Cosimo De Giorgi e l’Abruzzo: ricerche geologiche e sismologiche tra 1876 e 1887

De Giorgi’s scientific activity in Abruzzi is mainly related to the geological surveys in the second half of the 1870s and to the involvement in the discussion about seismology in 1887, during the First Geodynamic Congress held in L’Aquila. Two scientific contributions on Bollettino del Regio Comitato Geologico d’Italia, published in 1877 and 1878 respectively, summarize the activity of 1870s. The former is related to geological investigations in the Pescara and Aterno river valleys, while the latter is the report of surveys in the area of Campo Imperatore (Gran Sasso chain) for the identification of lignite seams and bituminous schists potentially exploitable for industrial purposes. The work De Giorgi made at L’Aquila in 1887 is summarized in the text of the closing conference at the Geodynamic Congress, which gave him the opportunity to address arguments of overriding importance for Seismology at that time. Some of the points in De Giorgi’s discussion are still relevant today, as the earthquake prediction and the defense against the seismic damage by using appropriate building techniques. In the whole, summaries of the performed activities, considerations and conclusions reported in the publications give us the image of De Giorgi as a cutting-edge researcher, a leading representative of Earth Sciences in the second half of the 19th century, for both the methodological approach and the deep knowledge of the theories governing geology and seismology at that time.