Tree Ring and C14 Dating
"The third Thera Conference [Athens 1990] turned into a battleground between archaeology and the newer disciplines of dendrochronology and radiocarbon (C14) dating. Findings from these fields were thrown into the ring, and their supporters argued strongly that the eruption was to be dated more than a hundred years earlier to 1628/7 B.C.
"In several locations of the western United States lives the oldest known living thing on Earth: this is the Bristlecone pine (Pinus longaeva). In one location at Campito Mountain in the White Mountains of California, living trees and deadwood pieces provide an accurate year-by-year tree ring sequence back to 3435 BC, a continuous record for five and one-half thousand years!
"The California bristlecones record only two other frost-ring events during the first three millennia B.C., and both are easily identifiable in ocean sediments. The first freeze seems to be linked with the 1900 B.C. explosion of Mount St. Helens, only a few hundred miles north of the trees. The second front-ring event follows, by a year or less, the 44 B.C. eruption of Mount Etna, and also coincides with an acid signature in Greenland ice dating to about 50 B.C. (give or take twenty years)."
"New data about climatically-effective volcanic eruptions during the past several thousand years may be contained in frost-damage zones in the annual rings of [pine] trees. There is good agreement in the timing of frost events and recent eruptions, and the damage can be plausibly linked to climatic effects of stratospheric aerosol veils on hemispheric and global scales. The cataclysmic proto-historic eruption of Santorini (Thera), in the Aegean, is tentatively dated to 1628-26 BC from frost-ring evidence."
The suggestion the suggestion that the massive emission of ash from the Thera eruption was a possible cause in a global lowering of temperature was "was taken up by Dr Baillie in Belfast, who looked at his records for Irish (bog) oaks, and found a 'narrowest ring event' starting in 1628 B.C. Bailie has argued strongly that there is a causal relationship with Thera, and that the eruption provides a unique solution for the frost damage." Further confirmation comes from the Greenland ice cap. Trace amounts of sulfur have been found in a layer which has been dated to the same period.
University of Copenhagen glaciologist Claus Hammer "acknowledges that ice-layer dates cannot be counted back as easily or precisely as Californian bristlecone rings. Keeping this limitation in mind, he places the acid snow at 1644 B.C., give or take twenty years."
(2) Calibrated Radio-Carbon Dating
"From Thera itself came carbonized tree trunk, still rooted in Minoan soil at the bottom of the Fira quarry."
"C-14 dates for short-lived materials from the Theran eruption span the period 1760-1540 BC with the great majority falling earlier in that period. As a result, in 1989 the Third International Thera Congress favored an eruption date between circa 1680 and 1670 BC."
"Some Minoan experts, Philip Betancourt for instance, are prepared to accept the alternative 'high' dating for the eruption. Their willingness to do so is influenced by another line of evidence, that of radio-carbon (C14) dating. I have so far shrunk from deploying this subject because of its extreme complexity. At the time of the third Conference it did seem that on balance C14 dates derived from organic materials from the Akrotiri site favoured the higher dating. But there are many complicating factors, and the case is still being argued by the experts. There appear to be problems about sample contamination, and re-runs of tests on the same material sometimes produce different results. There are also fundamental problems about the recalibration curve and margins of error. It is possible that the C14 method may never be sufficiently precise to settle the issue. Archaeologists, like Peter Warren, who stick to the lower dating, can quote a modicum of dates that favour their side, and for the time being suspension of judgement seems the safest course."
"Oceanographer Daniel Stanley...and Harrison Cheng, both of the Smithsonian Institution, discovered a Nile Delta ash layer and have identified its chemical fingerprint as an exact match with ash from Thera....There is dead organic matter in the mud upon which the layer fell, and in the mud that was later deposited on top of it."
"In the late 1970's when C-14 dates were corrected by use of the bristlecone pine calibration curves, a 'problem' soon became apparent for the third millennium BC and earlier times. In 1976, R. D. Long looked at the published radiocarbon dates and found them generally older than the historical chronology." "What is much less well known is that the C-14 problem also affects Egypt's 18th Dynasty. We have towards the end of this dynasty a set of calibrated radiocarbon dates from Tell el-Amarna which tie in acceptably well with the conventional chronology. On the other hand, at the beginning of the dynasty we have the eruption of Thera, whose ash straddles the Late Minoan IA period (in Aegean archaeology terms). For many years archaeologists had tied LM 1A into the early 18th Dynasty on the basis of their ceramic chronology. This dated the eruption to the reign of Ahmose [1552-1527 B.C.E.] or later. The date for the eruption, established by archaeologists, has recently received dramatic confirmation in M. Bietak's discovery of pumice within a stratified context at Tell ed-Daba (Ezbet Helmi) which spans the period from Ahmose to Thutmose III (1539-1425 BC)." [According the Rohl's New Chronology, the period from Ahmose to Thutmose III spanned 1194 to 1085 B.C.E.]
"In the conventional chronology, the earliest Ahmose could have reigned according to Egyptian dating is circa 1550 BC which is at least 120 years later than the date of the eruption established by the radiocarbon method....Clearly it would be inconsistent to use C-14 to fix an absolute date for just one end of this dynasty: it is therefore an 'all or nothing situation' in which radiocarbon dating has to be embraced (with all its consequences) or rejected - even where the dates it yields seem to agree with the chronology."
(3) Confirmation from Historical Records Support for placing the eruption of Thera in the seventeenth century B.C.E. comes from an ancient Chinese text referring to the time of King Chieh. "King Chieh lived at the same time as T'ang (the first king of the Shang Dynasty), which, according to scribes, was sixteen generations before King Wen. Because the Chinese considered a generation to be thirty years long, one can infer that Chieh ruled about 480 years before Wen - around 1617 B.C., plus or minus a decade or two. Armed with additional eclipse dates for 1876 B.C. (twenty-five generations before Wen) and 1302 B.C. (five generations before Wen), Kevin Pang plotted the eclipses on a graph, fitting a curve through them and locating the point that, according to Chinese history, places Chieh sixteen generations before Wen."
"We find the date is again 1600 B.C., plus or minus thirty years. Thus the historical records confirm what was suggested by the ice cores, tree rings and older radiocarbon dates - that Thera [exploded] late in the seventeenth century B.C."
"After the appearance of LM1B pottery and the partial rebuilding of the palace at Knossos, one administrator or another built himself a tomb on the outskirts of the capital. When he died, the tomb was filled with objects from his life, including clay tablets covered with the early Greek Linear B script, examples of marine-style pottery and an alabaster vessel imported from Egypt and inscribed with the name of Tuthmosis III, who ruled for a time in a coregency with Queen Hatshepsut, history's first woman pharaoh."
"Amenophis II, who ruled from about 1600 B.C. [according to the conventional chronology], is the last pharaoh whose tomb hieroglyphs make reference to Keftiu [generally accepted as Minoan Crete]. On the walls are paintings of foreigners bearing Minoan objects. The Karnak tomb of Rekhmire, vizier to Tuthmosis III (who ruled during the fifty years preceding Amenophis II, and has long been regarded by biblical scholars as a pharaoh who oppressed Moses' people), also bears written references to Keftiu, beneath paintings of men carrying typically Minoan bowls and rhytons [LM1A style and one LM1B] (fragments of which were actually found buried in the tomb). But their hairstyles do not resemble the locks and half-shaven heads depicted on many Minoan frescos, and their kilts, which were originally painted to show Minoan styles, were painted over again to show a longer, more ornate style characteristic of early mainland Greece. The repainting seems to reflect Egyptian awareness of a shift of power in the Western sea."
"The Egyptians in the mid-2nd millennium, knew that the Keftui came from Crete but later the name, like Kaptara [of Syrian writings], seems to have broadened its meaning to that of Aegean lands in general, or even parts of the Anatolian coast."
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