Showing posts with label seismologist. Show all posts
Showing posts with label seismologist. Show all posts

Friday, September 30, 2016

September 30, 1985 died the American seismologist Charles Francis Richter

Photo: washington.edu

Charles Francis Richter spent much of his life in California, in a vulnerable area in terms of seismic and conducted field studies at Stanford University, while being familiar with data and research Laboratory of seismology in Pasadena .

In one of the rare interviews he gave, Charles Richter testified that he became interested in seismology from a "happy fault". "Honestly I tell you, it was an accident. While working on his doctoral thesis about theoretical physics, Dr. Robert Milikan she had called him into his office and told me that seismology lab looking for a physicist. Even if I was not in the field it seemed interesting to me. Soon I gave up my work and I joined the team of seismologists in 1927 ".



Richter was created in 1935 by Charles Richter and Beno Gutenberg, from the California Institute of Technology and indicates the energy released in an earthquake center. It is a scale logartmică because magnitude after Richter, corresponds to the logarithm of measuring amplitude wave volume (Type P and S), 100 km from the epicenter and is graded from 1 to 9, and the intensity of earthquakes is expressed in numbers fractionation.

In 1956, Richter and Beno Gutenberg, geologist and seismologist German, working at the Institute of Technology of California on a map accurate distribution of earthquakes in the area, improved method for measuring the magnitude, taking into account the waves of volume of propagation speed of which depends on the structure of the earth, which is observed for a period of 20 seconds.


Photo: e-education.psu.edu

Because the Richter scale is a logarithmic scale, a change of one degree is correlated with a change of 10 times the amplitude of the seismic waves and about 30 times the energy that is released by an earthquake. Richter magnitude earthquake has proposed such a measure, based on the maximum amplitude of the seismic waves recorded on a seismogram.

Initially recorded seismographs primary waves, surface, which are the fastest parallel to the propagation direction, as the accompanying noise that can be heard at the start of an earthquake. Secondary waves are transverse, perpendicular to the direction of propagation of the wave and not propagated in liquid media being recorded by seismic equipment later than primary waves. Volume waves can follow very different paths within the ground, depending on the local geology, and therefore do not arrive simultaneously at the same distance on the surface.


Limiting the Richter scale, it is confirmed by the devastating earthquakes over 9.0 degrees, which occurred in the last hundred years Kamtceatka (Russia) in 1952, in Chile in May 1960 in Alaska in 1964 in Sumatra in December 2004, the fourth force destructive of all those known so far in Japan on the Pacific coast in 2011.

Invenit Mundo presents the main historical significance of the day September 30:

1791 - Held at the Vienna premiere of the opera "The Magic Flute" by Mozart.

1924 - was born writer Truman Capote: "Grass Harp," "In Cold Blood," "Breakfast at Tiffany" (d. August 25, 1984).

1931 - Dem Radulescu was born, actor of theater, film and television, a professor at the National University of Drama and Film "I. L. Caragiale "in Bucharest. Among the most popular films in which he played are: series "B. D.," "Veronica", "Spring buds", "Second Fall of Constantinople", "The Secret of Bacchus". It has died in Bucharest on 17 September 2000.

1955 - died in a car accident, actor James Dean, sex symbol of the 50s: "Rebel Without a Cause," "East of Eden" (b. February 8, 1931).
Photo: en.wikipedia.org

1955 - He died Мihail Chekhov, actor, director and Russian writer (n. 1891).
Photo: jewish.ru


2005 - The Danish newspaper Jyllands-Posten published 12 caricatures of the Prophet Mohammed. One of the caricatures was targeting it with a bomb turban shaped wick, so the Prophet by associating it with terrorism. In Islam representation of the Prophet is prohibited.

Other articles on the same theme:


Story source: 


The above post is reprinted from materials provided by Descopera  . Note: Materials may be edited for content and length.