The great personages of Seismology

Chang Heng

Created in 132 A.D. the seismoscope, which is considered to be the first device to detect earthquakes.

John Milne (1850 - 1913)

British, lived most of his life in Japan. He is regarded as the father of modern Seismology.

Giuseppe Mercalli - Seismologist

Italian, constructed his first intensity scale in 1902. Later on, it was improved, since it started to have 12 degrees of intensity and was renamed 1931 Mercalli Modified Scale.

Boris Borisovich Golitzin (1862 – 1916)

He designed and constructed in 1906 the first electromagnetic seismograph with photographic recording. He was a prince to the Czars' royal family.

Andrija Mohorovicic (1857 – 1936)

Croatian, professor at the University of Zágreb, discovered in 1909 the discontinuity between the crust and the mantle which takes his name.

Beno Gutenberg (1889 – 1960)

A remarkable German seismologist. He created a diversity of mathematical models for the Earth, based on the study of the seismic waves. He discovered, in 1914, the Mantle-Core discontinuity that is named after him.

Charles Richter (1900 – 1985)

In 1935, while studying the seisms of southern California, he introduced the magnitude concept, on observing that earthquakes, not matter how far they were from the station, displayed a constant variation in terms of the maximum amplitude registered in the seismograms. To make his scale functional, Richter used the logarithmic concept and borrowed the term “magnitude” from Astronomy.

The magnitude scale can be calculated directly from the seismograms and offers a quantitative description of the earthquake's energy. It is limitless, but in practice, the biggest earthquakes come close to the 9.0 degree. “This is Earth's limitation, not the scale's", said Richter.

Hugo Benioff (1894 – 1968)

He projected and constructed, in 1936, the first strainmeter, a device to measure deformations (contraction or dilatation) of the earth crust.

Sir Harold Jeffreys (1891 – 1989)

Creator of advanced mathematical methods to study geodynamic problems. Cam K. Bullen developed, in 1939, the Time x Distance table, which is still used today. The folowing sentence is his: “If Geophysics needs to use mathematics for the sake of it, it's the Earth's responsibility, not the geophysicist's ”.

Ingle Lehmann (1888 – 1993)

Danish seismologist. Discovered, in 1936, the existence of the Earth's Inner Core. She inferred that inside the planetary core there was a more central geosfera, the Inner Core, where PKP waves' velocity is faster than in its outer part. The Inner Core has a 1.216 km radius.

Kiyoo Wadati (no picture)