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Dom João de Castro Bank

Don Joao de Castro Bank

Shield volcano · Portugal · 13m (submarine)

This side-viewing sonar image shows two 45 x 90 m craters on the NW flank of Don Joao de Castro Bank in the Azores taken by U.S. Navy submarine NR-1. The younger left crater displays a floor consisting of a chilled lava lake with polygonal surface fractures. The right crater is much less distinct because its surface is obscured by tephra deposits. The line at the right is the center track line of the sonar image.
This side-viewing sonar image shows two 45 x 90 m craters on the NW flank of Don Joao de Castro Bank in the Azores taken by U.S. Navy submarine NR-1. The younger left crater displays a floor consisting of a chilled lava lake with polygonal surface fractures. The right crater is much less distinct because its surface is obscured by tephra deposits. The line at the right is the center track line of the sonar image. · Photo: U. S. Navy image courtesy of Rick Wunderman, 2003 (Smithsonian Institution).
Type
Shield volcano
Country
Portugal
Region
Atlantic Ocean Volcanic Regions / Azores-Terceira Rift Volcanic Province
Elevation
13m (submarine)
Coordinates
38.230, -26.630
Last eruption
1720
Tectonic setting
Rift zone / Oceanic crust (< 15 km)
Landform
Shield
Major rock type
Basalt / Picro-Basalt
Geological summary

Don Joao de Castro Bank is a large submarine volcano that rises to within 13 m of the ocean surface roughly halfway between Terceira and San Miguel Islands. Pillow lavas form the base of the volcano, which is capped by basaltic hyaloclastites. A submarine eruption during December 1720 produced an ephemeral island that attained a length of 1.5 km and a height of about 250 m before it was eroded beneath the surface two years later. The volcano (also spelled Dom Joao de Castro) was named after the Portuguese hydrographic survey vessel that surveyed the bank in 1941. Two youthful craters, one tephra covered and the other sediment free, are located on the NW flank. The submarine volcano has a shallow fumarole field and remains seismically active.

From Wikipedia

Dom João de Castro Bank is a large submarine volcano located in the central north Atlantic Ocean, between the islands of São Miguel and Terceira in the archipelago of the Azores.

Wikipedia · CC BY-SA · Read full article →

Eruption history

Summary (VEI over time)
Click a bar to see individual eruptions
1720~1748 · 1 eruptions · max VEI 31969~1997 · 1 eruptions · max VEI 017201775185919141969

Detailed timeline

  1. 1997VEI 0Geological estimate
    1997-06-27 – 1997-07-16
    NW of Don Joao de Castro Bank
  2. 1720VEI 3Observed
    1720-12-08 – 1720-12-26

External links

⚠ For reference only. Not for emergency response.