Iberian seismicity, 1961 - 1965

Abstract

This paper compares tlie seismic results corresponding to 1961-65 with those presented in several a u t h o r ' s prior studies for the I b e r i a n Peninsula region, which were obtained reducing to a 50 y e a r period t h e available seismic material up to 1960. The present paper lists 237 e a r t h q u a k e s , a selection between those occurred and recorded; their epic e n t r a l coordinates, origin time, depth and magnitude f r om body waves; and a discussion about t h e seismically active quadricles on t h e area, regional density, epicenter display, annual frequency in steps of % m> t h e parabolic a d j u s t m e n t for log N, m, tectonic flux and i n t e r m e d i a t e foci location rel a t e d with the main tectonic features. 1961-65 is a t e n t h of t h e foresaid reduced 50 Y.P. and the present r e s u l t s agree with t h e preliminary ones, as it was expected; mainly for the following features: a) migration of maximal density which is Easterly; b) a s a t i s f a c t o r y parabolic regression for log JVT, m; c) t h e cyclic appearance r e g a r d i n g annual frequency v a r i a t i o n ; d) continuation of the accumulative behaviour for the strain release curve during the present period, which began in 1954; e) seismicity is significatively of an i n t r a l p i n e character, and /) i n t e r m e d i a t e foci (preliminary determinations) laying out by line with both: Guadalquivir Fault, SW extension, and Alboran Sea's bottoms