2:15 PM - 2:30 PM
[S04-3-03] THE 7TH JULY, 1923, CANAL DE BERDUN EARTHQUAKE, IN THE PYRENEES. ITS MACROSEISMIC FIELD FROM CONTEMPORARY RECORDS
Seismicity rate in the Pyrenees can be considered moderate. Nevertheless, damaging earthquakes occurs as it is well known from their historical seismicity records. Among them, the 7th July, 1923, known as Canal de Berdun earthquake, is one of the biggest events (maybe the largest one) occurred during the instrumental period in this region. As it occurred in a sector with low population density, and the produced damage was, consequently, moderate, not much attention has been paid to it.
Its size, recently re-estimated from waveform inversion of contemporary seismograms, on the order of Mw 5.4, and unique location among the large earthquakes in the Pyrenees, in the central, south part of the chain, make this event of great interest for a better definition of the regional seismicity. For this reason we decided to study a new its source from the analysis of the available contemporary macroseismic records and related documents.
Observatory Fabra, in Barcelona, preserves a large collection of macroseismic records of earthquakes occurred in the North and East of Spain during the XX Century. Among them, the whole documentation of the survey on occasion of the 7th July 1923 earthquake in the Pyrenees. A detailed reanalysis of these records, complemented with information published in the contemporary press and studies allowed a reconstruction of the macroseismic field in the Spanish side of the Pyrenees. From it macroseismic estimates of the epicentral location and magnitude, in very good agreement with the instrumental ones, are obtained. We present the different steps of the undertaken research, some of the obtained results and its consequences for the regional seismicity and we compare them with present earthquakes occurred in the same region.
Its size, recently re-estimated from waveform inversion of contemporary seismograms, on the order of Mw 5.4, and unique location among the large earthquakes in the Pyrenees, in the central, south part of the chain, make this event of great interest for a better definition of the regional seismicity. For this reason we decided to study a new its source from the analysis of the available contemporary macroseismic records and related documents.
Observatory Fabra, in Barcelona, preserves a large collection of macroseismic records of earthquakes occurred in the North and East of Spain during the XX Century. Among them, the whole documentation of the survey on occasion of the 7th July 1923 earthquake in the Pyrenees. A detailed reanalysis of these records, complemented with information published in the contemporary press and studies allowed a reconstruction of the macroseismic field in the Spanish side of the Pyrenees. From it macroseismic estimates of the epicentral location and magnitude, in very good agreement with the instrumental ones, are obtained. We present the different steps of the undertaken research, some of the obtained results and its consequences for the regional seismicity and we compare them with present earthquakes occurred in the same region.