See: Earthquake, Siesmograph, and History of Seismograph

373 B.C.  Earthquake of Helice, Greece.

132 A.D.  Chang Heng, seismoscope.

1556  Chinese earthquake; 830,000 deaths reported.

1707 - October 28  Great Japanese Earthquake.

1755 - November 1  Lisbon Earthquake.

1783 - February 5 and following. Earthquakes of Calabria, Italy, scientific field investigation.

1819 - June 16  Earthquake of Cutch, India; observed faulting (Allah Bund).

1830  Lyell, Principles of Geology, first edition.

1846  Robert Mallet; his first general paper on earthquakes.

1855  Kreil, early seismograph.

1855 - January 24  New Zealand earthquake; observed faulting.

1857 - January 9  California (Fort Tejon) earthquake; observed strike-slip.

1857 - December 16  Earthquake in Italy (Kingdom of Naples); Mallet, field investigation.

1865  Seismological observations begun at Manila (with seismoscopes; seismographs installed 1881-1889).

1872  - March 26  Earthquake in Owens Valley, California; observed scarps a nd strike-slip.

1879  Seismographs developed in Japan by the British group.

1880  Seismological Society of Japan organized.

1883  August 27. Explosion of Krakatoa.

1884  Rossi-Forel intensity scale set up. Seismological service established at manila.

1885  Lord Rayleigh, paper on theory of "Rayleigh waves."

1887  Voigt, investigation of elasticity of crystals; definition and naming of tensors. Rudolph, first paper on seaquakes. Seismological stations established in California at Berkeley and Lick Observatory.

1888 - September 1  Amuri earthquake, New Zealand; strike-slip offsetting fences.

1889 - April 18  First seismogram of a teleseim identified.

1891 - October 28  Mino-Owari earthquake, Japan; large strike-slip and dip slip.

1892  Japanese Imperial Earthquake Investigation Committee established.

1892 - May 17  Sumatra Earthquake; strike-slip shown by triangulation survey.

1894  New seismographs developed by Vincentini (Padua, Italy) and by Milne in England.

1896  Seismology Committee of the British Association for the Advancement of Science organization.

1897 - June 12  Great earthquake of Assam, India ; investigation by Oldham.

1898  Seismograph developed by Omori at Tokyo. Stations with milne instruments initiated at Wellington (New Zealand) and Batavia (Java).

1899  Knott's equations for reflection and refraction coefficients of elastic waves.

1899 - September 3 and 10  Great Alaskan earthquakes, uplifts reaching 47 feet.

1901  Inverted pendulum seismograph developed by Wiechert. Geophysical Institute founded at Gottingen.

1903  International Seismological Association organized.

1904  Seismological station initiated at Uppsala (Sweden).

1906  Galitzin electromagnetic seismograph developed (Russia). Vertical-component seismograph set up by Straubel and Eppenstein at Jena (Germany).

1906 - January 21  Major deep-focus earthquake under Japan.

1906 - January 31  Great earthquake, Columbia and Ecuador.

1906 - April 18  California earthquake; great extent of strike-slip faulting; survey re-triangulation leading to elastic-rebound theory of earthquakes.

1907  Seismograph developed by Mainka at Strassburg.

1908 - June 30  Great Siberian meteorite fall.

1909  Seismological station established at Riverview near Sydney, Australia.

1909 - October 8  Earthquake near Zagreb, Croatia; discovery of the subcrustal discontinuity by A. Mohorovicic.

1910  New instruments at Berkeley.

1911  Seismological Society of America founded; it's Bulletin began publication. New instruments at Lick OBservatory Station. Galitzin vertical-component seismograph developed (Russia). Theory of Love waves.

1913  Station established at La Paz, Bolivia. radius of the core determined by Gutenberg at Gottingen.

1915  Milne-Shaw seismograph developed by J.J. Shaw (England).

1918  First year covered by International Seismological Summary.

1919  Zoeppritz equations for coefficients of reflection and refraction of elastic waves published (posthumously).

1921  Carnegie Institution of Washington, Advisory Committee in Seismology appointed.

1921 - September 21  Explosion at Oppau, Germany.

1922  Changes in the variation of latitude and in other geophysical elements.

1923  Wood-Anderson torsion seismometers began regular recording (Pasadena).

1924  Nikiforov torsion seismographs in the service (USSR).

1925  Jesuit Seismological Association organized; headquarters at St. Louis. Seismological work transferred from U.S. Weather Bureau to Coast and Geodetic Survey.

1925 - June 29  Santa Barbara earthquake.

1926  Geophysical Magazine (Tokyo) began publication. Earthquake department of Pacific Board of Fire Underwriters established.

1927  Seismological Laboratory at Pasadena occupied.

1927 - March 7  Tango earthquake (Japan); thoroughly investigated; two fault traces.

1928  K. Wadati, paper on shallow and deep earthquakes.

1929  New electromagnetic seismograph developed by Wenner.

1929 - June 17  New Zealand Earthquake; expansion of new Zealand seismology followed.

1931  Variable-reluctance seismometer developed by Benioff (Pasadena).

1932  Benioff strain seismometer developed. U. S. Coast and Geodetic Survey initiated a program of strong-motion recording in California.

1933 - March 3  (Japanese date). Great Sanriku earthquake and tsunami.

1934  P'P' and relate waves discovered at Pasadena.

1935  Magnitude scale published.

1936  Existence of the inner core suggested by Miss Lehmann in Copenhagen.

1937  Istituto Nazionale di Geofisica established; headquarters at Rome.

1939 - December 27  Destructive earthquake in Turkey, first of a series extended and connected faulting.

1940  T wave described and named by Linehan in Weston, Massachusetts.

1944  Annals de Geophysics began publication.

1946 - April 1  Aleutian tsunami, destructive on Hawaii; seismic sea warning service organized in consequence.

1946 - July 24  Atomic bomb test at Bikini; P waves recorded at distant stations.

1947 - April 18  Hegelian demolition.

1948  C. A. Whitten (U.S. Coast and Geodetic Survey), paper on continuing horizontal displacements in California.

1949  Annali di Geofisicia began publication.

1949 - August 6  Large quarry blast at Corona, California.

1950 - August 15  Great earthquake, Tibet and Assam.

1951  Strain-release curves developed by Benioff in Pasadena.

1952  Lg waves discovered by Ewig and Press in at Columbia University, New York.

1953  Pa and Sa waves discovered by Caloi at Rome and independently by Ewig and Press.

1954 - March 29  Earthquake 640 kilometers deep under Spain.

1954 - December 16  Major earthquake in Nevada; large and extensive faulting.

1957 - July 1 to 1958 - December 31  International Geophysical Year.

All information adapted from Elementary Seismology, written by Charles F. Richter, published by W. H Freeman & Company, Inc, 1958.