| O grande terramoto de Lisboa by Helena Carvalhão Buescu, Gonçalo Cordeiro - 2005 - 638 pages |
| O terremoto do 1. ̊ de Novembro de 1755 em Portugal, e um estudo demográfico by Francisco Luiz Pereira de Sousa - 1919 |
| Oaxaca, Mexico, earthquake of 29 November 1978 by Lautaro Ponce Mori - 1979 - 54 pages |
| Observaciones geológicas en una ascención al Citaltépetl (pico di Orizaba) by Ernesto Angermann - 1904 - 369 pages |
| Observations on the earthquake of May 26, 1909 by Johan August Udden - 1910 - 162 pages |
| Observations on the Guatemalan earthquake relief effort, Agency for International Development, Department of Defense, Department of State by United States. General Accounting Office - 1976 - 40 pages |
| Observations on the Guatemalan earthquake relief effort, Agency for International Development, Department of Defense, Department of State by United States. General Accounting Office - 1976 - 40 pages |
| Ocean bottom seismometer measurements on the Gorda Ridge by L. Dale Bibee, Oregon. Dept. of Geology and Mineral Industries, Gorda Ridge Technical Task Force - 1986 - 25 pages |
| Oceanographic papers by Miguel Selga - 1931 - 195 pages |
| Oceanographic, geologic and engineering studies of the Chilean earthquake of May 1960 by Earthquake Engineering Research Institute, Seismological Society of America - 1963 - 338 pages |
| Official report of Capt. S. Robinson, R.N.R. by Samuel Robinson - 1924 - 24 pages |
| Oklahoma earthquakes - 1990 - 7 pages |
| On earthquake epicentres and earthquake shocks between 1913 and 1938 in the region between 00 and 300N and 560 and 1200W by Louis Rutten, B. van Raadshooven - 1940 - 44 pages |
| On observation of earthquake phenomena. By R. Mallet ... by Robert Mallet - 1859 - 40 pages |
| On Shaky Ground by Norma Hayes Bagnall - 1996 - 128 pages |
| On shaky ground by John J. Nance - 1988 - 416 pages |
| On syntheses of ground motions from earthquakes by Dimitrios Anastasios Sotiropoulos - 1983 - 210 pages |
| On the annual and semi-annual seismic periods by Charles Davison - 1894 - 63 pages |
| On the cause of the great earthquake in central Japan, 1891 by Bundjirô Kotô - 1893 - 353 pages |
| On the earthquake shocks experienced in the Edinburgh district on Friday, January 18, 1889 by Ralph Richardson - 1889 - 12 pages |
| On the four-year seismic period by Georges G. Dubourdieu - 1972 - 35 pages |
| On the gaseous products of the Krakatoa eruption, and those of great eruptions in general by Joseph Patrick O'Reilly - 1886 - 14 pages |
| On the nature of background seismic motions by Hugh Bradner, Michael Stephen Reichle - 1972 - 8 pages |
| On the propagation of tremors over the surface of an elastic solid by Horace Lamb - 1904 - 42 pages |
| On the risk of liquefaction of buffer and backfill by Roland Pusch - 2000 - 62 pages |
| On the statistics of El Niño occurences and the relationship of El Niño to volcanic and solar/geomagnetic activity by Robert M. Wilson, George C. Marshall Space Flight Center - 1989 - 54 pages |
| On the structure of lavas which have consolidated on steep slopes by Sir Charles Lyell - 1859 - 86 pages |
| On the volcanoes and volcanic phenomena of the Hawaiian Islands by James Dwight Dana, Edward Salisbury Dana - 1889 - 220 pages |
| On the volcanoes and volcanic phenomena of the Hawaiian Islands by James Dwight Dana, Edward Salisbury Dana - 1887 - 220 pages |
| Ondes T dans la Mer des Antilles by Jean Aubrat - 1965 - 191 pages |
| Operation Helping Hand by Truman R. Strobridge - 137 pages |
| Optical levelling tilt stations in the vicinity of Krafla and the Krafla fissure swarm by Eysteinn Tryggvason, Nordic Volcanological Institute - 1995 - 218 pages |
| Organización del servicio sísmico y sus primeros resultados (noviembre de 1907 à diciembre de 1908) by Galdino Negri - 1909 - 54 pages |
| Origin and development of craters by Thomas Augustus Jaggar - 1947 - 508 pages |
| Origin of Earthquakes by Cambridge University Press, Davidson - 2003 |
| Originations of life from volcanoes and petroleum by Donald E. Tyler - 1983 - 128 pages |
| Our mobile earth by Reginald Aldworth Daly - 1926 - 342 pages |
| Our record of Canadian earthquakes by Clement Henry McLeod, Hugh Longbourne Callendar - 1897 - 326 pages |