[escepticos] Sobre lo de Thera (sólo leer fanaticos del tema)

[borgonoz@...>]

Esta fuera del tema, pero lo pongo porque se habló de la cuestión hace algún
tiempo.

Son dos nuevas publicaciones sobre lo de Thera, con sus resumenes (todo en
inglés). Una de ellas, la segunda, es la de Antiquity que yo ya había citado.

En fin, espero que satisfaga la curiosidad de alguien,

Alfonso

PD.: Por cierto, arqueólogos, es posible que vaya a Cartagena al Congreso
nacional de Arqueología. Si va alguien, que me diga algo en el correo privado.

NEW PAPERS ON BRONZE AGE CATASTROPHES 


(1) M. B. Cita & B. Rimoldi: Geological and geophysical evidence for a 
Holocene tsunami deposit in the eastern Mediterranean deep-sea 
record. 

(2) P. C. Buckland, A. J. Dugmore & K. J. Edwards: Bronze Age 
myths? Volcanic activity and human response in the Mediterranean 
and North Atlantic regions. 

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M. B. Cita & B. Rimoldi: Geological and geophysical evidence for a 
Holocene tsunami deposit in the eastern Mediterranean deep-sea 
record. JOURNAL OF GEODYNAMICS, 1997, Vol.24, No.1-4, pp.293-304
 
Extended geological and geophysical exploration of basinal settings 
in different areas of the eastern Mediterranean demonstrate the 
existence of a Holocene mud layer several metres in thickness (up 
to more than 20 m) and typically showing a graded basal part. The 
event producing this peculiar deposit is correlated with the 
gigantic 'Bronze Age' or Minoan eruption of the Santorini volcano 
(3500 years BP), which resulted in caldera collapse and supposedly 
produced a strong seismic sea-wave, that is a tsunami. Order of 
magnitude calculations demonstrate that the wave speed was 
sufficient to induce erosion and liquefaction of the soft 
unconsolidated sediments draping the deep-sea floor. The event is 
recorded in over 50 deep-sea cores recovered in the last 20 years 
which contain the fine grained 'Homogenite' layer  starting with a 
fining-upwards sandy base and having a thickness of more than 24 m 
in the Sirte Abyssal Plain area. Several depositional models 
related to setting and source areas and based on thickness, 
composition, carbonate content and sedimentary structures of the 
deposits have been proposed. 
 
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P. C. Buckland, A. J. Dugmore & K. J. Edwards: Bronze Age myths? 
Volcanic activity and human response in the Mediterranean and 
North Atlantic regions. In: ANTIQUITY 273 (1997), pp. 88-105 
  
A first rule of statistics is that the existence of a correlation 
does not itself prove a causal connection. This is the heart of 
the recurrent question in later European prehistory whether in the 
Mediterranean or in the Atlantic northwest about volcanic 
eruptions, their impact on climate, and then of the climatic 
impact on human populations. The burial under tephra of the Late 
Bronze Age settlement of Santorini is proof of a particular 
catastrophe: but is there the evidence to prove wider European 
calamity?
  
A search for precision beyond that currently available is a frequent 
aspect of archaeological interpretation. Tensions exist as a 
result of the need to resolve events on a human time-scale using 
techniques often incapable of producing such accuracy or 
precision. Dendrochronology, ice-core analysis and 
tephrochronology, where data-resolution can be constrained either 
by annual to sub-annual banding or precise isochrones, can make 
important contributions to tackling the persistent chronological 
problems in archaeology. In these interdisciplinary transfers 
there is always the danger that the necessary caution about the 
ways in which the data are used may be lost. This problem is 
particularly acute when the events being studied are real, or 
imagined catastrophes (cf.. White & Humphreys 1994). Catastrophes 
be they the destruction of Bronze Age Thera, the modern island of 
Santorini in the Aegean, or the apparent collapse of Middle Bronze 
Age settlement in upland Britain are headline news; of such things 
myths and reputations are born and enter the literature as if 
proven fact. This paper examines some of the available evidence 
for these two Bronze Age 'catastrophes', the one real and in need 
of a calendar date, the other hypothesized on archaeological 
grounds and dated by a tenuous link through tree rings to an 
Icelandic volcano. Since Marinatos (1939) connected a major 
eruption on Santorini, which destroyed the extensive Late Bronze 
Age town at Akrotiri, with the end of Minoan Crete, the date of 
this eruption has generated more discussion and controversy than 
perhaps any other cataclysmic event in prehistory. Initial 
archaeological considerations favoured a date close to c. 1500 BC 
(Renfrew 1990a), whilst later, calibrated radiocarbon dates tended 
towards the 17th century BC (Kuniholm 1990). In 1977, Hammer noted 
a correlation between acidity, measured by electrical conductivity 
in the Crête ice core from central Greenland, and the timing of 
volcanic events on a world scale. It was further suggested that 
one particular acidity peak lay sufficiently close to the 
archaeological evidence for the date of the eruption to be that 
generated by Santorini (Hammer et al. 1980). By the counting of 
annual layers of ice accumulation in the core, this provided a 
date of 1390±50 BC. On the additional evidence of the Dye 3 core 
from southern Greenland, this was subsequently revised to 1645±7 
BC (Hammer et al. 1987). LaMarche & Hirschboeck (1984), working on 
tree rings from the American Southwest, had noted 'frost rings' 
(lines of severely retarded growth) which they associated with 
unseasonally cold conditions and correlated with major eruptions; 
on this basis, they suggested a date of 1628­1626 BC for the 
Santorini eruption. This was taken up by researchers at the 
Queen's University Palaeoecology Centre in Belfast, who sought 
volcanic impact in the extended oak chronology from Ireland. 
Baillie & Munro (1988) located a particularly narrow series of 
rings beginning in 1628 BC; influenced by Lamb's (1970) discussion 
of the impact of volcanoes on climate, they equated these with a 
stratospheric dust veil from Santorini. Despite several cautionary 
comments from both archaeologists (Manning 1988; Warren 1988) and 
geologists (Pyle 1989; 1990), the 1628 BC date, or one close to 
it, continues to be accepted (e.g. Michael & Betancourt 1988), 
without questioning why the effects of the Santorini eruption 
should be especially recognizable in the ice-core and tree-ring 
sequences. Large-scale explosive volcanic activity is common on a 
global scale (Zielinski et al. 1996), and so before accepting the 
possibility that the Santorini eruption can be recognized by 
unusual perturbations in the regional records of ice-cores or 
tree-rings, the case for its distinctive character must be proved. 
Despite the lack of critical assessment of these basic 
assumptions, Renfrew (1990b), in his summing up to the Third 
International Congress on Santorini in 1988, went so far as to 
suggest that, by the time of the next Congress, the date of 
the eruption would be unequivocally known to within one year. If 
the Aegean and Anatolian tree ring sequences (cf. Kuniholm 1995; 
Kuniholm et al. 1996) can be tied in from trees lying directly in 
the paths of the fall-out cloud, this may well be the case. The 
correlations from California to Greenland, Ireland and the Aegean, 
however, rely upon suppositions which find questionable support in 
the basic scientific evidence.