Main Characteristics of November 10, 1940 Strong Vrancea Earthquake in Seismological and Physics of Earthquake Terms

Abstract

Vrancea earthquake on November 10th, 1940 (MW = 7.7; MGR = 7.5; h = 150 km; E = 1.122 × 1023 ergs, Imax = IX½) represents the first large earthquake in the last century and was preceded by other earthquakes as: October 22, 1940 (MW = 6.5) and November 8, 1940 (MW = 5.9). If recorded, it would be given the opportunity to get basic data for seismic hazard assessment and useful conclusions for seismic design of structures to strong earthquakes. Unfortunately, no seismic ground motion was recorded and, as a consequence, no improvements of the Romanian design building code were made after this earthquake. The earthquake of November 10, 1940 confirms the existence of deep earthquakes in Vrancea area, deeper than Moho discontinuity in the lower lithosphere, and this theory was developed for the first time by H. Jeffreys in 1935. Focsani city and several municipalities (Cotesti, Panciu etc.) were almost destroyed and the houses not taller than one floor, were completely damaged. More than 45 churches and monasteries were damages, destroyed or demolished. New data regarding damages at monasteries have been synthesized and analyzed, the resulting intensities are completing the known macroseismic field and data may be used to construct the isoseismic map of the maximum possible Vrancea earthquake.