Geodinâmica e perigosidade natural nas ilhas dos Açores
The central islands of the Azores archipelago exhibit significant volcanic and seismic activity. The most important tectonic structure responsible for this activity seems to be the leaky transform Terceira Rift, a branch of the Azores triple junction separating the Eurasia and Africa plates. In hist...
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ftdoajarticles:oai:doaj.org/article:0bcf764c1d764daaa1577d4960af332d 2023-05-15T16:57:08+02:00 Geodinâmica e perigosidade natural nas ilhas dos Açores António Brum Ferreira 2005-01-01T00:00:00Z https://doi.org/10.18055/Finis1494 https://doaj.org/article/0bcf764c1d764daaa1577d4960af332d EN ES FR PT eng spa fre por CEG https://revistas.rcaap.pt/finisterra/article/view/1494 https://doaj.org/toc/0430-5027 https://doaj.org/toc/2182-2905 doi:10.18055/Finis1494 0430-5027 2182-2905 https://doaj.org/article/0bcf764c1d764daaa1577d4960af332d Finisterra - Revista Portuguesa de Geografia, Vol 40, Iss 79 (2005) Geography. Anthropology. Recreation G article 2005 ftdoajarticles https://doi.org/10.18055/Finis1494 2022-12-31T07:07:47Z The central islands of the Azores archipelago exhibit significant volcanic and seismic activity. The most important tectonic structure responsible for this activity seems to be the leaky transform Terceira Rift, a branch of the Azores triple junction separating the Eurasia and Africa plates. In historical time (since the XV century), the most frequent volcanic eruptions were of the hawaiian and strombolian types, but the level of explosivity has occasionally reached subplinian magnitude, as it happened in the Fogo (1563) and Furnas (1630) volcanoes (hydromagmatic eruptions in the calderas). As in other volcanic regions of the world, effusive volcanism is not particularly dangerous in the Azores islands; explosive activity, however, can be catastrophic (ignimbrites formed in some islands over the last millennia). Still, throughout historical time, earthquakes have been the most dangerous natural phenomena in the Azores, sometimes bringing about tragic consequences: in 1757, an earthquake struck the São Jorge island, killing one thousand people (20% of the total population). But the most catastrophic seismic event of all occurred in the island of São Miguel in 1522: an earthquake triggered an earthflow that submerged the capital (Vila Franca do Campo) and killed nearly all of its inhabitants (several thousands). Whether or not they are triggered by earthquakes, mass movements are most common along the coast of the islands: huge falls and rotational slides are attested for by the so-called fajãs, detrital platforms on the foot of cliffs that are several hundred meters high; in death-defying fashion, some of these platforms are actually inhabitated. Article in Journal/Newspaper Jorge Island Directory of Open Access Journals: DOAJ Articles Fogo ENVELOPE(-54.281,-54.281,49.717,49.717) Jorge Island ENVELOPE(-59.767,-59.767,-62.383,-62.383) Finisterra 40 79 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English Spanish French Portuguese |
topic |
Geography. Anthropology. Recreation G |
spellingShingle |
Geography. Anthropology. Recreation G António Brum Ferreira Geodinâmica e perigosidade natural nas ilhas dos Açores |
topic_facet |
Geography. Anthropology. Recreation G |
description |
The central islands of the Azores archipelago exhibit significant volcanic and seismic activity. The most important tectonic structure responsible for this activity seems to be the leaky transform Terceira Rift, a branch of the Azores triple junction separating the Eurasia and Africa plates. In historical time (since the XV century), the most frequent volcanic eruptions were of the hawaiian and strombolian types, but the level of explosivity has occasionally reached subplinian magnitude, as it happened in the Fogo (1563) and Furnas (1630) volcanoes (hydromagmatic eruptions in the calderas). As in other volcanic regions of the world, effusive volcanism is not particularly dangerous in the Azores islands; explosive activity, however, can be catastrophic (ignimbrites formed in some islands over the last millennia). Still, throughout historical time, earthquakes have been the most dangerous natural phenomena in the Azores, sometimes bringing about tragic consequences: in 1757, an earthquake struck the São Jorge island, killing one thousand people (20% of the total population). But the most catastrophic seismic event of all occurred in the island of São Miguel in 1522: an earthquake triggered an earthflow that submerged the capital (Vila Franca do Campo) and killed nearly all of its inhabitants (several thousands). Whether or not they are triggered by earthquakes, mass movements are most common along the coast of the islands: huge falls and rotational slides are attested for by the so-called fajãs, detrital platforms on the foot of cliffs that are several hundred meters high; in death-defying fashion, some of these platforms are actually inhabitated. |
format |
Article in Journal/Newspaper |
author |
António Brum Ferreira |
author_facet |
António Brum Ferreira |
author_sort |
António Brum Ferreira |
title |
Geodinâmica e perigosidade natural nas ilhas dos Açores |
title_short |
Geodinâmica e perigosidade natural nas ilhas dos Açores |
title_full |
Geodinâmica e perigosidade natural nas ilhas dos Açores |
title_fullStr |
Geodinâmica e perigosidade natural nas ilhas dos Açores |
title_full_unstemmed |
Geodinâmica e perigosidade natural nas ilhas dos Açores |
title_sort |
geodinâmica e perigosidade natural nas ilhas dos açores |
publisher |
CEG |
publishDate |
2005 |
url |
https://doi.org/10.18055/Finis1494 https://doaj.org/article/0bcf764c1d764daaa1577d4960af332d |
long_lat |
ENVELOPE(-54.281,-54.281,49.717,49.717) ENVELOPE(-59.767,-59.767,-62.383,-62.383) |
geographic |
Fogo Jorge Island |
geographic_facet |
Fogo Jorge Island |
genre |
Jorge Island |
genre_facet |
Jorge Island |
op_source |
Finisterra - Revista Portuguesa de Geografia, Vol 40, Iss 79 (2005) |
op_relation |
https://revistas.rcaap.pt/finisterra/article/view/1494 https://doaj.org/toc/0430-5027 https://doaj.org/toc/2182-2905 doi:10.18055/Finis1494 0430-5027 2182-2905 https://doaj.org/article/0bcf764c1d764daaa1577d4960af332d |
op_doi |
https://doi.org/10.18055/Finis1494 |
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Finisterra |
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40 |
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79 |
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