2020-03-09 (IPMA)
Seismology in Madeira
Earthquake | March 7, 2020
On March 7, 2020, at 8:58 pm, an earthquake of magnitude 5.2 occurred, with an epicentral location about 35 km south of the city of Funchal. Based on the information from the seismic network, it was determined that the earthquake had the potential to be felt, and was immediately made an occurrence notification.
According to the information evaluation received from the population, the earthquake was felt practically throughout the island of Madeira and also in Porto Santo, with the maximum intensity (modified Mercalli Scale, 1956) reaching grade V in several locations on Madeira island, namely in the municipalities of Funchal, Câmara de Lobos and Calheta. In Porto Santo the maximum intensity verified was IV (MM56). In this macro-seismic component, the importance of the information received from the population through the completion of the macro-seismic survey made available by the IPMA on its website is highlighted.
The earthquake was recorded at the 5 seismic stations operated by IPMA in the archipelago (see figure), with relatively high levels of ground movement acceleration, particularly in Pico do Areeiro where 35 cm / s2 were measured. The recorded levels of soil movement are compatible with the macrosismic effects reported by the population.
Until 12 o'clock on March 9th, there were 7 replicates, the largest of which was 2.2, the one that occurred at 21:22 on March 7th.
The seismic hazard in the Madeira archipelago is considered inferior to that of the Mainland and that of the Azores, which does not mean that earthquakes cannot occur, some of which have a potentially significant impact. There are records of historical seismic events with significant impact, particularly in 1748 where the maximum intensity will have reached grade VIII (MM56). Also noteworthy are other earthquakes with an impact on the island of Madeira, which occurred in 1816, 1866, 1918, 1923 and 1975. The latter, which occurred on May 31, 1975, had an epicentral location relatively remote from the archipelago, about 350km north of Funchal , but due to the high magnitude, 8.1, the effects on the archipelago were important, with the maximum intensity reaching grade VI (MM56).
In the last 2 years, 80 earthquakes have occurred, generally of low magnitude, with an epicentral location close to the archipelago (see figure).
The seismic information is made available by the IPMA on its website, where, among others, seismic activity is reported, the communications that are prepared in case of earthquakes felt or potentially felt by the population and the list of shakemaps (maps with the forecast are available) geographic distribution of seismic intensity). A macrosismic questionnaire is also available on this website and can be filled out by anyone who has experienced an earthquake.
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