ISS.CAT = hypocenter file for the International Seismological Summary (1914-1963) ======================================================================== WARNING! This file has been produced by hand-entering in a computer the hypocenters listed in the printed ISS bulletins. Although the entries have been carefully checked, the file can still contain errors (such as typos, missing and/or duplicated events, etc). If you find an error, please report it to the author (address at bottom) so it can be corrected. ======================================================================== This file contains hypocenters of earthquakes listed in the bulletins of the International Seismological Summary (ISS) from 1918 to 1963. In addition, the hypocenters listed in the bulletins of the British Association for the Advancement of Science (BAAS) Seismological Committee (the predecessor of the ISS) for 1914-1917 have also been included. The file ISS.CAT contains only hypocenters of earthquakes that have available phase arrival time data listed in tabular form in the ISS bulletins. Undetermined shocks and earthquakes reported by other agencies without arrival time data are not included in this file. When more than one hypocentral solution was produced for the same event (this practice was only used in the early years of the ISS) we have chosen to list only the first solution, in order to avoid duplicate entries. Although the bulletins of the ISS include hypocentral locations and phase arrival time data, this file contains only hypocenters. A long term project to convert ISS phase data to digital form is currently under way (Villasenor et al., 1997). The ISS bulletins never listed amplitude and period data to calculate magnitudes, and they reported very infrequently magnitudes calculated by other agencies or stations. Therefore the file ISS.CAT does not list earthquake magnitudes. Prior to the bulletin for 1957 the ISS reported focal depth in terms of the fraction of the Earth's radius below the so-called "base of the superficial layers" (33 km for the Jeffreys-Bullen earth model). Starting in the bulletin for 1957, depth is reported as km below the earth's surface. For hypocenters prior to 1957 we have converted the value of the fraction of the Earth's (frac) to depth in km (dep) using the following convention: no frac (shallow or "normal" focus): dep = 0 km frac < 0 (focus "above normal"): dep = 0 km frac >= 0 dep = frac*(6371-33) + 33 km FILE FORMAT =========== year mo dy hr mn sec lat lon dep frac . . . 1927 4 9 8 56 50.00 6.500 126.000 0.0 1927 4 9 16 51 30.00 -21.000 -67.000 95.0 0.0100 1927 4 9 19 5 8.00 17.000 -97.000 0.0 1927 4 11 22 3 40.00 -34.000 57.000 0.0 1927 4 12 23 13 18.00 -18.500 168.500 0.0 1927 4 13 13 44 10.00 15.800 119.400 160.0 0.0200 1927 4 13 14 34 32.00 15.800 119.400 160.0 0.0200 1927 4 14 6 23 28.00 -32.500 -69.500 130.0 0.0150 1927 4 16 8 14 51.00 51.000 -179.500 0.0 1927 4 16 9 11 10.00 -34.000 57.000 0.0 1927 4 16 13 3 35.00 6.500 126.000 0.0 1927 4 17 9 5 42.00 -6.500 126.000 160.0 0.0200 1927 4 18 15 1 45.00 38.500 71.000 0.0 1927 4 19 8 33 42.00 -7.700 106.500 0.0 . . . where: year, mo, day, hr mn, sec = date and time of the origin lat = latitude in degrees (north positive) lon = longitude in degrees (east positive) dep = focal depth in km (before 1957 calculated using frac) frac = focal depth as "fraction of the Earth's radius below the base of the superficial layers" REFERENCES: Villasenor, A., E.A. Bergman, T.M. Boyd, E.R. Engdahl, D.W. Frazier, M.M. Harden, J.L. Orth, R.L. Parkes, and K.M. Shedlock, Toward a comprehensive catalog of global historical seismicity, Eos Trans. AGU, vol. 78, no. 50, pp. 581, 583, 588, 1997. -- Antonio Villaseñor Institute of Earth Sciences "Jaume Almera" - CSIC Lluís Solé i Sabarís s/n ph: +34 - 93 409 5410 (x. 244) 08028 Barcelona fax: +34 - 93 411 0012 SPAIN email: antonio@ija.csic.es