 PERGAMON Renewable Energy 06 "0888# 388Ð496 9859Ð0370:88:, ! see front matter Þ 0888 Elsevier Science Ltd[ All rights reserved PII]S9859Ð0370"87#99664Ð6 Power spectra analysis for world!wide and North Africa historical earthquakes data in relation to sunspots periodicities M[A[M[ Shaltout a\ \ M[T[Y[ Tadros b \ S[L[ Mesiha a a National Research Institute of Astronomy and Geophysics\ Helwan\ E`ypt b Physics Department\ Faculty of Science\ Mansoura University\ Mansoura\ E`ypt Received 07 June 0887^ accepted 09 September 0887 Abstract In the last three decades\ the in~uence of solar activity on earth seismicity is one of the most important subjects in the _eld of long!term prediction of earthquakes[ In the present work\ the autocorrelation and power spectra analysis were applied for the sequences of sunspots and earthquakes activity[ The used data are the worldwide earthquakes of M - 4\ and the sunspots number R z \ for the period 0892Ð0874[ Both are available from the National Oceanic and Atmospheric Administration NOAA\ Boulder\ Colorado\ U[S[A[ Also\ we restrict our attention to earthquakes in North Africa with two stations\ one at Cairo "Egypt#\ and the other at Alger "Algeria# of M - 3 for the period "0899Ð0875#[ The results indicated the presence of the eleven year cycles of the sunspots into the time of the earthquakes of the North Africa[ Also\ from the worldwide and North Africa earthquakes data a periodicities ranged between 0[90 and 4[4 years are revealed\ which may be linked to a solar activity cycle[ Þ 0888 Elsevier Science Ltd[ All rights reserved[ 0[ Introduction In the last three decades\ many authors have suggested that\ solar activity plays a signi_cant but by no means exclusive role in the triggering of earthquakes[ Simpson ð0Ł found that maximum quake frequency occurs at times of moderately high and ~uctuating solar activity[ Sytinskiy ð1Ð6Ł carried out a series of searches on the  Corresponding author