Some Earthquakes Registered, in 1937

Abstract

WE have received from Dr. W. Hiller the da concerning earthquakes registered at Stuttgart, Ravensberg and Messtetten-Ebingen in 1937. Stuttgart is now equipped with three Galitzin-Wilip seismographs orientated north-south, east-west, and vertical, one Wiechert vertical seismograph of mass 1,320 kgm., two Mainka seismographs of mass 450 kgm. set north-south and east-west, a seismograph of mass 80 kgm. orientated oast-west and a horizontal Wiechert instrument of mass 17,000 kgm. Ravens-berg has two Mainka pendulums of mass 450 kgm. orientated north-south and east-west, and two Conrad seismographs of 23 kgm. also set north-south and east-west. Messtetten-Ebingen is equipped with one vertical Wiechert instrument of mass 80 kgm., and two horizontal pendulums of mass 80 kgm. orientated north-south and east-west. The full list of constants for all these instruments is given. The main part of the report concerns the 426 earthquakes registered at these stations during 1937. For each shock recorded a full list of readings, including date, registering station, component, phase, arrival time, period, amplitude in [i, and remarks chiefly concerning the epicentre and epicentral distance from the station, is given. Lastly, there follow two valuable additions to the compilation. First comes a tabulation of microseisms registered on the Galitzin-Wilip seismometers at Stuttgart, including the period and amplitude in u. on the three components, and secondly a careful study of the Hohenzollernalb earthquake of June 17, 1937. The epicentre of this is found to be 48° 15-3′ N., 9° 12-4′ E., ±2-3 km., depth of focus 19-20 km. ± about 4 km., and Tt 9 h. 56 m. 41-8 s.± 0-3 s. The publication forms a very valuable addition to the data and literature of seismology.