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Ancient Thera - Santorin

The accurate date of the "Minoan" eruption of Santorini is a controversial issue, with estimates running from as early as 1627 BC to as late as 1390 BC. Following the eruption, much of the previous island of Santorini was destroyed or submerged; this event may have been the inspiration for the legend of the "lost continent" of Atlantis. Far from legend however, many archeologists believe that the eruption was a major factor -- or the immediate cause -- of the destruction of the classical Minoan civilization of Crete.

One of the largest volcanic eruptions in the past 10,000 years occurred in approximately 1620 BC on the volcanic island of Santorini in the Aegean Sea, located approximately 118 kilometers to the north of Crete. Prior to 1620 BC, the island of Santorini, now known as Thera, was built up by layers of lava created by overlapping shield volcanoes, and it had experienced three significant eruptions that formed overlapping calderas, or collapsed magma chambers. The fourth (and latest) major eruption created the present-day islands and caldera bay of Santorini Volcano. About 30 cubic kilometers of magma was erupted, forming a plinian column 36 km high. The removal of such a large volume of magma caused the volcano to collapse, producing a caldera. Ash fell over a large area of the eastern Mediterranean.

In 1973 investigators reported that pumice fragments recovered from an archeological excavation on the Greek mainland had been correlated by means of index of refraction measurements with the Late Bronze Age volcanic eruption on the island of Thera (Santorini) in the Aegean Sea. Pottery from the strata containing the pumice dated from the 15th century BC. In 1983 investigators reported that the Minoan eruption sequence of 1390 BC produced a minimum volume of 13 km/sup 3/ of rhyodacitic tephra (dense rock equivalent). The eruptions evolved from magmatic to phreatomagmatic and back to a mix of both processes. Thin section and scanning electron micrograph analysis of the tephra sequence provide information about eruption processes that is critical to interpretation of the field data. The eruptions began at a vent located above sea level and produced a coarse-grained Plinian pumice deposit. All later phases of the eruption involved propagating vent(s) into an older flooded caldera and flooding of the sea into a collapsing Minoan caldera. Interaction of magma and water produced fine-grained tephra that consist mostly of slightly curved, nearly flat shards and small pumice pyroclasts. These were derived during fragmentation of a heterogeneous, vesicular magma containing large compound vesicles and smaller, elongate vesicles. The vesiculated magma was thoroughly comminuted during magma-water interactions. The last eruptive phase is interpreted as having involved both magmatic and phreatomagmatic processes. Hot pyroclastic flows from this phase contained a bimodal mixture of pumice pyroclasts and finely comminuted shards.

In 2006 investigators reported that precise and direct dating of the Minoan eruption of Santorini (Thera) in Greece, a global Bronze Age time marker, had been made possible by the unique find of an olive tree, buried alive in life position by the tephra (pumice and ashes) on Santorini. This team applied so-called radiocarbon wiggle-matching to a carbon-14 sequence of tree-ring segments to constrain the eruption date to the range 1627-1600 BC with 95.4% probability. This result is in the range of previous, less precise, and less direct results of several scientific dating methods, but it is a century earlier than the date derived from traditional Egyptian chronologies.

The island of Santorini, or SantErini, so called from St. Irene, the patroness of the isle, formerly called Thera and Califte, is situate five and twenty leagues north of Crete, being in the form of a crescent, and about thirty five miles in circumference. The island or rock of Therafia is between the two points of the crescent, which together form a large commodiovis harbor. At the bottom of the harbor stands the castle of Scaro or Castro, upon an inaccessible rock, and on each point of the crescent two others.

The physical configuration of Santorini or Thera (the chief of the group), is very remarkable. Its shape is that of a crescent; and is considered to be without a parallel, excepting it he the curiously formed island of Amsterdam in the Indian Ocean. The western or inner shores of Santorini present a series of frightful precipices, from 500 to 1,200 feet in height, in the edges of which are the houses of the inhabitants. The inner shores of the opposite islands, Therasia and Aspronisi, exhibit a similar appearance. The three islands stand in a circular form, and within them rolls the sea over the extinct crater of a vast volcano. Were the crater empty, the head would grow confused as from the heights of Santorini we gazed upon the vast abyss beneath, which is estimated as being at about 2,450 feet deep.

From the ocean crater, then, just alluded to, three mountainous islands rear their heads, the highest of which is about 351 feet above the level of the sea. According to Pliny, in the 4th year of the cxxxv Olympiad, 237 years before the Christian æra, the island of Thera (now Santorini) and Theresia were formed by explosion ; and, 130 years later, the island Hiera (now called the great Kammeni) rose up.

The date of the birth of the first island is doubtful; but that it is the offspring of the ocean crater seems certain. "Between Thera and Therasia," says the ancient geographer Strabo, "flames rose out of the waves for four days, so that the whole sea boiled and blazed, and they gradually threw up an island, just as if it were raised by mechanical means, composed of liquid masses." This island appears to have received additions from volcanic agency at two distinct times, namely, AD 726 and 1457. It is called Paleo Kaimeni, or Old Burnt Island.

The year 1650 arrived, and ominous signs portended another volcanic eruption. Intense drought and unprecedented calms, causing the suspension of the windmills on the island occurred. As the year advanced, the houses rocked to and fro like ships in a tempest. The sea turned green, announcing the fact that metals were in a state of solution; flames rose up out of the water to a height of 18 feet, and were visible at a distance of six miles. "Shortly afterwards there appeared a heap of white earth, like snow, and in the form of a bird's-nest." At length an eruption took place,with a fearful crash; streams of burning matter flowed down resembling liquid fire. The sea roared ; the earth shook ; the air appeared on fire; flames were emitted in torrents from the crater, accompanied with claps of thunder. Large pieces of rock, too, were ejected a distance of six miles. It was nature in its most awful manifestations; a foreshadowing of that solemn season, announced by an inspired pen, when the elements shall melt with fervent heat.

After so terrific an explosion, it well might have been expected that Santorini would have rocked herself to rest. But 110; in May, 1707, two slight shocks of an earthquake betokened that all was not quiet. The fires which water cannot quench were raging beneath; and the month had not passed away, when there appeared floating on the sea what was supposed to be a wreck. In the hope of plunder, a party of seamen rowed towards it, but to their utter astonishment it was a mass of solid rock and white earth! The young island continued to increase, but without noise or violence, till from the size of a mole-hill it had risen to the height of seventy or eighty feet. Shortly afterwards, the sea appeared like oil ready to boil over, and continued bubbling and smoking for about a montb. Jets of flame, resembling so many prodigious sky-rockets, burst in the air. Thunder rolled, clouds of ashes darkened the atmosphere, and fragments of redhot rock flew about, composing a dreadful artillery. At intervals, during some months, these terrible phenomena occurred with more or less violence, and it was not until three years had elapsed that the volcano became entirely tranquil. The new island was then found to have assumed the shape of a cone perfectly white, and three hundred and fifty feet high. It is called New Burnt Island, and forms a useful harbor of refuge.

Santorini consists of a 100,000 year B.P. caldera developed on a group of low volcanoes, and an overlapping around 3,380 years B.P. (perhaps BC 1390) caldera of roughly the same size offset to the north. The younger caldera formed during or shortly after the famous Minoan eruption of 13-19 cubic kilometers (Heiken and McCoy, 1984) or 27 cubic kilometers (Druitt, 1984) of rhyodacite magma. Buildings were apparently destroyed by earthquakes several years or decades before the cataclysmic eruption, and were being rebuilt when they were abandoned (Vitaliano, 1973; Heiken and McCoy, 1984). The islands were abandoned shortly before the cataclysmic eruption, possibly because of small phreatic or phreatomagmatic eruptions that occurred just before the cataclysmic phase of the eruption.

When the Santorini caldera exploded in the Late Bronze Age (ca. 1630 BC), it produced the second largest explosive eruption in historical time (the other being the eruption of Tambora in Indonesia in 1815). This Santorini eruption occurred at a time when the Minoan civilization was dominant in the Aegean Sea, and hence it is generally called the Minoan eruption. Researchers from the University of Rhode Island began studying the products from the Minoan eruption in 1975 by taking sediment core samples of the sea floor between Santorini and Crete, and concluded at that time that the eruption produced at least 39 km³ of magma.

The R/V Aegaeo cruise in 2006 made a great advance on the study of the Minoan eruption by applying seismic air-gun techniques in order to determine the thickness, distribution and volume of the submarine volcanic deposit of pumice and ash on the sea floor around Santorini. Investigators found that a thick pyroclastic deposit, representing pyroclastic flows from the Minoan eruption, can be traced up to 30 km from the volcano and that it ranges in thickness from ten to eighty meters. Its distribution is remarkably similar to the submarine pyroclastic flows from the 1883 eruption of Krakatau in Indonesia – only the Minoan is much bigger. Our results show that the volume of the Minoan deposit on the sea floor is about 41 km³, but to this must be added the distal fallout ash (17 km³), and ignimbrites on the Santorini islands (1.5 km³). Thus the total volume of this important eruption is likely about 60 km³. This much increased volume estimate has important implications for the size of the tsunami waves that may have been generated by the Minoan eruption.

In 2012 investigators reported that exposure to ash from the catastrophic Santorini eruption radically changed Bronze Age medicine, triggering the development of new remedies, the wide dissemination of medical data, and the transfer of technologies. These developments were identified in medical papyri thanks to remedies for ailments linked to volcanic matter an oddity in Egypt, a country without volcanoes. The anomaly was traced back to the Santorini eruption, which through volcanic ash, acidified bodies of waters, and acid rain affected the whole eastern Mediterranean without sparing Egypt. Using available technology, doctors developed new remedies for severe irritation to eyes from ash and for burns on the skin, or imported foreign remedies.

In 2005 one investigator noted that Paragraph 55 of the London Medical Papyrus describes burns derived from red waters and which later became infected with larvae in the wounds. The prescribed treatment for the burn is unusual as it calls for no rinsing and requires bandaging with alkaline materials only. Refraining from washing in the Nile (the single most readily available source of water in ancient Egypt), and the use of alkali-neutralizing agents indicates that the red caustic waters came from the river, and were acid in nature. A red, acid Nile is consistent with the first biblical plague of Egypt, which killed fish, and kept people from drinking from the river. In turn, the sulfate-laced waters of the medical document also offer a plausible insight into the subsequent biblical plagues. Amphibians would have stayed away from the deadly river, left to die on the banks, just as described in the second biblical plague. Similarly, the larvae in the wounds mentioned by the medical document re-echo the third and fourth biblical plagues: the kînnîm invertebrates and the subsequent 'arob (varied insects) are consistent with larvae and the subsequent adults thereof. In pre-industrial Ancient Egypt, sulfates from a massive volcanic fall out provide the simplest and most exhaustive origin for such waters. A massive precipitation that would account for the waters in the medical document and the biblical texts is known from sediments at the bottom of lakes along the Nile Delta. The site is downwind from the island of Santorini, and the deposit of volcanic ashes took place during the Middle Bronze Age, i.e. at a time consistent with the eruption at the Greek volcanic island.

In 2006 one investigator reported that six medical papyri document how Santorini's volcanic ash from the Bronze Age biphasic eruption, otherwise attested by material retrieved at the bottom of lakes at the edge of the Nile Delta, severely affected the health of the inhabitants of Egypt as well as their society as a whole. Treatments for burns caused by particulate and dissolved acids are documented in the London Medical Papyrus as well as in the Ebers Papyrus, and are compatible with ash fallout and ash in rain, respectively.

Furthermore, both instances of ash correlate to the first eight biblical plagues. Moreover, the latter text also presents a series of ailments coherent with serious inhalation of toxic substances in aerosol form. This scenario is confirmed by the Hearst Medical Papyrus, the Carlsberg Papyrus 8, and the Ramesseum Papyrus III, and fits a volcanic plume, which is also coherent with the ninth biblical plague of palpable obscurity as well as Santorini's second phase of its Bronze Age eruption. Finally, a sixth contemporary medical text, the Edwin Smith Surgical Papyrus, a manual to practice on wounded soldiers, supplies an insight into the collapse of the sociopolitical system of the time. The text appears to provide an insight into the sociopolitical climate in the aftermath of the Santorini eruption, possibly describing conditions that would have led to the tenth and final biblical plague of the massacre of firstborn as well as the escape of slaves from local labor camps.