IAG-IASPEI 2017

講演情報

Oral

IASPEI Symposia » S05. Preservation and usage of analog seismogram archives

[S05-2] Preservation and usage of analog seismogram archives II

2017年8月4日(金) 10:30 〜 12:00 Room 403 (Kobe International Conference Center 4F, Room 403)

Chairs: Paul Richards (Columbia University, New York) , Graziano Ferrari (National Institute of Geophysics and Volcanology)

11:00 〜 11:15

[S05-2-03] Instrumental polarities of the most important historical seismographs of the Euro-Mediterranean area

Graziano Ferrari, Barbara Palombo, Rodolfo Console, Paola Vannoli (Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy)

One of the many critical issues in the use of historical seismograms is the knowledge of the polarity of the seismographs with mechanical and galvanometric recording system.
This information is not easy to find and rarely appears in the seismological literature or seismic bulletins. Periodical collection, on a global scale, of this and other information of instrumental parameters is not always reliable or it do not refer to the same definition of polarity.
The considerable efforts to use scientifically historical instrumental records (i.e. pre-WWSSN), to calculate for example the focal mechanism are often made vain due to the uncertain reliability of information on the polarity of the historical instruments.
For the most popular historical instruments that have operated in the Euro-Mediterranean during the period 1910 – 1980 we determined the instrumental polarity comparing those expected for a set of 10 earthquakes of known mechanism with those read on over 700 seismograms.