UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2025-04-04 10:35
 HOME     CONFERENCES     SEARCH            LOGIN     NEW USER     IMAGES   


Conference: Bucharest University Faculty of Physics 2011 Meeting


Section: Atmosphere and Earth Science; Environment Protection


Title:
First digital seismograms of the significant Vrancea historical earthquakes recorded between 1903 and 1940


Authors:
D. Paulescu ,M. Radulian , M. Popa, G. Marmureanu


Affiliation:
National Institute for Earth Physics, 12 Calugareni, PO Box MG-2, 077125, Magurele, Romania


E-mail
dpaulescu@infp.ro,mircea@infp.ro,mihaela@infp.ro,marmur@infp.ro


Keywords:
historical seismograms,digitization,seismograph


Abstract:
“The digital preservation of the unique seismological heritage consisting of historical seismograms and earthquake bulletins, and of related documentation (e.g., observatory logbooks, station books, etc.), is critically important in order to avoid deterioration and loss over time” [Kanamori, 1988].The first available historical seismograms in Romania were recorded at Filaret (Bucharest) seismic station (founded by Stefan Hepites in 1895) by a Bosch seismograph starting with December 1902. The first major earthquake for which we found analytical seismograms (smoked blackened paper) occurred on September 13, 1903. This seismograph is known as the one which recorded one of the five earthquakes used by H. Jeffreys (1935) to demonstrate for the first time, the existence of deep earthquakes. The purpose of the present paper is to convert into digital form a set of historical seismograms recorded in Bucharest Observatory in order to reevaluate the source parameters. The considered events were recorded by different types of instruments (Bosch, Mainka-Demetrescu, Galitin and Alfani) operating in the first half of the XIXth century.The conversion procedure implies three steps: scanning of seismograms at high resolution, cutting of the event waveform in a suitable window and digitization. To perform the digitization we applied GIMP (GNU Image Manipulation) and TESEO2 (Turn the Eldest Seismograms into the Electronic Original Ones) programs. The resulting seismograms are obtained in SAC (Seismic Analysis Code) format.