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The 1940 Vrancea earthquake, also known as the 1940 Bucharest earthquake, (Romanian: ''Cutremurul din 1940'') occurred on Sunday, 10 November 1940, in Romania, at 3:39am (local time), when the majority of the population was at home. The 1940 earthquake registered a magnitude of 7.7 on the Richter scale, being the strongest earthquake recorded in the 20th century in Romania. Its epicenter lay in Vrancea zone at a depth of about 133 km. The pleistoseist area of this earthquake was of 80,000 km²〔 and the macroseismic effects were felt on a surface of over 2,000,000 km²,〔 being reported on vast areas, thus: in the north up to Saint Petersburg, at over 1,300 km,〔(【引用サイトリンク】title=Cutremurul din 10 noiembrie 1940 – date sintetice )〕 where there have been estimated seismic intensities of IV–V (MCS degrees), in the south, up to Greece, in the east, up to the Kharkiv–Moscow line, with estimated intensities of V–VI (MCS degrees), in the west, up to Belgrade, Budapest, Warsaw. ==Background== 1940 was characterized by a very high seismic activity in Vrancea.〔(【引用サイトリンク】title=Seismic risk in Romania )〕 In the first months of 1940 there were earthquakes of magnitude 4.5–5 that occurred at depths of 130–160 km. On 24 June, there was an earthquake of magnitude 5.5 at a depth of 115 km, scarcely felt in Wallachia and Moldavia.〔 There followed a period of relative calmness until 3 October, when an earthquake of magnitude 4.7–5.0 occurred at a depth of 150 km.〔(【引用サイトリンク】title=Cutremurul vrâncean din 1940 )〕 On the evening of 21 October, there were many earthquakes, of which the most important took place around midnight at a depth of 100 km (M=4.5). On the morning of 22 October, at 8:37 a.m., a stronger earthquake occurred in Vrancea, of magnitude 6.5 and maximum intensity of VII on the Mercalli intensity scale, at a depth of 122–125 km; this quake was strongly felt, especially in Wallachia and Moldavia. Only light damage, for example, cracks in walls and broken windows, was reported, but no casualties.〔 This earthquake did not have immediate after shocks. At the beginning of November there were, however, several earthquakes over 4.0 at about 140–150 km depth.〔 On 8 November, at 2pm., less than two days before the catastrophic earthquake, there was another earthquake of magnitude 5.5 at a depth of 145 km, which was also felt in Bucharest.〔 A day later, in the afternoon of 9 November there were several weak and local earthquakes, around the town of Panciu, movements which passed almost unnoticed by the population (II–III degrees on the Mercalli intensity scale).〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「1940 Vrancea earthquake」の詳細全文を読む スポンサード リンク
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