geological factors part in the minoan society vulnerability...

25

The Mediterranean World Environnement and History

© 2003 Elsevier SAS. Tous droits réservés

Geological factors part in the Minoan societyvulnerability process (Crete-Greece)

G. Poursoulis

1. Introduction

The part of the geological factors in the Minoansociety’s vulnerability process is one subject of mymulti-disciplinary research project. From a long timeI am interested by the Minoan society’s evolutionthrough the question of the minoan palacesdestruction. The results I obtained until now inanalysing the Cretish seismicity, the architecturalremains of numerous archaeological sites and thehuman comportment in seismic areas led me to thinkthat the historical complex situation I found in Creteduring the Bronze Age, was connected with theevolution of the Minoan society, generated by humanactions more than by natural phenomena. It appearsthat, at a particular moment of its history, the minoansociety, until then prosperous on the national scaleand influencial on the international one, supportedsuch a weakening that it offered to the Mycenaeans thepossibility to supersede the Minoans inside Crete, bytaking the political power, as well as on the scale ofeconomical exchanges with all the Méditeranean area.

So, to understand the reasons of this weakening, wemust take into account all the different factors thathad able to play a part in the process, which had putthe Minoan society in a vulnerable state. Generally, ahistorical situation was more the result of numerouscombination of circumstances, than the effect of aunique factor. Among all the factors we couldconsider, geological events represent the first stage ofour research.

2. Presentation of the historical situation

The historical data concerning various Minoan siteslike palaces as well as private houses on the wholeCretish territory (Poursoulis, 1999) and theinterpretations of the economical Linear B whritings(Bennet, 1985, 1990; Duhoux, 1976; Duhoux andMorpurgo-Davis, 1985) found in Knossos and also onthe Greek sites like Mycenae, Pylos and so on, led meto consider that changes happened in the Minoansociety. The result of these changes was a completecentralisation of the economical and political powersin a unique palatial structure: that of Knossos afterdestruction of the three other palaces found until now(

Table 1

).Effectively, the continuous economical expansion of

the Minoan society as well as the regular increase ofpopulation, visible by the step up of settlements on thewhole island from 3000 to 1500 BC (

Fig. 1a,b

),combined with an important developement ofexternal exchanges at this same date, involved that itprobably became necessary to manage more narrowlythe agricultural and artisanal productions, firstly forthe satisfaction of the internal consummation needs incontinuous augmentation and secondly to answer tothe external demand also in continuous increase

The result of this situation visibly was a completecentralisation of the economical and political powers,which led to put out of use the three palaces of Malia,Phaistos and Zakros and let the palace of Knossosmanaging alone the economy of the whole island. Thisultra-centralised system which seems to had workeduntil 1300 BC results however with the hold of powerby the Mycenaeans at this date and further to thedecline of the Minoan civilisation.

The Mediterranean Instability from Yesterday to Today/L’instabilité méditerranéenne d’hier à aujourd’hui

26

Table 1

Chronological table for Bronze Age period in Crete

Dates (BC) Phases Important events for the most known sites

7000–6500 Neolithic Aceramic First settings at Knossos

6500–5700 Old Neolithic First occupation at Palaikastro and Phaestos, numerous settlements in caves at Epano ArchanesFirst occupation in west Crete, especially in caves around Chania

5700–4700 Middle Neolithic

4700–3250 Last Neolithic First occupation on Lassithi plain

3250–2500 Old Minoan I First occupation at Kato Zakros, Gournia

2500–2300 Old Minoan II First occupation at Myrtos Pyrgos and Phournou Korifi

2300–2100 Old Minoan III First occupation at Malia, Vassiliki and Tylissos

2100–1900 Middle Minoan IA

Beginning of exchanges with the east Mediterranean areaConstruction of the palaces at Phaestos, Malia and Knossos

Multiplication of settlements on the whole island of Crete.

1900–1800 Middle Minoan IB

1800–1700 Middle Minoan II

1630–1628 Date of Thera’s eruption after the physico-chemical analyses

1700–1600 Middle Minoan III

Transformation of the palatial and some ordinary buildings

to use the new symmetrical plan divided in dynamic, seismo-resistant blocs.

Construction of the palace at Kato Zakros; Linear A script used at Knossos

1600–1500 Last Minoan IA Transformations in the palace of Kato Zakros

1500 Date of Thera’s eruption after the pottery found at Akrotiri

1500–1450 Last Minoan IB Around 1450 BC, the three palaces of Malia, Phaestos and Zakros are set on fire and abandoned

The occupation of Crete was at its highest level around 1500 BC

Multiplication of the settlements on the whole occupied sites, with an important concentration around Knossos

1450–1400 Last Minoan II Phase very strongly associated with the LMIB period and could constitute only one phase with it

1400– 1350 Last Minoan IIIA1 Burning of the east part of “Maison E” at Malia

1350– 1300 Last Minoan IIIA2

Appearance of the Linear B script on mud shelves, burning at Knossos

Geological factors part in the Minoan society vulnerability process (Crete-Greece)

27

The date of Mycenaeans intervention in Crete isdiscussed by the specialists of Minoan archaeology. Thisdate is estimated on the base of Linear B tablets one,tablets found in the palace of Knossos and transcribingMycenaean Greek. Some archaeologists want to considerthese tablets contemporaneous with the palacesdestruction localised in 1450 BC and by this way renderthe Mycenaeans responsible for these destructions. Otherarchaeologists on the contrary (Palmer, 1969, p. 34;Popham, 1970) gave these tablets a latest date, near1300–1250 BC, based on their analysis on the shapes anddecorations of ceramics found in the last state of Knossospalace, the same one in which were found the tablets.

My analysis of numerous Minoan settlementsevolution on the whole Cretish territory led me to

consider that the Mycenaeans intervention wouldrather be situated near 1300 BC. Several argumentscame to support this assumption.

2.1. The decreased number of occupied settlements

The war conflicts, generally, let remarkable traces in theterritory’s occupation. An important decrease of theoccupied settlements number could be a sign of conflict.It could represent an increase in mortality, resulting tothe battles, but also to the starvations generated by theimpossibility to produce sufficent quantities of thefoodstuffs necessary to the day needs of the population.

1300–1200 Last Minoan IIIB Some badly constructed walls are located at Phaestos. Plan of Mycenaean type at Malia Palace’s North Court locationBad constructions on the east part of the “Maison E” at MaliaDecrease of the occupied settlements on the whole territory, except at Epano Archanes where the occupation continues. The occupation continues in the east part of the palace of Knossos, after the burning and the appearance of the Mycenaeans in Crete

1200–1050 Last Minoen IIIC Period of crisis, collapse of occupation, Knossos continues; but it is the end of its powerAppearance of a first cremation at Malia in “Maison E” (foreign element of Mycenaean origin)

[New Dates after “The Aegean Civilisations” by R. Treuil et al. (1989), in P.U.F. Nouvelle Clio (Éd.)].

Table 1

Chronological table for Bronze Age period in Crete

Dates (BC) Phases Important events for the most known sites

Fig. 1.

Plan of occupation in Crete.

Fig. 1a.

Presenting a general proposition for settlements organisation around the palatial centers (by the author, to bepublished in the 9th International Congress of Cretan Studies Elounda Crete october 2001).

H (habitat)T (tombes)C (cimetière)S (sanctuaire)O (objets)Gt (tombes en grotte)Gh (habitat en grotte)Go (objets en grotte)Gs (sanctuaire en grotte)

MRI

Chamaitoulo

Sitia

Itanos.Vai

Palaikastro

Petsopha

Kato Zakros

Azokeramos

.Traostalos

Xerokambos

Kavallous

Agia Photia

PiskokephaloKato Episkopi

Zou

SphakiaMaronia

Epano EpiskopiPraisos

ZirosEtia

Mesa Apidi

Achladia

Skopi

Riza

.ChamaiziExo Mouliana

M. Mouliana

MyrsiniTourloti

SphakaLastro

Kavousi

Makrygialos

A. StéphanosStavrochori Pevkoi

Tourtouloi

Modi

Epano Zakros

Kalo Chorio

Mochlos

Pseira

Pachyammos

VassilikiGournia

Episkopi

Pyrgos

Kalo Chorio

Myrtos/PyrgosMyrtos/Phournou

Kalamafka

Kritsa

Katharo

Agios Nikolaos

Elounda

Myronikitas

Phouni

Choumeriakos

Vrachasi

Sissi

Malia

Mochos

KrasiKera

PinakianoTzermiado

Kalami

Messa lassithiA. Kostandinos

A. GeorgiosAvrakontes

Kaminaki

M. Kroustallenia

Psychro

PlatiA. Charalambos

Kato MetochiM. Vidiani

Chersonissos

Kalo ChorioKoxari

SkotinoGouvès

Smari

KastelliApostoloi

SambaZophori

Arvi

Kato SymiPevkos

Amiras

A. VassiliosKeratos

Ano ViannosKato Viannos

Chondros

Kephali Chondrou

Nipiditos

Mathia

Avli

Kokkini Chani

AnopoliK. Vatheia

A. IoannisE. Vatheia

Elaia

Itanos/Eileithia

Amnissos

Keratokambos

Tsoutsouros

Héraklion

KnossosGournès

Gazi

Giophyrakia

Athanatoi

Phoinikia

StavrakiaVoutès

A. Myronas

YouktasE. Archanès

Kounavoi

VathypetroA. Paraskiès

Choudetsi A. ParaskeviAstritsi Voni

ArkalochoriZindaPartheni

M. EpanosifiDamania

Arkadi

Tepheli

Ligortynos

Néochori

Kanli Kastelli

Moria

Rotasi

DorakiPanagia

Kapetania

KyparissosPyrgosSiva

KavrochoriTylissos

Moni

Prasan

EpiskopiAïtania

Choumeri

SklavokamposGoniès

A. Pelagia

Achladia

Marathos

Vassilika AnogiaApesokari

Gortyne

Mitropoli

Levin

Krotos

A. Kyrillos

Kaloi Limenès

M. Odigitria

Kalamaki

KommosPitsidia

SivasKousès

AlithiniPombia

Kamilari

A. Triada PhaistosPetokephali

XeniakosKasanos

Voritsi

Galia

Klima Kalochorafitis

GergeriSata

Kamarès

Ideon Andron

Anogia

Axos

Choumeri

PeramaAgelliana

Viran EpiskopiPlatanièsRethymnon Chamalevri

Prasiès

MesiPigi

MyrthiosSelliArmeni

Koumi

A. Antonios Veni Monastiri

ChalaraPatsos

Thronos/SybritaVistagi

Meronas

Messonisia ElenèsAmari Monastiraki

Ano Meros

Vizari

A. IoannosApodoulou

Saktouria

Dramia

Drapanos

Sphakia

Kokkino Chorio

GavalochoriStylos

Samonas

Melidoni

Chania

Platyvola

Nerokouros

Varypetro

Perivolia

Debla

KoumarèsA. Ioannis

ChordakiKambani

A. Triada

A. MarinaMaleme

ModiVrysès

Aphrata

Néa Roumata

Topolia

Platanos

Kalyviani

Gramvousa

A. Onouphrios

Axenti

Stavros

Drapania

Therisos

Pigi

Rizikas

Gangalès

Pigaïdakia

Zaros

Kalamas

Melidoni

AdeleMaroulas

Mixorouma

Pyrgos

Myloniana

Skourachlada

Asphardon

Galatas

Chalepa M. Arsani

Kouphonisi

Chandra

Plati

DorièsKoudoumalia

Marmaketo

Chani Ndalia

Thrapsano

Vlichia

Korphos

Krousonas

Miamou

Valis

Anegyroi

Panormos

Voloniès

Missyrigia

Kyani Akti

Vrisinas

Alikianos

E. KriaAdromyloi

Sitanos

Zakathos

Varvaron

AlagniDematio

Stavromenos

A. Pelagia

Akrotiri

H

H

H2S

H

H

H

H

H

H

T

TH

HTTHC

H3S

TO

H

HC

H

HO

H

HT

O

H T

H

H2TT

H3

H

H

H

H

H

HT

T

H

O

O

H4T

HH6

T

H4TOH3

O

O

H5O

H

OH3O

HT

H2

O

H

H8O2C

H

H

O

O3H2

T2 SS

T

H

H5T2O

Gt

H2

H2

H2

O Gt

H2H

O

O

H

H2T2

H2

H

H

HO

H

HH

HO2

H2S

H4

HTO2

H

OTH2

H2OH2

O

OT

HO

H

H

O

H

H2OC

H

HS

O

Go

H

H

T

H O

O

OT

O

H

H2

HO

T

O

T

H

HO

O

T

HTGh

Go

HO2Go

Gh

Gh

GhO

Gh

T

O


28

2.2. The society’s impoverishment

This type of conflictual situation is followed byeconomical difficulties leading to a generalimpoverishment of the society. One consequence ofthis situation would be the impossibility to find theprecious imported raw material used for the artisanalactivities producing luxurious objects as it wasdeveloped by the Minoan society.

2.3. The constructions and productions mediocrity

A witness of this impoverishment is the lesser qualityof workmanship, the conservation of hold models, the

reduced quantity of wonderful objects found inexcavations but also the mediocrity of constructions orreconstructions appearing in the settlements.

Effectively, when the life needs of a populationcould hardly be satisfied, the research of quality andaesthetic in architecture, as well as in the others fieldsof art, the conception of new models becamesuperfluous. The constructions are made with thecurrent, disposible materials, often with recoverymaterials. Poeple made the whole urgent works,without any attempt to obtain exceptional materials,which would require important financial means fortransportation.

Fig. 1b.

Part of the same plan showing the strong focusing of settlements aroundKnossos during the Late Minoan I (near 1500 BC) (by the author, to be publishedin Topoi).

A. Charalambos

Kato Metochi

Chersonissos

Kalo ChorioKoxari

SkotinoGouvès

Smari

KastelliApostoloi

SambaZophori

Kato Viannos

Kephali Chondrou

Nipiditos

Mathia

Avli

Kokkini Chani

AnopoliK. Vatheia

A. IoannisE. Vatheia

Elaia

Itanos/Eileithia

Amnissos

Tsoutsouros

Héraklion

KnossosGournès

Gazi

Giophyrakia

Athanatoi

Phoinikia

StavrakiaVoutès

A. Myronas

YouktasE. Archanès

Kounavoi

VathypetroA. Paraskiès

Choudetsi A. ParaskeviAstritsi Voni

ArkalochoriZindaPartheni

M. EpanosifiDamania

Arkadi

Tepheli

Ligortynos

Néochori

Kanli Kastelli

Moria

Rotasi

DorakiPanagia

Kapetania

KyparissosPyrgosSiva

KavrochoriTylissos

Moni

Prasan

EpiskopiAïtania

Choumeri

Sklavokampos

A. Pelagia

Achladia

Marathos

Vassilika AnogiaApesokari

Gortyne

Mitropoli

Levin

Krotos

A. Kyrillos

Alithini

Kasanos

Voritsi

Gergeri

Axenti

Rizikas

Gangalès

Pigaïdakia

Zaros

Chani Ndalia

Thrapsano

Vlichia

Korphos

Krousonas

Miamou

Valis

Anegyroi

Varvaron

AlagniDematio

O

H

H8O2C

H

H

O

O3H2

T2 SS

T

H

H5T2O

Gt

H2

O Gt

H2H

O

O

H

H2T2

H

H

HO

H

HH

H2

O

OT

HO

H

H

O


29

2.4. The appearance of foreign elements in the original culture

The last argument concerns the appearance offoreign elements in the original culture, like differentobject models, new techniques of workmanship andconstruction.

In Crete, this sort of evidences, decrease of theoccupied settlements number, impoverishment of thesociety, mediocrity of the constructions, appearance offoreign elements in the original culture, did not existbefore 1300 BC. Effectively, we can recognise at thistime an important stage of occupation’s decrease onthe whole territory which took place near 1300–1200BC and the appearance of mediocre constructions, for

instance in Knossos in the domestic quarter of the eastwing palace (Evans, 1900–1905), what Evans calledthe “squatters reoccupation” or in Malia in the eastpart of the Maison E (Pelon, 1967, 1970, 1980) on areduced surface of this habitation.

About the appearance of foreign elements, I justpresent here an example, that of the building called“Bâtiment Oblique” constructed in Malia in 1300 BCat the location of the North Court of the palace,abandoned long time ago, which presented a plantypically Myceanean. However, this building preservedsome Minoan characteristics like: the door openningestablished at the corner of the wall and not in themiddle as in the Mycenaean constructions (

Fig. 2a,b

).

Fig. 2.

Plan of the palace of Malia, part of the North-East wing.

Fig. 2a.

In black thick lines the « Bâtiment oblique » established on the North Court in 1300 BC,long after the abandonment of the palace (from O. Pelon, Malia Palais V in Études Crétoises XXVed. Paul Geuthner Paris, 1980).

Fig. 2b.

Plan of the « Bâtiment oblique » caracteristic of myecenaean architecture in two rooms :entrance hall and main hall, but concerving the door’s opening at the angle of the partition walltypical of minoan architecture (by the author).


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These different historical arguments, without anyreference to a stylistic discussion about the ceramicmodels contemporaneous to the Linear B tablets fromKnossos, led me to consider that the Mycenaeans hadarrived in Crete near 1300 BC.

3. The geological factors

So, how the geological factors had played a part in theevolution of the Minoan society?

From a long time people try to explain thedestructions happened in Crete during the Minoantimes by the occurrence of natural events like theeruption of the Thera’s volcano and the tsunamifollowed it, or the earthquakes (

Table 1

).

3.1. Thera’s volcano

Since the formulation in 1939 by Spiridon Marinatos(Marinatos, 1939) of the assumption that the eruptionof Thera (Santorini) was responsible for thedestruction of the Minoan palaces in Crete, numerousresearches and analyses had made to date thiseruption, often with the hope to prove that these twoevents, eruption of Thera and destruction of thepalaces were simultaneous.

The researches made since the eighties and the datafrom Thera and Crete showed that these two eventsdid not coincide. The ceramic data, discovered in therecent excavations of Akrotiri in Thera, made by Chr.Doumas, gave a datation for the remains burriedunder the volcano’s ashes that is 50 years older (1500BC) than the datation generally admitted for thedestruction of the palaces in Crete (1450 BC).

On the other hand, various geological researches andphysico-chemical analyses (Aitken, 1988; Baillie,1989; Michael, 1980; Pyles, 1989) made in the pastyears about this eruption proposed a datation near1630–1628 BC.

This difference between the two dates, the one givenby Akrotiri’s ceramic and the other by the physico-chemical analyses, gave the idea that it would benecessary to modify the datation’s system or that twodifferent events happened, the one responsible for thedate near 1630 BC, given by the organic materialsfound in Akrotiri (Michael, 1980), the ice aciditypicks (Pyles, 1989) and the trees growing circles(Baillie, 1989); the second event responsible for theash-burying of Akrotiri with a ceramic dated from1500 BC (Doumas, 1980, 1983, 1987).

On other hand, if these two dates: 1500 and 1630BC did not coincide, they put the eruption of Therabefore the Minoan palaces destruction. So, in regardto these datations, the eruption of Thera cannot havedirect effects on the Minoan palaces near 1450 BC.And that for a second reason: this eruption was anexplosive one, throwing important quantities of greyashes (and not incandescent lavas) which had entirelyrecovered the site of Akrotiri on near 30 m high. Thedestruction of this site was due to the accumulation ofash, which weight produced the collapse of roofs andfloors internally, letting the external walls intact ontheir whole height.

In Crete, on the contrary, the destructions signalled in1450 BC on the whole territory are the result of a moreor less violent burning and more or less extented on thescale of buildings as well as on the scale of settlements(

Figs. 3–4

). The more affected constructions presentedremains preserved until their basement, upon whichappeared some remains of the mud-bricks superstructurecooked by the fire and melted by its warmth.

So, it is difficult to admit that a unique eruptioncould have produced such different effects at the sametime in two different places distant one from the other.

3.2. The tsunami

The tsunami which had followed this eruption, hugewave resulting to the collapse of the volcanic cone intothe sea, could potentially carry off or submerge thecoastal buildings, but it physically neither couldproduce the fires that burnt the Minoan buildings norcould it destroy the inland settlements on the wholeterritory of Crete.

Almost the opening of the caldeira was situated west,the specialists who studied this tsunami (Meszaros,1980) asked that it passed far east from the Cretishcoasts. Effectively, traces of this tsunami had beenfound recently in Turkey at Didim and Fethye(Minoura et al., 2000) but also on the north coast ofCrete at Gouves (

Fig. 5

). Perhaps this circular wavehad reflected itself at a certain moment returningtowards the Cretish coasts. This question is not easy toresolve. It is important to determine the exactdirection and the reflection angle of this wave, withthe aim to evaluate, at first what part of Crete wouldbe affected and at second the strength of its impact onthe coasts of this island.


31

Fig. 3.

Mudbricks firecooked in Malia palace’s south wing (by the author, published inGeomorphology 2000 ; 4 : 253-66).

Fig. 4.

West House E’s part at Malia, presenting the extension of burning traces reported by thearchaeologist (by the author, published in Geomorphology 2000 , 4 : 253-66).


32

3.3. The earthquakes

Concerning the earthquakes, I had these last yearsdifferent occasions to present the results of my workin various international congresses which permittedme to publish my researches on the Cretish seismicity(Poursoulis et al., 2000), the seismo-resistantconstruction techniques used by the Minoans(Poursoulis, 2000), the destructions traces signalled bythe archaeologists (Poursoulis et al., 2000) and thecomportment of the Minoans in front of the seismicrisk (Poursoulis,.to be published). So I just wouldrapidly present here the different elements.

For the Cretish seismicity I would said that it isessentially local, moderate and strongly recurrent,

with earthquakes of small intensity: I to IV degres inthe Rossi-Forel scale, according to the records of theNational Observatory of Athens. Major earthquakeshappened every 100–500 years, according to thedifferent catalogues actually in use by the seismologist(Comninakis and Papazachos, 1982; Guidoboni,1986; Platakis, 1950). About these catalogues, I alsopublished a paper in which, as an historian, I discussedthe mistakes made in the use of the historical sourcesand the consequences they had for the knowledge ofhistorical earthquakes in Crete (Poursoulis, 2002).

About the seismo-resistant construction techniquesI would said that they are very sophisticated, conformwith the modern antiseismic tandards (Zacek, 1996)

Fig. 5.

Map of Aegean Sea and adjacent region showing areas and sites mentioned in texte. Felsic volcanicproducts of Minoan eruption are found on Aegean Sea coasts and in eastern Mediterranean deep-seacores. Tsunamigenic sediment layers were discovered in Didim and Fethye (western Turkey) and Gouves(Crete) (after Minoura et al, 2000).


33

and concerned every point of the building from itssituation on a rocky site (

Fig. 6

), the use of differentfoundation techniques according to the naturalbedrock’s depth (

Figs. 7a,b, 8a,b, 9a,b

), the three-dimensional frameworks in the walls (

Fig. 10

), to thesymmetrical plan divided into independentconstruction blocks (

Fig. 11

) and so on (Poursoulis,2000). These constructions are perfectly able to resistto the ordinary seismicity of Crete as well as to a moreviolent but rare seismicity.

The fact that the Minoans had conceived andemployed seismo-resistant construction techniquesshow us that they had the will to face the seismic riskand to resolve this problem by the regular conceptionof new and better techniques. The prosperity of theireconomy gave them the possibility to conceive thesetechniques and to extend them to all the buildings:official as well as private (Poursoulis to be published).

Finally, the destructions traces found on theMinoan remains are at first, for the destructionsignalled in 1700–1600 BC, traces of transformationof the constructions internal space organisation,whose aim was to employ the new architecturalconception of the symmetric plan divided into

independent blocks, not traces of repairingconsecutively to seismic effects; secondly, for thedestruction dated from 1450 BC, traces of burnings(Poursoulis, 1999 Poursoulis et al., 2000b).

So if it is not necessary to refer to naturalphenomena to explain an authority change in a state,then the earthquakes and the volcano of Thera cannotbe directly responsible for the Minoan buildingsdestructions; indirectly, by appearing in a difficultmoment, the natural phenomena could play a part inthe evolution of a society.

4. What I would determine?

I did not propose myself to resolve the question ofThera’s eruption datation or that of the tsunami’sdirection, two problems which needed thegeophysicists’ competences.

4.1. The volcanism

My thinking concerns the possible consequences avolcanic eruption could indirectly produce on theevolution of a society, in acting on its climate,

Fig. 6.

Rocky site on the illside for the foundation of a minoan building, settlement of Vassiliki centralCrete (by the author, published in Geomorphology 2000 ; 4 : 253-66).


34

vegetation, cultivated species and by this way on itswhole economy with a momentary weakening whichcould put the society in a vulnerable state.

By this way, the question of this eruption’s datationis important. Effectively, the date of 1628 BCattributed to this eruption by the different physico-

Fig. 7.

Natural bedrock cutted to establish the walls footing.

Fig. 7a.

At the Palace of Phaistos south-east of Crete, (by the author, published in Geomorphology 2000 ; 4 : 253-66).

Fig. 7b.

At the settlement of Vassiliki (by the author, published in Actes IV

e

Rencontre du groupe APS, 1999).

Fig. 8.

When bedrock is on surface level the foundations used are of sole footing type.

Fig. 8a.

Sole foundation type at the palace of Phaistos along the west front wall technic used by the Minoans (by L. Pernier,1935 published by the author in Actes IV

e

Rencontre du Groupe APS, 1999).

Fig. 8b.

Three modern antisismic types of sole foundations proposed by the ingeneers :a - the spin out sole foundation ; b - isolated soles ; c - general bed rock foundation sole.(by M. Zacek, published by the author in Actes IV

e


aa b

a

a) semelles filantes b) semelles isolées

longrines

c) radier général

b


35

chemical analysis, correspond to a different momentin the history of Crete from that of 1500 BC, given bythe ceramic found in Akrotiri, or from that of 1450BC, some archaeologists would always now attributeto this event. But we must also know if this impact wasas strong as generally supposed, because if largequantities of spring ashes had recovered a part or thewhole territory of Crete, with consequences, thecorruption of the soil, the destruction of thevegetation and so the abandonment of the corruptedspaces by the population for a more or less long time,we must find an interruption in the territorialoccupation for at least a certain part of the island. Nowthe study of the occupation’s evolution in Crete I dofrom the Neolothic to the Geometric period showsthat during the time covered by the different dates

proposed for this eruption, the evolution of theMinoan society in terms of expansion and prosperitydid not show any decrease. The number of occupiedsettlements on the whole territory presented a regularincrease and likewise for the cultivated spaces. Thematerial testimonies of the Minoan culture continueto be of a great aesthetical and technical quality thatshow the absence of economical weakening duringthis period.

4.2. The earthquakes

In the same way, if we suppose the intervention of anearthquake during an economical weakening phase,associated to a war conflict, we could easily conceivethat the society will lack the material means as well as

Fig. 9.

When bedrock is situated at an important depth the Minoans used depth foundation conform with the modernantisismic standards type foundation wells.

Fig. 9a.

Builded well of foundation used in the north wing of the palace of Knossos (by A. Evans, published by yhe authorin Actes IV

e


Fig. 9b.

Well foundation type in modern antisismic standard (by M. Zacek, 1996, published by the author in Actes IV

e


ab


36

the time necessary, at first for the reflexion on theresistant means of construction, at second for therepairing or construction of buildings with theresistant techniques newly developed. An earthquake,violent or without catastrophic effects, willnevertheless had aggravating consequences in addingits effects to the economical crisis.

So it is indirectly that the geological factors couldplay a part in the society vulnerability process.Effectively, in situation of economical prosperity lackduring the seismic event a society would feeldifficulties to set itself upright again.

5. The geological field work

To know in what way the eruption of Thera or theearthquakes had influenced the Minoans life instopping the economical developement of their

society, we must find effective traces of oldearthquakes, volcanic ashes and tsunami.

These last years, traces of what was identified withThera’s tephra were signalled in Palaikastro, east ofCrete, by the archaeologists responsible for this site(MacGillivray and Driessen, 1998, p. 241). This is apoint which reacquired a particular attention because,according to their position, extension and quantity,these tephra traces would represent different historicalrealities.

Effectively, a natural deposit of spring ashes wouldbe found on an important part of the island territory,including non-occupied spaces, not only inarchaeological sites. In the same way, at anarchaeological site’s scale the whole constructed spacemust present traces of these tephra. Also, theirsituation outside and around the archaeologicalremains represent a different historical situation than

Fig. 10.

Tridimentional frame work in a wall at the palace of Knossos (by A. Evans, 1921, published bythe author in Actes IV

e



37

Fig. 11.

Symetrical plan divided into independant dynamic blocs conformally to the modern antisismic standard.

Fig. 11a.

Plan of the palace of Malia presenting the division in dynamic independant blocs (by the author, published inActes IV

e


Fig. 11b.

Plan of the house Da at Malia constructed directly with the technic of symetric plan divided into dynamic independantblocs (by Demargne, Gelet de Santerre, 1953, published by the author in Actes IV

e


Fig. 11c, d.

The good and bad ways of construction for a antisismic building’s plan, according to the building’s form (byM. Zacek, 1996, published by the author in Actes IV

e


0 5 10 15 20

escaliers

couloirs, et autres espaces de séparation couverts ou semi-ouverts

délimitation des blocs de constructions ou îlots dynamiques

espaces ouverts

réduits extérieurs clos

NON OUI

joint "en baïonette"

bloc en forme de L bloc rectangulairescompacts

blocs de dimensionscomparables

blocs de formestrop différentes

blocs de dimensionscomparables

R + 2

R + 10

R + 2

R + 2

R + 10

NON OUI


38

that of a position inside them. Effectively, if the tephrawere found inside a building’s remains, under a soil inplace, they could have been intentionally bring by theinhabitants as isolating material. If they are inside thebuilding and upon the soil they could had fall downafter the abandonment and destruction of thebuilding. In all the cases, their quantities must be veryimportant, like in Akrotiri, to consider them asresponsible for a building’s destruction, a soilcorruption, an abandonment of the settlement and sofor an effect on the economical situation of the societyand its vulnerability.

A field work is already programmed with theeffective collaboration of seismologists and geologistsof the Institute of Geodynamics of the NationalObservatory of Athens and the University Aristotelisof Thessaloniki.

During a geological survey made in Crete inOctober 2001, we had marked a site propitious to theresearch of old earthquakes and volcanic ashes weprojected to do. It is a geological fault, potentiallyactive, we project to study in the next 3 years. Itpresents the advantage to be situated near a group ofarchaeological sites dating from the Bronze Age.

The geological work will be completed with theresearch of whritings about the earthquakes happenedin the vicinity of Crete. We could then obtain acatalogue of actual historical earthquakes, establishedafter a collaboration between a historian and aseismologist.

6. Conclusion

At the end of this geological study, we will be able toscientifically appreciate the effects the local seismicityof the Heraklion area could had produced on theMinoan buildings of the archaeological sites aroundthe fault studied.

We will obtain a new catalogue of historicalearthquakes, established after a severe critic ofhistorical sources which will permit to signal just theevents actually seismic and not the whole geologicalevents, as it is the case until now for the publishedcatalogues; I had shown it in a recent paper(Poursoulis, 2002).

We will also be able to estimate the impact of naturalphenomena on the evolution of the Minoan society,the part they had played in the vulnerability processwhich would permit the Mycenaeans to occupy Crete.

If the results of this work are conformed to what wehope to obtain, then we would extend these researchesin the future to the whole territory of Crete. We couldthen obtain a knowledge of the local seismicity of theisland and the impact of seismic events on the Minoansettlements of the whole territory.

Bibliography

Aitken M.J., 1988. The Minoan eruption of Thera, Santorini: are-assessment of the radiocarbon dates. In: Proceedings of aMeeting held at the British School at Athens January 1987:New Aspects of Archaeological Science in Greece,Occasional Paper no. 3 of the Fitch Laboratory Athenes, pp.19–24.

Baillie M.G.L., 1989. Irish tree-rings and an event in 1628 BC.Nature, 4–20.

Bennet J., 1985. The structure of the linear B administration atKnossos. Am. J. Archaeol. 89, 231–249.

Bennet J., 1990. Knossos in context: comparative perspectives onthe linear B administration of LMII–III Crete. Am. J.Archaeol. 94, 193–211.

Comninakis P., Papazachos C., 1982. A Catalogue of HistoricalEarthquakes in Greece and Surrounding Area 479 BC–1900AD. University of Thessaloniki Geophysical LaboratoryPublication n

o

5.Doumas C., 1980. La stratigraphie d’Akrotiri, Thera and the

Aegean World 2nd International Scientific Congress,Santorini, Greece, about 1978. London, pp. 777–782.

Doumas C., 1983. Thera: Pompei of the Ancient Aegean,London.

Doumas C., 1987. Akrotiri on Thera and the need forinterdisciplinary action, Pact 18 III-I 1987: La protectiondes monuments archéologiques dans les zones à risquessismiques. CUEBC Ravello Italie, 137–141.

Duhoux Y., 1976. Aspects du vocabulaire Mycénien. A. Hakkert,Amsterdam.

Duhoux Y., Morpurgo-Davis A., 1985. Linear B: a 1984 survey,Proccedings of the Mycenaean Colloquium of the 8thCongress of the International Federation of the Societies ofClassical Studies 1984, Cabay, Louvain la Neuve.

Evans A., 1900–1905. Rapports de fouilles de Knossos, Ann. Br.School Athen.

Guidoboni E., 1986. I terremoti prima del Mille in Italia enell’Area Mediterranea (Ed.) Istituto Nationale di Geofisica,pp. 575–724.

MacGillivray J.A., Driessen J., 1998. Fouilles à Palaikastro 1994–1996. Ann. Br. School Athen 93, 221–249.

Marinatos S., 1939. The volcanic destruction of Minoan Crete,Antiquity XIII, 425–439.

Meszaros S., 1980. Some words on the minoan tsunami ofSantorini, Thera and the Aegean World 2nd InternationalScientific Congress Santorini, Greece about 1978. London,pp. 257–261.

Michael H.N., 1980. Radiocarbon dates from the site of AkrotiriThera 1967–1977, Thera and the Aegean World 2nd


39

International Scientific Congress, Santorini, Greece about1978. London, pp. 791–795.

Minoura K., Imamura F., Kuran U., Nakamura T., PapadopoulosG., Takahashi T., Yalciner A., 2000. Discovery of minoantsunami deposits. Geology 28, 59–62.

Palmer L.R., 1969. A new guide to the palace of Knossos. Faberand Faber, London.

Pelon O., 1967. La maison E de Mallia, Bulletin deCorresondance Hellénique.

Pelon O., 1970. Malia Maison III Maisons et Quartiersd'habitation. Etudes Crétoises XVI, Paul Geuthner, Paris.

Pelon O., 1980. Malia Palais V. Études Crétoises XXV, PaulGeuthner, Paris.

Platakis E., 1950. Les séismes de Crète, Kritika Chronika, 1950,463–526.

Popham M.R., 1970. The destruction of the palace at Knossos:pottery of the late minoan IIIA period, Studies inMediterranean Archaeology, Vol. XII.

Poursoulis G., 1999. La Destruction des Palais Minoens. Thèsede Doctorat, Univertsité de Paris I, Paris.

Poursoulis G., 2000. Des techniques sismo-résistantes dans lesédifices de l’âge du Bronze en Crète. In: Actes des IV

e

Rencontres du Groupe APS (Archéologie-PathologieSismologie): Archéosismicité et Vulnérabilité du BâtiAncien, Perpignan, Mai 1999, pp. 127–152.

Poursoulis G., 2002. Archéosismicité et connaissance du risquesismique par les Minoens: de l’usage des catalogues deséismes historiques. In: Actes des V

e

Rencontres du GroupeAPS: Archéosismicité et Sismicité historique contribution àla connaissance et à la définition du risque, Perpignan Avril2000, pp. 11–38.

Poursoulis G., à paraître. Le comportement des Minoens face auxséismes: fatalisme ou détermination ? In: Topoï, Actes de laTable Ronde du 5 Juin 2001 CNRS Maison de l’OrientMéditerranéen.

Poursoulis G., Helly B., Dalongeville R., 2000. Destruction desédifices minoens et sismicité récurrente en Crète,Géomorphologie 4, 253–266.

Pyles D.M., 1989. Ice-core acidity peaks retended tree growthand putative eruptions, Archeometry, 31.

Zacek M., 1996. Construire Parasismique (Éd.) Parenthèses,Marseille.

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