1990 Vrancea earthquakes

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1990 Vrancea earthquakes
1990 RO quake.jpg
Epicenter of main shock
Date 30/31 May 1990
Magnitude 6.7 Mw, 6.1 Mw
Depth 89 km
Areas affected Romania
Bulgaria
Moldova
Total damage 16 million US$ in Romania
2 million US$ in Bulgaria
2 million US$ in Moldova
24 million US$ insured losses in Romania
Max. intensity VIII
Landslides Yes
Aftershocks 80
Casualties 14 dead, 362 injured

The 1990 Vrancea earthquakes were three earthquakes on 30 and 31 May 1990 measuring 6.7 and 6.1 on Richter scale, that struck the Romanian county of Vrancea, on two consecutive days.[1] Severe damage in the Bucharest-Brăila-Brașov area was reported and dozens of casualties in Romania and neighbouring Moldova, Ukraine and Bulgaria.

The seismic doublet of May 1990 consisted of two mainshocks occurred at a distance of only 13 hours.[2] The first mainshock took place in the afternoon of 30 May 1990, at 13:40:06 (local hour). The epicenter was located in the northeastern part of the Vrancea Mountains (45°54′N 26°54′E / 45.9°N 26.9°E / 45.9; 26.9), at a depth of 89 km. The earthquake had a magnitude of MGR = 6.7 or Mw = 6.9, the intensity in the epicentral area being of VIII degrees on the Mercalli scale, and VII degrees in Bucharest.[2] On the morning of 31 May 1990, at 3:17 (local hour), occurred the second mainshock, at a depth of 79–86 km, having the magnitude MGR = 6.1 or Mw = 6.3.[2] The event was felt in the epicentral area with an intensity of VII degrees on the Mercalli scale, and VI degrees in Bucharest; likewise, the quake was felt strong enough in Dobrogea.

In the USGS EXPO-CAT database it is estimated that during this earthquake 355,000 people were exposed to intensity VII, of which around 61% were in rural areas.

Aftershocks[edit]

The first mainshock was followed by several aftershocks with magnitudes ranging between 3–4.5 degrees on the Richter scale, reported in the afternoon and evening of 30 May.[2]

On the morning of 31 May 1990 continued the replicas of the two mainshocks. Thus, at 7:48 (local hour) occurred a replica of magnitude 4.7, felt in Bucharest with an intensity of IV degrees on the Mercalli scale. Other replicas of lower magnitudes continued to occur in Vrancea until the end of June 1990, in the depth floor of 70–90 km.[2] Secondary seismic movements, at the same depth, were recorded and later, until October 1990.

Damage[edit]

Economic losses have been reported by Munich Re to be in the region of 30 million US$.[3] In Moldova, the earthquake caused damage to property worth 100 million rubles.[4]

Casualties[edit]

According to data from the General Inspectorate of Police, the earthquake killed nine people. Two of the deaths occurred in Bucharest in the district of Colentina, when the heavy plasterboard of an 11-storey apartment block collapsed along the expansion joint, due to pounding between the two separate parts of the structure.[5] Were injured in total 362 persons, including 100 severely, namely: Bucharest 35, Bacău 14, Brașov 3, Brăila 11, Dolj 1, Galați 12, Ialomița 4, Prahova 14, Vaslui 1, Vrancea 2.[5] Were slightly injured 262 people, of which 103 in Bucharest, 16 in Bacău, 14 in Brașov, 47 in Brăila, 7 in Covasna, 20 in Dolj, 10 in Galați, 8 in Ialomița, 20 in Prahova, 1 in Vrancea.[5] The injuries and deaths were a result of falling chimneys, pieces of construction materials from the upper floors of buildings.[5]

In Moldavia, four people died and dozens were injured,[1] and in northern Bulgaria, one person died of a heart attack.[6]

References[edit]

  1. ^ a b "Significant earthquakes of the world, 1990". U.S. Geological Survey. 
  2. ^ a b c d e "Cutremurele vrâncene din 30 și 31 mai 1990". Cutremur.net (in Romanian). 8 November 2012. 
  3. ^ "Vrancea area Romania 1990 (CAR)". GEM Earthquake Consequences Database. 
  4. ^ Kouteva, M.; Panza, G. F.; Paskaleva, I.; Romanelli, F. (1 May 2004). A view to the intermediate-depth Vrancea earthquake of May 30, 1990 - Case study in NE Bulgaria. Budapest: Akadémiai Kiadó. 
  5. ^ a b c d Andrei Stoicu (31 May 1990). "Radiojurnalul Zilei - 31 mai 1990". Jurnalul Național (in Romanian). 
  6. ^ Alina Neagu (25 April 2009). "Cele mai puternice cutremure din România ultimilor 100 de ani". HotNews.ro (in Romanian).