Large Earthquakes of the World

Summary

The earthquake of March 4, 1977 was one of the largest seismic events occurring in Romania.Its peculiar way of generation an manifestation on the surface gives a lot of information, which being analyzed globally and particularly lead to the knowledge and understanding of certain essential features characterizing the earthquake in Vrancea region.

The 7.2 magnitude earthquake that occurred in the Vrancea region on March 4, 1977 was extremely damaging throughout the country and particularly in Bucharest, Craiova, Zimnicea, Valenii de Munte, Ploiesti and Campina.

In order to estimate the intensity of the seismic shock in Bucharest, some thousand masonry, reinforced concrete frames and large panel buildings, distributed on the whole town area, were examined.

KEYWORDS: Vrancea Earthquake,

1. INTRODUCTION

On Friday, March 4, 1977 at 9:21 P.M. local time a destructive earthquake of magnitude 7.2 occurred in the Vrancea region west of Focsani in the southeast corner of Romanian Carpathian Mountains approximately 150 km northeast of the capital city of Bucharest. There was considerable damage in Bucharest and the town of Craiova, Zimnicea and Alexandria. Over 30 buildings, among which were many five and ten story apartment structures, collapsed in Bucharest.

Statistics on casualties and property damage compiled as of the end of April indicate that the earthquake:

- killed 1.578 people including 1.424 in Bucharest and 154 in the rest of the country

- injured 11.221 including 7.598 in Bucharest and 3.723 in the rest of the country

- destroyed or seriously damaged 33.000 housing units in high-rise apartment flats and conventional type dwellings (35.000 families, more than 200.000 persons homeless)

- caused lesser damage to 182.000 other dwellings

- destroyed 374 kindergartens, nurseries, primary and secondary schools and badly damaged 1.992 others

- destroyed six university buildings and damaged 60 others

- destroyed one orphanage and damaged 15 others

- destroyed 11 hospitals and damaged 228 other hospitals and 220 polyclinics

- destroyed or damaged almost 400 cultural institutions such as theaters and museums

- damaged 763 factories

- directly affected over 200.000 people

There was no evidence of significant overall damage to the country’s infrastructure. Power, water, rail and air service were restored very quickly after the earthquake. Ports were unaffected.

This report summarizes the field investigations conducted by the National Bureau of Standards members of the U.S technical team dispatched to Romania by the

Agency for International Development.

The NBS investigations were confined to Bucharest and the city of Craiova. Their purpose was to assess the performance of buildings and the type of damage which occurred.

2. THE EARTHQUAKE CHARACTERISTICS

According to CSEM (Strasbourg), the earthquake was characterized by the following parameters: latitude, φ= 45o8’ N; longitude, λ= 26o79’ E; depth of hypocenter h= 97 Km; magnitude M=7.2 and origin time, H=19h21m56s07 GMT. According to the geographical coordinates, the earthquake epicenter was located in the curvature area of the Carpathians.

About 250 aftershocks had been recorded in a week to ten days following the main shock. Most had a magnitude below 4; the largest was magnitude 4.5. Information from dr. Karl Fuchs, a German seismologist from Karlsruhe, indicated the epicenters for these aftershocks were moving southward and occurring at depths of about 50 km based on the data obtained from his instruments installed in the epicentral region.

1. George Fattal, Emil Simiu, Charles Culver Observations on the Behavior of buildings in the Romania earthquake of March 4,1977, National Bureau of Standards (U.S) Special Publication 490 Issued September 1977.

2. Glen, V., Bruce, A., Mete, A., Christopher Rojahn Earthquake in Romania Marh 4, 1977:An Engineering Report, National Academy Press Washington, D.C. 1980.

3. Mândrescu, N. The Vrancea Earthquake of March 4, 1977 and the seismic microzonation of Bucharest, Centre for Earth Physics and Seismology, 1978 Bucharest.

4. Mândrescu, N. The Vrancea Earthquake of March 4, 1977: aspects of soil behavior, Centre for Earth Physics and Seismology, 1979 Bucharest.