The earthquake sequence of May 1951 at Jucuapa, El Salvador

Three earthquakes that happened over two days in May 1951 caused extensive damage to villages in a small area of eastern El Salvador (Central America). Contemporary hypocentral solutions indicated focal depths, confirmed by re-calculations using available seismic data, of the order of 90 km, suggesting events associated with the subducted Cocos plate. Macroseismic observations strongly indicate that the earthquakes were of very shallow focus and this is supported by wave-form modeling and the appearance of seismograms recorded in Guatemala. A re-evaluation of the location and source characteristics for these events is presented, together with a fault plane solution and additional macroseismic evidence. The implications for seismic hazard and risk assessment in Central America, where shallow earthquakes of moderate magnitude, frequently occurring in clusters, pose the greatest threat to settlements which, like the area affected by these events, are concentrated along the axis of Quaternary volcanoes.     

Earthquake data review and seismic hazard analysis for the Hong Kong region

This paper presents the results of a review of earthquake data and a study of seismic hazard for Hong Kong. A region of about 660 km × 660 km around Hong Kong was selected for the study. In this study, the earthquake information available for the region was reviewed, and where possible, earthquake magnitudes were calculated. Since there is no strong motion record for any earthquake within the region, Joyner and Boore's attenuation law¹ has been used for the analysis. The results show that the seismic hazard in Hong Kong is relatively small, but because of the uncertainty inherent in the assumed attenuation relationship, accurate prediction of peak ground acceleration is not possible.     

The earthquake of 1546 in the Holy Landz

The earthquake of 1546 is considered to be one of the largest shocks in the Middle East associated with surface faulting and great loss of life. The examination of contemporary documents shows that this seismic event was a medium magnitude earthquake of M_s about 6.0, in many respects similar to that of the earthquake of 1927, that is, one of those early and grossly exaggerated events which excited widespread interest rather on account of the geographical location than because of their size or special violence. We cpud find no evidence of faulting or excessive damage and no justification to regard this earthquake as one of the most destructive in the Jordan Rift Valley.     

Seismic sea-waves in the Marmara Sea region during the last 20 centuries

An examination of historical sources confirms thatrelatively little can be found about seismic sea-waves in the Marmara Searegion. We find that during the last 20 centuries there have been 16earthquakes which seem to be associated with seismic sea-waves, six ofwhich were damaging. Most of these events were reported from the northcentral and north-east coast of the Sea of Marmara and from the Gulf ofIzmit, from where there is some evidence that the source mechanism ofsome of them was coastal mass failures and sliding of submarine sediments.Another 16 sea-waves reported in literature are found to be spuriousevents.