1990 Manjil-Rudbar earthquake
The 1990 Manjil-Rudbar earthquake occurred on Thursday, June 21, 1990 at 00:30:14 local time in northern Iran. The shock had a moment magnitude of 7.4 and a Mercalli Intensity of X (Extreme). The National Geophysical Data Center estimated that $8 billion in damage occurred in the affected area. Other earthquake catalogs presented estimates of the loss of life in the range of 35,000-50,000, with a further 60,000-105,000 being injured.
Gardiner Dam opened
The Gardiner Dam on the South Saskatchewan River in Saskatchewan is the third largest embankment dam in Canada and one of the largest embankment dams in the world. Construction on Gardiner Dam and the smaller Qu'Appelle River Dam was started in 1959 and completed in 1967, creating Lake Diefenbaker upstream and diverting a considerable portion of the South Saskatchewan's flow into the Qu'Appelle River. The dam rises 64 metres (209 feet) in height, is almost 5 km (3.1 mi) long and has a width of 1.5 km (0.93 mi) at its base with a volume of 65,000,000 cubic meters.
Iosif Vorovich was born
Iosif Izrailevich-Girshevich Vorovich as a Soviet and Russian mathematician, scientific engineer, author and was made a member of the Russian Academy of Sciences in 1970. He was a specialist in continuum mechanics and the theory of elasticity. In 1971, Vorovich founded the Research Institute of Mechanics and Applied Mathematics at Rostov State University, Rostov-on-Don, now part of the Southern Federal University, Russia.
Pier Luigi Nervi was born
Pier Luigi Nervi was an Italian engineer and architect. He studied at the University of Bologna graduating in 1913. Nervi taught as a professor of engineering at Rome University from 1946 to 1961 and is known worldwide as a structural engineer and architect and for his innovative use of reinforced concrete, especially with numerous notable thin shell structures worldwide.
Charles Ellet Jr. died
Charles Ellet Jr. was an American civil engineer from Pennsylvania who designed and constructed major canals, suspension bridges and railroads. He built the Wheeling Suspension Bridge, the longest suspension bridge in the world from 1849 to 1851. He conducted the first Federal survey of the Mississippi and Ohio rivers as part of the U. S. Army Corps of Engineers.
Siméon Denis Poisson was born
French mathematician and physicist Siméon Denis Poisson contributed on various areas like statistics, complex analysis, partial differential equations, the calculus of variations, analytical mechanics, electricity and magnetism, thermodynamics, elasticity, and fluid mechanics. Poisson's well-known generalization of Laplace's second order partial differential equation is known as Poisson's equation after him.
