Ambraseys N.N 1991 <p>Twenty years have elasped since the first issue of Earthquakes &amp; Volcanoes. Apart from the remarkable increases in the number of scientists actively enagaged in earth sciences, what are the outstanding achievements during the past 20 years in the field of engineering seismology, which is my own speciality?</p> application/pdf en U.S Geological Survey Engineering seismology article