Kolumbo (volcano)
Encyclopedia
Kolumbo is an active submarine volcano
in the Aegean Sea
, about 8 km northeast of Cape Kolumbo, Santorini
island. The largest of a line of about twenty submarine volcanic cones extending to the northeast from Santorini, it is about 3 km in diameter with a crater 1.5 km across. It was "discovered" when it breached the sea surface in 1649-50, but its explosion was not to be compared to the well-known Thera explosion and caldera
collapse, currently dated ca. 1630 BCE, with its devastating consequences for Minoan civilization
. The Smithsonian Institution's Glabal Volcanism Program treats it as part of the Santorini volcano.
The 1650 explosion, which occurred when the accumulating cone reached the surface, sent pyroclastic flow
s across the sea surface to the shores and slopes of Santorini, where about seventy people and many animals died. A small ring of white pumice
that formed was rapidly eroded away by wave action. The volcano collapsed into its caldera
, triggering a tsunami
that caused damage on nearby islands up to 150 km distant. The highest parts of the crater rim are now about 10 m below sea level.
In 2006, sea floor pyroclastic deposit
s from the two Aegean explosions were explored, sampled and mapped by an expedition by NOAA Ocean Explorer, equipped with ROV
robotics.
The crater floor, averaging about 505 m below the sea surface, is marked in its northeast area by a field of hydrothermal vent
s and covered by a thick bacterial
community, the 2006 NOAA expedition discovered. Superheated (measured as hot as 224°C) metal-enriched water issuing from the vents has built chimneys of polymetallic sulfide/sulfates to a maximum height of 4 m, apparently accumulated since the 1650 event.
The 2006 expedition initiated new seismic air-gun techniques in order to determine the volume and distribution of the submarine volcanic deposit of pumice and ash on the sea floor around Santorini, which has been studied extensively since 1975. Revised, more accurate estimates of the total dense rock equivalent volume of the Minoan event(s), consisting of pyroclastic sea floor deposits, distal ash fallout and ignimbrite
s on the island of Santorini, is likely about 60 km³, a greatly increased estimate, comparable to the largest historic explosion, Mount Tambora
1815; the increased estimate affects the size of the ensuing tsunami
as it has been widely modeled.
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
in the Aegean Sea
Aegean Sea
The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...
, about 8 km northeast of Cape Kolumbo, Santorini
Santorini
Santorini , officially Thira , is an island located in the southern Aegean Sea, about southeast from Greece's mainland. It is the largest island of a small, circular archipelago which bears the same name and is the remnant of a volcanic caldera...
island. The largest of a line of about twenty submarine volcanic cones extending to the northeast from Santorini, it is about 3 km in diameter with a crater 1.5 km across. It was "discovered" when it breached the sea surface in 1649-50, but its explosion was not to be compared to the well-known Thera explosion and caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
collapse, currently dated ca. 1630 BCE, with its devastating consequences for Minoan civilization
Minoan civilization
The Minoan civilization was a Bronze Age civilization that arose on the island of Crete and flourished from approximately the 27th century BC to the 15th century BC. It was rediscovered at the beginning of the 20th century through the work of the British archaeologist Arthur Evans...
. The Smithsonian Institution's Glabal Volcanism Program treats it as part of the Santorini volcano.
The 1650 explosion, which occurred when the accumulating cone reached the surface, sent pyroclastic flow
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
s across the sea surface to the shores and slopes of Santorini, where about seventy people and many animals died. A small ring of white pumice
Pumice
Pumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid...
that formed was rapidly eroded away by wave action. The volcano collapsed into its caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
, triggering a tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
that caused damage on nearby islands up to 150 km distant. The highest parts of the crater rim are now about 10 m below sea level.
In 2006, sea floor pyroclastic deposit
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
s from the two Aegean explosions were explored, sampled and mapped by an expedition by NOAA Ocean Explorer, equipped with ROV
Rov
Rov is a Talmudic concept which means the majority.It is based on the passage in Exodus 23;2: "after the majority to wrest" , which in Rabbinic interpretation means, that you shall accept things as the majority....
robotics.
The crater floor, averaging about 505 m below the sea surface, is marked in its northeast area by a field of hydrothermal vent
Hydrothermal vent
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both...
s and covered by a thick bacterial
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...
community, the 2006 NOAA expedition discovered. Superheated (measured as hot as 224°C) metal-enriched water issuing from the vents has built chimneys of polymetallic sulfide/sulfates to a maximum height of 4 m, apparently accumulated since the 1650 event.
The 2006 expedition initiated new seismic air-gun techniques in order to determine the volume and distribution of the submarine volcanic deposit of pumice and ash on the sea floor around Santorini, which has been studied extensively since 1975. Revised, more accurate estimates of the total dense rock equivalent volume of the Minoan event(s), consisting of pyroclastic sea floor deposits, distal ash fallout and ignimbrite
Ignimbrite
An ignimbrite is the deposit of a pyroclastic density current, or pyroclastic flow, a hot suspension of particles and gases that flows rapidly from a volcano, driven by a greater density than the surrounding atmosphere....
s on the island of Santorini, is likely about 60 km³, a greatly increased estimate, comparable to the largest historic explosion, Mount Tambora
Mount Tambora
Mount Tambora is an active stratovolcano, also known as a composite volcano, on the island of Sumbawa, Indonesia. Sumbawa is flanked both to the north and south by oceanic crust, and Tambora was formed by the active subduction zone beneath it. This raised Mount Tambora as high as , making it...
1815; the increased estimate affects the size of the ensuing tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
as it has been widely modeled.
Further reading
- Vougioukalakis, G., A. Sbrana and D. Mitropoulos, 1995. "The 1649-50 Kolumbo submarine volcano activity, Santorini, Greece," in F. Barberi, R. Casale, M. Fratta, (eds.) The European Laboratory Volcanoes: Workshop Proceeding (Luxembourg: EC European Science Commission) pp 189-92.