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The 1901 Black Sea earthquake (also known in Bulgaria as Balchik earthquake) was a 7.2 magnitude earthquake,〔("Some geoindications of recent geological activity along the northern Bulgarian coast" ), ''Lithuanian Geological Survey''〕 the most powerful earthquake ever recorded in the Black Sea.〔("S-a cutremurat Marea Neagră" ), ''Jurnalul.ro'', August 5, 2009〕 The earthquake epicenter was located in the east of Cape Shabla-Kaliakra, 30 km off northwest coast of Bulgaria. The mainshock occurred at a depth of 15 km and generated a 4–5 m high tsunami that devastated the coastal areas of Romania and Bulgaria. In Romania, the earthquake was felt not only throughout Dobrogea, but also in Oltenia and Muntenia, and even in southern Moldova. The earthquake was followed by a large number of local replicas and secondary earthquakes, which occurred over many years, until 1905; the strongest aftershocks reached magnitudes of 5.5-6.0 on the Richter scale and were also felt in southern Romania, including Bucharest. After 1905, Pontic seismic activity began to subside, although weak and moderate earthquakes were also reported in subsequent years. Such events are rare in the Black Sea. In the last 200 years, in the Black Sea region 24 tsunamis occurred, of which two were in the territory of Dobrogea. The earliest recorded tsunami in Romania dates from 104, when the city of Callatis, current Mangalia, was badly affected. == Background == The off-shore region of Southern Dobruja, especially the epicentral area located in the south of Mangalia, including the Bulgarian off-shore of the Black Sea, has been emphasized over the years, by earthquakes which in certain cases have been violent, reaching magnitudes of 7–7.5 on Richter scale. These are also crustal earthquakes, of low depth (5–30 km), with severe effects on the epicentral area. Sometimes, in case of earthquakes with underwater focus (as those located in the east of Shabla Cape), tsunami waves were generated, like in 1901. Research studies carried out by experts have shown that Pontic earthquakes with destructive behaviour, comparable to that in 1901, repeat at mean periods of 300–500 years. One of the earliest occurred in the 1st century BC at Kavarna. In AD 853, a tsunami at Varna swept 6.5 km inland over flat coastal plain and travelled 30 km up a river.〔("Seismic risk in Romania" ), ''Bauhaus-University Weimar''〕 The Black Sea is considered one of the most violent seas due to its seismic activity.〔 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「1901 Black Sea earthquake」の詳細全文を読む スポンサード リンク
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