with the inner shaped charge visible …
77Motorcycle helmet — A collection of motorcycle helmets worn by Moto GP racer Valentino Rossi A motorcycle helmet is a type of protective headgear used by motorcycle riders. The primary goal of a motorcycle helmet is motorcycle safety to protect the rider s head… …
78Reflection seismology — (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth s subsurface from reflected seismic waves. The method requires a controlled seismic source of energy,… …
79theatre — /thee euh teuhr, theeeu /, n. theater. * * * I Building or space in which performances are given before an audience. It contains an auditorium and stage. In ancient Greece, where Western theatre began (5th century BC), theatres were constructed… …
80arts, East Asian — Introduction music and visual and performing arts of China, Korea, and Japan. The literatures of these countries are covered in the articles Chinese literature, Korean literature, and Japanese literature. Some studies of East Asia… …
