A careful and intensive study of historical sources and a review of the instrumental data of this century have led to this detailed catalogue of earthquakes. Egypt, Arabia, the Red Sea region and the surrounding areas of Libya, Sudan and Ethiopia are studied from the earliest times to the present day. Each earthquake is described as fully as possible from the available data, and is analysed in a geographical and historical context. The completeness of the earthquake catalogue over time is analysed and the range of sources and problems associated with the scrutiny of historical sources is discussed. The information is then placed in a geophysical framework.

Inconsistencies have become apparent in locations allocated to subcrustal earthquakes beneath the main seismic region of New Zealand. To reduce these, a simple model has been set up in which velocities are increased along ray paths presumed to be entirely in the zone of deep earthquakes. The results are most consistent when the velocities of both P and S waves are increased by 11%, compared with the standard Jeffreys-Bullen model. The effect of this velocity change is to reduce the dip of the zone of subcrustal foci determined in previous studies, and to make the foci more closely planar. The newly defined plane strikes N 45° E and dips at 50° to the north·west.

S U M M A R YWe have collected and re-examined macroseismic information for large Central American earthquakes since the beginning of the period of instrumental recording about one hundred years ago, and combined this with a reassessment of early instrumental information to produce a catalogue of 51 events that we believe includes all those with magnitudes (Ms) greater than 7.0. We have reassessed surface-wave magnitudes by consulting station bulletins and we have derived a correction that gives an equivalent Ms for events of intermediate depth. We have also developed a regional relationship between Ms and seismic moment, which enables us to estimate the seismic slip rate across the Middle American Trench. Our best estimates give an average slip rate several times smaller than suggested convergence rates, but with the seismic slip in the central segment of the trench almost an order of magnitude smaller than that in the segments on either side. The low seismic slip rate may indicate aseismic crustal deformation

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