Landslides density map of S. Miguel Island, Azores archipelago
The Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas). Chains of basaltic cinder cones link those major volcan...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2002-01-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/2/51/2002/nhess-2-51-2002.pdf |
| _version_ | 1818525870612021248 |
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| author | P. Valadão J. L. Gaspar G. Queiroz T. Ferreira |
| author_facet | P. Valadão J. L. Gaspar G. Queiroz T. Ferreira |
| author_sort | P. Valadão |
| collection | DOAJ |
| description | The Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas). Chains of basaltic cinder cones link those major volcanic structures. An inactive trachytic central volcano (Povoação) and an old basaltic volcanic complex (Nordeste) comprise the easternmost part of the island. Since the settlement of the island early in the 15<sup>th</sup> century, several destructive landslides triggered by catastrophic rainfall episodes, earthquakes and volcanic eruptions occurred in different areas of S. Miguel. One unique event killed thousands of people in 1522. Houses and bridges were destroyed, roads were cut, communications, water and energy supply systems became frequently disrupted and areas of fertile land were often buried by mud. Based on (1) historical documents, (2) aerial photographs and (3) field observations, landslide sites were plotted on a topographic map, in order to establish a landslide density map for the island. Data obtained showed that landslide hazard is higher on (1) the main central volcanoes where the thickness of unconsolidated pyroclastic deposits is considerable high and (2) the old basaltic volcanic complex, marked by deep gullies developed on thick sequences of lava flows. In these areas, caldera walls, fault scarps, steep valley margins and sea cliffs are potentially hazardous. |
| first_indexed | 2024-12-11T06:15:07Z |
| format | Article |
| id | doaj.art-f20691ebc6c34bde9dad90798f130e02 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-11T06:15:07Z |
| publishDate | 2002-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-f20691ebc6c34bde9dad90798f130e022022-12-22T01:18:00ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812002-01-0121/25156Landslides density map of S. Miguel Island, Azores archipelagoP. ValadãoJ. L. GasparG. QueirozT. FerreiraThe Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas). Chains of basaltic cinder cones link those major volcanic structures. An inactive trachytic central volcano (Povoação) and an old basaltic volcanic complex (Nordeste) comprise the easternmost part of the island. Since the settlement of the island early in the 15<sup>th</sup> century, several destructive landslides triggered by catastrophic rainfall episodes, earthquakes and volcanic eruptions occurred in different areas of S. Miguel. One unique event killed thousands of people in 1522. Houses and bridges were destroyed, roads were cut, communications, water and energy supply systems became frequently disrupted and areas of fertile land were often buried by mud. Based on (1) historical documents, (2) aerial photographs and (3) field observations, landslide sites were plotted on a topographic map, in order to establish a landslide density map for the island. Data obtained showed that landslide hazard is higher on (1) the main central volcanoes where the thickness of unconsolidated pyroclastic deposits is considerable high and (2) the old basaltic volcanic complex, marked by deep gullies developed on thick sequences of lava flows. In these areas, caldera walls, fault scarps, steep valley margins and sea cliffs are potentially hazardous.http://www.nat-hazards-earth-syst-sci.net/2/51/2002/nhess-2-51-2002.pdf |
| spellingShingle | P. Valadão J. L. Gaspar G. Queiroz T. Ferreira Landslides density map of S. Miguel Island, Azores archipelago Natural Hazards and Earth System Sciences |
| title | Landslides density map of S. Miguel Island, Azores archipelago |
| title_full | Landslides density map of S. Miguel Island, Azores archipelago |
| title_fullStr | Landslides density map of S. Miguel Island, Azores archipelago |
| title_full_unstemmed | Landslides density map of S. Miguel Island, Azores archipelago |
| title_short | Landslides density map of S. Miguel Island, Azores archipelago |
| title_sort | landslides density map of s miguel island azores archipelago |
| url | http://www.nat-hazards-earth-syst-sci.net/2/51/2002/nhess-2-51-2002.pdf |
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