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ATLANTIS & the Atlantic Ocean


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Author Topic: ATLANTIS & the Atlantic Ocean  (Read 22109 times)
dhill757
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« Reply #345 on: March 30, 2009, 12:07:03 am »



   Furnas

Furnas volcano, at the eastern end of Sao Miguel Island, contains at least two calderas. The younger 6-km-wide caldera is seen here from its northern rim. At least 11 trachytic pumice layers, all erupted during the past 5000 years, post-date the caldera. A zone of late-Pleistocene to Holocene basaltic-to-trachytic cinder cones and lava domes is located between Furnas and neighboring Agua de Pau volcano. The only historical eruption of Furnas volcano, during 1630, was one of the largest Holocene eruptions in the Azores.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).



 Country: Portugal
Subregion Name: Azores and Madeira
Volcano Number: 1802-10=
Volcano Type: Stratovolcano
Volcano Status: Historical
Last Known Eruption: 1630   
Summit Elevation: 805 m 2,641 feet
Latitude: 37.77°N  37°46'0"N
Longitude: 25.32°W 25°19'0"W
Furnas volcano lies at the eastern end of Sao Miguel Island, immediately west of the older Nordeste shield volcano and its Povoaçao caldera. Furnas contains at least two calderas, a younger one that is 6-km wide and a larger older one that is less topographically distinct. The eastern wall of the 500-m-deep caldera of Furnas overlaps the western wall of the Povoaçao caldera of Nordeste volcano. Volcanic activity at Furnas dates back about 100,000 years. At least 11 trachytic pumice layers, all erupted during the past 5000 years, post-date the caldera. The most prominent post-caldera feature is the Pico do Gaspar lava dome, east of the Lagoa das Furnas caldera lake. A zone of late-Pleistocene to Holocene basaltic-to-trachytic cinder cones and lava domes is located between Furnas and Agua de Pau volcanoes. Two historical eruptions have occurred at Furnas, one sometime between 1439 and 1443 and the other in 1630. The latter was one of the largest Holocene explosive eruptions in the Azores and caused significant damage and fatalities.
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