Overview of Part I

Abstract

The seismic activity in Romania is dominated by the earthquakes generated at intermediate depths (60÷180 km) in the Vrancea region, located at the bend of the South-Eastern Carpathians. The seismicity concentrates in a narrow high-velocity lithospheric volume embedded in the upper mantle. The rate of seismic moment per volume, ~ 0.8 x 1019 Nm/yr, is comparable to southern California (Wenzel et al., 1998). The event produced on 10th November 1940 (Mw = 7.7) was the largest instrumentally recorded earthquake in Romania, was felt in several other countries ( Bulgaria, Republic of Moldova, Ukraine, Russia, Greece, Turkey, Hungary, Yugoslavia, etc.) and produced victims and damage on a wide area beyond Romania’s borders. The large magnitude, the huge macroseismic field (with seismic intensities reaching X), the relatively large number of victims, altogether rank the Vrancea 1940 earthquake as one of the major European seismic events.

Appendix: Summary of the Papers in this Chapter

The paper by Marmureanu et al. introduces a brief presentation of the seismicity of Vrancea source before the November 10th, 1940 earthquake. An important part of the paper is devoted to the description (data selected from various sources) of the earthquake effects in Romania, focusing on several cities which experienced extensive damage (Barlad, Ploiesti, Bucharest, Targoviste, Buzau). The paper ends by presenting data on earthquake damage of a number of churches and monasteries in Romania, the authors estimating MSK seismic intensity values at the sites of damaged religious buildings.

The paper of Calotescu et al. begins with the presentation of the evolution of seismic design of buildings in Romania with emphasis on Bucharest, “Europe’s capital of earthquakes” (The Guardian, March 25th 2014, online edition). Following 1940 Vrancea earthquake, new seismic design regulations (1941, 1945) were prepared (but not enforced) and macroseismic hazard maps were documented. In the paper the most representative macroseismic maps available to the authors compared and discussed. Seismological data available before and after the Nov. 10th, 1940 event and data related to the damage produced by historic strong Vrancea earthquakes (1802, 1838, 1940) are presented and discussed.

The paper of Georgescu focuses on the complete collapse during the November 10th, 1940 earthquake of Carlton building in Bucharest. With about 45 m height, the modern Carlton building was one of the symbols of the capital city Bucharest and was a representative work of avant-garde architecture. Located in the city center, the building had a reinforced concrete frame structure with in filled masonry walls. Using an extensive bibliographic documentation (from Romania, Germany, Belgium and France), the paper describes the possible collapse mechanism and the Search and Rescue operations.

The paper of Petrovici begins with a historical overview on the seismicity and on the reinforced concrete design and construction in Romania. The paper continues with the presentation of the main aspects of architectural and structural building design in Romania prior to the 1940 earthquake and ends with a critical analysis of the main post-earthquake lessons from Beles (1941a, b), with elements concerning the 1977 earthquake effects and with a warning for the potential damage during a future strong earthquake.

The paper of Bala and Toma-Danila is structured in two main parts: one devoted to the seismological aspects of the November 10th, 1940 earthquake and its effects in Romania (with special emphasis on the paper of Beles (1941a, b), on the conclusions and recommendations that were made) and other devoted to the seismological aspects of the March 4th, 1977 earthquake and its effects in Romania. The authors underline the link between the 1977 collapses and the damages from 1940, in Bucharest and the lessons to be considered for preventing future earthquake effects.

The paper of Vlad discusses the seismic event of November 10th, 1940 in the light of “seismic islands”, situated far away from the vicinity of the located epicentre of the earthquake. In this respect, the most representative example is that of Bucharest, located nearly 160 km from the epicentre, and where the macroseismic intensity was set to IX, according to the seismic intensity scale of G. Mercalli and processed by A. Sieberg. The paper focuses on the relevant issues regarding the design and construction practices of the building categories that were severely damaged by the destructive 1940 Vrancea earthquake.

In the paper of Stepanenco and Cardanet the available macroseismic data to the northeast of the epicentre of November 10th 1940 Vrancea earthquake are analyzed. As a result of the previously-mentioned analysis and through the generalization of macroseismic information contained in the relevant literature, a new table with intensity values for the territory of Moldova, Ukraine and Russia was developed, and the isoseismal map of this earthquake are re-drawn. The macroseismic effects for the Eastern Europe of the Vrancea earthquakes of January 23, 1838, March 4, 1977, August 30, 1986 and May 30, 1990 are compared and discussed.