Wednesday, August 30, 2017

Bronze-Age faulting at Mycenae (Greece) and a glimpse at cultural responses

Bronze-Age faulting at Mycenae (Greece) and a glimpse at cultural responses

Eric R. Force

Abstract:  The upper citadel at Mycenae is the upthrown block between two active normal faults, both represented by prominent scarps.  One of these faults is known to have moved during Mycenaean times (in this case between about 1650 and 1300 B.C.),  and a temple complex is draped across a fault scarp along a splay of the other, the more famous Lion Gate fault zone. The sole outcrop exposure of this fault scarp within the temple complex was already thought  to have had “cultic” significance. The scarp itself provided the focus for the arrangement of adjacent cultic paraphernalia. Inhabitants of Mycenae, accustomed to the movement of faults in their midst as well as accompanying earthquakes, responded in a cultic/religious framework reflecting an appreciation of a link between these phenomena and their relation to the “underworld.”


A role of tectonic activity in ancient Hellenic cultures has recently been documented (e.g. de Boer and Sanders 2005,  Force 2015).  Currently, the review of Stewart (in press) is finding that temples and sanctuaries of classical ancient Hellenic culture took advantage of active faults in various ways--topographic scarps formed along the planes of such faults are commonly found in such association, for example.  Stewart suggested that this association at Mycenae is possible.  The numerous implications of such early religious/tectonic links there, including what form they might take, require testing of this hypothesis.
 The hilltop citadel of Mycenae at the head of the Argos basin gives its name to the entire Late Bronze-Age culture of mainland Greece. “Well-built Mycenae” was a referent for several aspects of later classical Greek culture via Homer.  It was a major center of Mycenaean culture from at least 1600 B.C. until this culture ended (and the Bronze Age ended with it) after 1200 B.C. Its position at the head of an extensional basin produces high seismicity today (e.g. Ambraseys 2009), and its geology reveals a Holocene history of complex tectonic behavior.

Local tectonic setting
Two of the citadel’s most famous cultural features are themselves tectonic features—the Lion Gate on its western margin (FIG 1) and the Perseia spring on its northern margin. These are located along recently active faults that form the SW and NE margins of the upper citadel, respectively (FIG. 2).  The faults are both steeply dipping normal faults, i.e. upper block thrown down, but dip away from each other so that the citadel between them is a horst, i.e. a block raised up relative to those on either side. 
The bedrock wall on which the NE bastion of the Lion Gate rests is itself a fault plane striking SE and dipping about 60 degrees SW (FIG. 1)  It preserves details of its movement (down-dip ”slickensides”), showing its last movement to be very recent in a geologic sense, as erosion degrades such features (Stewart and Hancock 1988).  The Lion Gate and the “cyclopean” wall built atop this bedrock, however, show that this fault has not moved since their construction in the LH III A2 or early LH III B period (French 1996), ca. 1350-1300 B.C.  For convenience I will refer to this as the Lion Gate fault zone.
The NE-dipping fault forming the NE margin of the citadel,  mapped and described by Maroukian et al. (1996), also has cyclopean walls built atop its exposures (their fig. 3). ).  I will refer to this fault as the Perseia fault.  The Perseia spring along the fault plane feeds a cistern accessed by three flights of steps within a corbel-vaulted tunnel starting from inside the citadel, a design for surviving siege (FIG. 2). Maroukian et al. (1996) made another important observation:  the Perseia fault, present as a continuous fault scarp (readily visible on Google Earth) dammed the Havos stream SE of the spring (FIG. 2), and the 2.5 m of sediments that filled the impoundment contain only “Mycenaean” sherds at the base, and only significantly more recent sherds higher within this fill.  Maroukian et al. conclude that this drainage disruption occurred in the Mycenaean period, i.e. probably 1650 to 1200 B.C  However, an additional constraint is the age of walls built on its scarp, about 1350-1300 B.C.., suggesting the available period of movement is about 1650 to 1300 B.C.
This is consistent with the observation of Maroukian et al. (their fig. 5) that the lowest 1.5 m of the Perseia fault plane is fresh, complete with slickensides and showing no evidence of weathering or erosion, in contrast to the weathered and eroded 1.5 m portion above.  Since the lower interval corresponds with the part of the fault plane that impounds Mycenaean-age sediment, the lower portion must have been exposed by fault movement at that time. We must conclude as did Maroukian that faulting occurred “during Mycenaean time”, and we can assume that Mycenaeans were present to observe at least the changes in exposed fault planes. 
Earlier offset followed by partial burial in the channel of the Havos drainage is documented by Maroukian et al.  (1996) along the Perseia fault.  Also known is earthquake damage to the citadel during LH III B Middle time, about 1250 BC (French 1996) and probably also in early LH III C (about 1200 BC; Kilian 1996).  There is no evidence of fault offset in Mycenae for these later seismic events, but clearly Mycenae was seismically risky in prehistory, as it has been since.
There is no direct evidence that the Lion Gate fault moved in the 1650-1300 B.C. interval as the Perseia fault did, but the similarity of the faults and their symmetry certainly suggest the possibility.  The extension of the Lion Gate fault through the citadel is uncertain; based on Google Earth images I would extend it as a slightly sinuous fault zone trending first about S30W across the citadel, then S40W to the lip of the Havos stream’s ravine.  A historical image of the fault rock at the Lion Gate (e.g. Taylour 1983 fig. 94) as well as my own observation (FIG. 1) show that it is not a single plane.  Google Earth images show a conspicuous “avenue” of poor rock exposure about 15-30 m wide along the trend of this fault as it is exposed at Lion Gate (FIG. 2).  Foundations of Mycenaean structures are conspicuously absent in this avenue, either because of deeper burial on the down-dropped block, or an ancient perception of great seismic risk. Indeed it is this zone that divides Mycenae into a lower and an upper citadel.

The Lion Gate fault zone in the temple complex

The evidence of Mycenaean-age fault movement might moderate our surprise in finding it involved in the architecture and culture of the lower citadel.  Excavation by Taylour (1970) of a temple complex of about 1300 B.C. in the lower citadel documented a planar bedrock exposure with about the same trend and slope as the fault-scarp at the Lion Gate (and quite unlike that of country-rock bedding).  That is, this plane strikes NW-SE and dips steeply SW.  The exposure occurs in a back room of the temple dubbed “the alcove” by its excavators (FIG. 2).  The details of architecture, cultic offerings, etc. prompted Taylour to suggest that the rock exposure itself was of some “cultic” significance.  He pointedly repeated this suggestion in a later summary (Taylour 1983, p. 50), adding details such as the planar shape and unaltered natural surface of this outcrop.  Taylour (1983, p. 56) was willing to consider that this outcrop might be central to activities at the temple, the cultic/religious significance of which is not in dispute.
The location and elevation of this temple and its outcrop/alcove are quite close to my projection of the Lion Gate fault zone toward the SE; they lie SW of it (FIG. 2) and topographically about 8 m below its elevation at the Lion Gate or its SE projection, as might be expected from the fault’s SW dip.  Thus it is likely that the outcrop in the alcove is part of the Lion Gate fault zone in the broad sense. Taylour’s (1970, 1983) descriptions of the outcrop are insufficient to determine whether it is fault-rock, and no photograph that includes it (Taylour 1983 fig. 24, see also Moore and Taylour 1999 including microfiche) is useful for this purpose, but its attitude (Taylour 1970 fig. 1; 1983 fig. 26) is as one would expect for an exposure of the Lion Gate fault zone, and is not that of regional bedding.
This outcrop is continuous and along-trend with the SW margin of bedrock shelves on either side of the temple complex per se, i.e. under South House annex to the NW and the megaron to the SE (FIG. 3).  That is, this margin is an abrupt down-to-SW step in the bedrock surface as shown by excavations along trend (p. 32 and 33 respectively in Taylour 1981), perhaps as far as the similar bedrock shelf within grave circle A (Wace 1921-3).
The excavation literature reveals details of bedrock exposed in the temple complex (Taylour 1981, Moore and Taylour 1999). They show that Taylour’s outcrop in the alcove abruptly separates plastered bedrock floors to the NE 1.75 m higher (room 19, known as the Room of the Idols) than that to the SW (room 18, in the central temple).  A considerable amount of bedrock excavation and removal would be required to produce this relation, and clearly would alter the natural surface of the exposures in the alcove. So the outcrop itself represents a SW-dipping fault plane, this exposure of which forms a fault scarp (FIG. 3).  Room 19 is on the upthrown block, the alcove floor and room 18 on the downthrown block.  The fault plane and its scarp elsewhere in the temple complex is obscured by walls and stairways; it trends obliquely under the SW corner of room 19 and the stairway leading up to it (FIG. 3).  Its extensions to the SE and NW are marked by the bedrock shelf margin.  The temple complex and its neighboring structures are thus draped across a fault scarp, apparently a splay within the Lion Gate fault zone. However, the only exposure of the fault plane itself after temple-complex construction would have been that in the alcove.

Apparent cultic/religious responses

Construction of the temple complex required intimate knowledge of the fault scarp there, and obscured it in all but one place.  Three additional features of the alcove and adjacent room 19 suggest that Taylour (1970, 1983) was correct in assigning a cultic significance to the alcove outcrop, and that this significance relates to the fault scarp exposed there.  First, the anomalous concentration of snake figurines near the fault scarp and its hidden extensions suggests an association with the underworld (Taylour 1983, p. 53-55, Moore and Taylour 1999, p. 117).
Second, the excavators found that most figurines in these two rooms were broken in half, one half of which was found in each room (Moore and Taylour, 1999, p. 17).  Thus half of each of these figurines was found on the upthrown block and half on the downthrown block of the fault.  The geometry of this arrangement is roughly symmetrical about the fault scarp, though subsequent construction obscured this even from excavators.   It seems likely that the placement of figurines was intentional, and reflects some attempt at correlation or landscape reconstruction across the offset, i.e. “stitching” together their landscape.  If these particular figurines are heirlooms as suggested by Taylour 1983, p. 53, perhaps appropriate terms describing their placement would be commemoration or even re-enactment of the fault’s movement. Following a later earthquake of ca. 1250 B.C. (Taylour 1983, French 1996) room 19 and its cultic paraphernalia were walled off.  The placement  of figurines is thus constrained between construction of the rooms and the walling off of one of them.  If the breaks in the figurines are a result of the 1250 B.C. earthquake, then their arrangement is constrained between that earthquake and the walling-off of room 19.  However, Hinzen et al. 2014 found such breakage etc. of these figurines unlikely for this particular earthquake.
Third, leaving only one exposure of the fault plane and obscuring it elsewhere suggests an aspect of the alcove outcrop that could be like a museum or sanctuary.

Conclusion and speculation
            First, it seems clear that ties between faults and cultic/religious practices documented for ancient Hellenic cultures of later periods extend back into the Mycenaean era.  Indeed, these ties are quite vivid, though mysterious to us. 
Available evidence strongly suggests that the Mycenaeans would have been cognizant of fault-scarp planes as features of significance; they would have observed that their precious spring was along one of the two conspicuous scarps (the Perseia fault) that was growing in height, and that the upper part of their citadel was being uplifted, accompanied no doubt by earthquakes.  They would have observed a similarity of the Perseia scarp to that at the Lion Gate and the alcove, and generational memory might even have included the latter’s appearance after an earthquake. It would be a powerful experience to see fault scarps appear in the aftermath of an earthquake, forming a continuous curtain that offset their landscape. Links among landscape, solid-earth structure, and earthquakes would become apparent.
It also appears that their observations had cultic/religious responses, as they linked the surface of their citadel to their underworld.  Indeed Taylour  (1983 p. 56) thought the significance of his “cultic” outcrop with attendant snake figurines was that of a link to the underworld, even though he was not aware of this outcrop as a fault scarp.   Mycenaean awareness of a “before-and-after” aspect of their faulted landscape is apparently marked by their remarkable arrangement of cultic figurines in the temple complex. 
Thus Mycenaean need for a religious response to their tectonic environment required an underworld aspect, an earth-structure aspect, and an earthquake aspect.  The latter two aspects recall the suggestion by Polimenakos (1996, p. 252-255) that our earliest glimpses of Poseidon (PO-SE-DA-O-NE in Linear B) include both of these, i.e. as earth-smith and earth-shaker, though navigation of the underworld might have required additional deities.
The fascinating possibility suggests itself that the inhabitants of ancient Mycenae appreciated something about their local tectonic processes as these unfolded before them.  They probably had a precocious appreciation that earthquakes and faults are related.  Despite seismic/faulting disruption they responded in several constructive ways:  they took advantage of the increased elevation of their upper citadel by building walls (“Well-Built”) on the margins of uplifted blocks, and they took advantage of springs along them.  But they also apparently envisioned these processes as links to their underworld, enshrining them in various ways and commemorating their tectonic history.  Perhaps it is no accident that the Lion Gate itself displays this tectonic-cultural relationship.

Recommended further work

Results described here suggest further avenues of research for confirmation and for exploring implications.  Perhaps most urgent is the need for more specific ages for the “Mycenaean” sherds in basal sediments impounded behind the Perseia fault-scarp dam on Havos stream (cf.. Force 2004 for criteria of dating using detrital sherd assemblages).   Work on the age and geometry of faulting along the Lion Gate zone is also needed; examination of the Havos stream’s ravine might be helpful in this regard.  A proper description of the rock outcrop in the alcove would be useful. I have a hunch that in view of results presented here, the age and nature of figurines in the temple complex will be re-evaluated.


This manuscript is meant thus far as a discussion paper.  I would like to acknowledge the influence on this presentation of scholars no longer with us:  Jelle de Boer, Klaus Kilian, and of course Lord William Taylour.  Special thanks are due Jeremy Rutter for advice, encouragement, edits, and lessons in “Prehistoric Aegean Archaeology.” George Davis, David Soren, Ed Wright, and Elisabeth French have also encouraged and/or advised.  Jane Brandon Force was my full-time judge of logic and plausibility, and Germaine Shames helped with logistics.   I take total responsibility for my conclusions.

Figure 1—Photograph of the back side of Lion Gate with slickensided fault rock visible through it, and “cyclopean” walls atop and beside it.

Figure 2—Sketch map of Mycenae showing citadel walls (solid),  Perseia and Lion Gate fault and fault zone (dashed), and Havos Stream ravine (dotted).  Upper citadel upthrown relative to blocks across these faults.  Lettered localities:  A, Lion Gate, B. “alcove” outcrop, C. Perseia spring and cistern, D. Section of Havos Stream dammed by Perseia fault. 

Figure 3—Environs of the Temple Complex at Mycenae after Taylour 1983, annotated in red with the normal fault at the elevation of bedrock in room 18.  U, upthrown block; D, downthrown block; ticks on fault in the direction of steep dip.  Floors in rooms 18 and 19 are plastered bedrock.

References (Stiros and Jones appearing so often below refers to Stiros, S., and Jones, R. E., 1996, Archaeoseismology:  British School at Athens, Fitch Laboratory Occasional Paper 7.)

Ambraseys, N., 2009, Earthquakes in the Mediterranean and Middle East:  a multi-disciplinary study of seismicity up to 1900:  Cambridge Press.

deBoer, J. Z., and Sanders, 2005, Earthquakes in human history:  Princeton University Press.

Force, E. R., 2004, Late Holocene behavior of Chaco and McElmo canyon drainages (SW US): a comparison based on archaeologic age controls:  Geoarchaeology v. 19, p. 585-609.

Force, E. R., 2015, Impact of tectonic activity on ancient civilizations:  Lexington.

French, E. B., 1996, Evidence for an earthquake at Mycenae, in Stiros and Jones, p. 51-54.

Hinzen, K.G., Vetters, M., Kalytta, T., Reamer, S.  K., and Damm-Meinhardt, U., 2015, Testing the response of Mycenaean figures and vessels to earthquake ground motions:  Geoarchaeology v. 30, p. 1-18.

Kilian, K., 1996, Earthquakes and arcahaeological context at 13th century Tiryns, in Stiros ad Jones, p. 63-68.

Maroukian, H., Gaki-Papanastassiou, K., and Papanastassious,  1996, Geomorphic-seismotectonic observations in relation to the catastrophies at Mycenae, in Stiros and Jones, p. 189-194.

Moore, A. D., and (posthumous) Taylour, W. D., 1999, Well Built Mycenae--The Temple Complex:  The Helleno-British Excavations within the Citadel at Mycenae 1959-1969, fascicule 10, Oxbow Books, Oxford.

Polimenakos, L. C., 1996, Thoughts on the perception of the earthquake in Greek antiquity, in Stiros and Jones, p. 253-260.

Stewart, I. S., in press, Seismic faults and sacred sanctuaries in Aegean antiquity:  Proceedings of the Geologists’ Association

Stewart, I. S., and Hancock, P. L., 1988, Normal fault zone evolution and fault-scarp degradation in the Aegean region:  Basin Research v. 1, p. 139-153

Taylour, Lord W, D., 1970, New light on Mycenaean religion: Antiquity v. 44, p. 170-180.

Taylour, Lord W. D., 1981, Well Built Mycenae—The Excavations: The Helleno-British Excavations within the Citadel at Mycenae 1959-1969, fascicule 1, Oxbow Books, Oxford.

Taylour, L. W., 1983, The Mycenaeans, 2nd ed.: Thames and Hudson

Wace, A. J. B., 1921-3, Excavations at Mycenae VIII: Lion Gate and Grave Circle area:  Annual of the British School of Archaeology at Athens v. 25. 

Wednesday, March 15, 2017

Seismic environment of ancient Egyptian cultures

Seismic environment of ancient Egyptian cultures, with emphases on the predynastic era and on extensional tectonics

Eric R. Force

The distinctive and complex ancient Egyptian civilization, certainly one of the greatest in antiquity, endured for over 2500 years.  One of its peculiar features is its cultural conservatism over this long time period, noted by many authors.  A possible relation of this conservatism to its tectonic quiescence has been addressed by a few of them, including myself (Force 2015).
Two bodies of information of which I was previously unaware inform this posting.  One is the growing literature on predynastic cultures of both Upper and Lower Egypt, pertinent to any original cultural adaptations to Egypt’s tectonic environments.  The other is a growing awareness of peculiar tectonic activity in the Luxor-Thebes-funerary valleys area of Upper Egypt.  This latter I previously treated as a single exceptional event in antiquity (Force 2015 p. 50), but in an overall pattern of Egypt’s tectonic quiescence—a pattern that is unlike that of other ancient complex cultures (noted also in the review by Robinson 2015). 
Egypt’s ancient complex cultures are along the Nile River and its delta, and this valley in Egypt and Sudan is not on a tectonic plate boundary.  The valley itself has not been subject to large earthquakes.  A transtensional plate boundary between African and Arabian plates follows the Red Sea but extends up its Gulf of Aqaba arm and becomes the transcurrent Dead Sea Rift.  Moderate seismic activity is common along the Red Sea and its Gulf of Suez arm (Ambraseys et al. 1994, Badawy 2005).  This locus is about 200 km to the east of the Nile (except at its Qena bend where it can be as little as 100 km away).  However, an extension of this locus as moderate extensional seismic activity crosses into Lower Egypt near Cairo.  Here soil conditions allow liquifaction, increasing the risk of damage (El-Araby and Sultan 2000).  Lower Egypt also commonly “feels” strong earthquakes in the Mediterranean, and coastal delta communities are at risk of tsunami from that direction (Ambraseys et al. 1994, Stanley and Jorstad 2005).  Historical earthquakes thought by Ambraseys to have epicenters near the Nile include those of 1847, 1974. and 1992 in Lower Egypt and 1981 in Upper Egypt; he dismisses or relocates many others.  In summary there is evidence from neither tectonic theory nor historic record to associate ancient Egyptian cultures with strong pervasive seismicity.

New views of predynastic cultures

Prior to the unification of ancient Egypt as one state about 3100 B.C., Lower and Upper Egypt were distinct entities, at times separated by the stretch of Nile between almost 27 and 29 degrees north latitude.  Recent work (Davies and Friedman 1998, Brewer 2005, Cialowicz 2008) has shown they were quite different—in contact for some easily portable trade items but without much cultural influence. 
Predynastic Lower Egypt, much of it in the delta, was in some contact with Canaan and Mesopotamia, but the degree of this contact varied, from moderate in the early part of the 4th millennium B.C. (Faltings 1998, 2002), to insignificant in a following period that lasted over a hundred years.  Literature at my disposal suggests that Lower Egypt in this period remained a rather simple culture, trading with the Levant presumably by sea, but without many of the coeval features of cultural complexity there. 
Predynastic Upper Egypt, centered first in Hierakonpolis (Friedman 2017) from about 3500 B.C. was a relatively complex culture, boasting public works, religious architecture, and exquisite ceramic and stone vessels, gold artwork, and chipped-stone artifacts (Davies and Friedman 1998). Contact with SW Asia was via overland routes to the Red Sea (Brewer 2005).   Some local traditions initiated in this region persisted literally for millenia, and are quite distinctive. 
The takeover of Lower Egypt by Upper Egypt, probably about 3100 B.C., is attested both archaeologically (Cialowicz 2008) and symbolically (via the Narmer Palette, etc.).  Thus began the era of a unified Egyptian state that persisted through antiquity, on occasion with different ethnic rulers but remarkably similar customs. 
The separate evolutionary paths of Upper and Lower Egypt through the predynastic period suggest primary (“ pristine”) cultures despite some sporadic contact with each other and the outside world.  Some of the characteristic features of the long-lived Egyptian civilization were established in predynastic Upper Egypt, and many more in the first few dynasties of the Old Kingdom, i.e. latest Stone Age to earliest Bronze Age. 
Tectonic influences on settlement and culture are commonly apparent in these early stages of complex cultures. However, I cannot say that I see any such influences in the case of Egypt. 

Paleoseismicity and possible relation to extensional tectonics

In 2015 I referenced the work by Karakhanian et al. (2010), who presented evidence of an earthquake in the New Kingdom era at Luxor.  I did not, however, treat this event as part of a regional pattern.  Several lines of evidence suggest this approach be taken now.
Several suggestions of ancient earthquakes in Upper Egypt remain unsubstantiated.  However, the evidence of Karakhanian  et al. (2010) for an ancient earthquake seems persuasive; it consists of damage and ancient restoration of the Colossi of Amenhotep III, ancient liquifaction exposed in trenches around that temple, and regional disturbances as described below.  They propose a local earthquake of magnitude about 6 between about 1200 and 900 B.C. based on paragenesis of damage relative to archaeologic features of known age, and radiometric dating of disturbances exposed in trenches.  Much of this period is one of very little written record in Egypt’s history (21 and 22nd dynasties e.g. Davies and Friedman 1998).
Ancient ground disturbances were noted by Karakhanian et al. (2010) throughout the Thebes-Luxor area.  In addition, listric faulting of Tertiary sedimentary sections was observed by both Cobbald et al. (2008) and Karakhanian et al. (2010) throughout the entire funerary valley area of several square kilometers on the NW bank of the Nile opposite Luxor.  Relations between normal faults and funerary features described by Karakhanian et al. (2010) suggest faulting about 1150 B.C.  However, it is unclear whether these faults are better described as huge landslides or crustal extensional features.  This evidence of local ancient tectonic activity matching intense ancient cultural activity is intriguing. 
With this activity in mind it is worth revisiting patterns of more recent and modern seismicity of Egypt.  The Thebes/Luxor area is on the southern stretch of the Qena bend of the Nile, the largest such bend in Egypt.  Thus the river is locally oriented NE-SW, parallel to the strike of listric faulting documented by Cobbald et al. (2008) and Karakhanian et al. (2010).  Other faults with this trend along this stretch of river are known (e.g. El-Araby and Sultan 2000), and some seismicity of transcurrent type has been recorded there (Badawy 2005).  Within 200 km to the south of this stretch is a zone of recorded seismicity and east-west faults (El-Araby and Sultan 2000).  A series of small earthquakes occurred in 2003/4 within 50 km to the south (Badawy et al. 2006) where almost none had been recorded before.  The distribution and temporal pattern of Egypt’s historic seismicity varies widely (Badawy 1999).  Thus there seems no reason to doubt that the Thebes/Luxor/funerary valley area was subject to some sporadic seismicity in antiquity.


Ancient Egyptian civilization as a whole must still be viewed in a nearly quiescent tectonic environment.  The evidence presented here for the Thebes/Luxor area is intriguing, as it forms part of a pattern for upper/middle Egypt.  But mid-plate settings commonly have tectonically active locales.  For ancient settlements along the Nile, only Lower Egypt and a small part of Upper Egypt likely experienced seismic activity, mostly moderate. 
New work on the character of predynastic culture of Upper Egypt emphasizes its primary nature in a mostly-quiescent tectonic environment. The relation between cultural conservatism and tectonic quiescence noted for many ancient cultures (Force 2015) still seems valid in view of evidence for Egypt presented here—indeed Egypt is probably still the best example of this relation.  However, ancient Egypt’s emergence as an exceedingly complex culture in a quiescent tectonic environment remains unusual. 


Ambraseys, N. N., Melville, C. P., and Adams, R. D., 1994, The seismicity of Egypt, Arabia, and the Red Sea:  Cambridge Univ. Press.

Badawy, A., 1999, Historical seismicity of Egypt:  Acta Geodetica et Geophysica Hungarica, v. 34, p. 119-135.

Badawy, Ahmed, 2005, Seismicity of Egypt: Seismological Research Letters, v. 76, p. 149-160. 

Badawy, A., Abdel-Monem, S. M., Sakr, K., and Ali, Sh. M, 2006, Seismicity and kinematic evolution of middle Egypt:  Journal of Geodynamics v. 42, p. 28-37.

Brewer, D. J., 2005, Ancient Egypt: foundations of a civilization:  Pearson-Longman, London

Cialowicz, K. M., 2008, The nature of the relation between Lower and Upper Egypt in the Protodynastic period—a view from Tell El-Farkha, in Egypt at its Origins II, B. Midant-Reynes and Y. Tristant, eds., p. 501-513.

Cobbold, Peter, Watkinson, John, and Cosgrove, John, 2008, Faults of the pharoahs:  Geoscientist v. 18 #6. (online only at 3994.html).

Davies, Vivian, and Friedman, Renee, 1998, Egypt Uncovered:  New York: Stewart Tabori and Chang

El-Araby, Hesham, and Sultan, Mohamed, 2000, Integrated seismic risk map of Egypt: Seismological Research Letters v. 71, p. 53-66.

Faltings, Dina, 1998, Canaanites at Buto in the early Fourth Millenium BC:  Egyptian Archaeology, v. 13, p. 29-32.

Faltings, Dina, 2002, The chronological frame and social structure of Buto in the Fourth Millenium BCE, in Egypt and the Levant:  interrelations from the 4th through the early 3rd Millenium B. C. E.,  C. M. Van den Brink and T. E. Levy, eds. , p. 165-170.

Force, E. R., 2015, Impact of tectonic activity on ancient civilizations: recurrent shakeups, tenacity, resilience, and change:  Lexington Books.

Friedman, Renee, 2017, City of the hawk, in Egypt—treasures, sites, and ancient culture:  Archaeology Magazine special issue Egypt, p. 40-46. 

Karakhanian, A., et al. 2010, Archaeoseismological studies at the temple of Amenhotep III, Luxor, Egypt, in Ancient earthquakes, Sintubin, M. et al., eds.: Geological Society of America Special Paper 471, p. 199-222. 

Robinson, Andrew, 2015, Geophysics: vast forces underfoot:  Nature v. 528, p. 35-36.  

Stanley, D. J., and Jorstad, T. F., 2005, The 365 A.D. tsunami destruction of Alexandria, Egypt:  Geol. Soc. America Abstracts, v. 37, p. 75

Friday, January 20, 2017

Some varieties of ancient cultural responses to tectonic activity

Some varieties of ancient cultural responses to tectonic activity[i]

Eric R. Force

Observing a remarkable spatial correspondence between loci of ancient complex cultures and the margins of tectonic plates[ii], I suggested in my 2015 book[iii] that active tectonism along such margins forced the pace of change in cultures along them, resulting in rapid cultural evolution.  Associated evidence came from varying the geometry and scale of spatial analysis, neutralizing the effects of requisite factors, comparing rates of change in active vs. quiescent environments, kinetic mapping of the propagation of complexity, and recording the dynamics as preserved in ancient literatures and architecture[iv].

This posting/paper examines the inherent differences in cultural responses to different types of tectonic activity.  The responses noted in my book were largely to seismic activity, as volcanism was absent in most of the areas I treated, and tsunami were not specifically addressed [v].  However, these other tectonic factors in cultural response are of importance, notably the western hemisphere and the western Pacific.  It is of interest and practical use to analyze the structure of typical cultural response types.[vi]

Seismic activity in the ancient world commonly led to both tenacity and resilience.  Damaged or destroyed settlements and ceremonial sites were generally rebuilt at the same location, despite location near active faults.  Earthquakes generally do not compromise the local bases of subsistence, and directions of avoidance were unclear in antiquity.   Thus sites favored for any reason[vii] were tenaciously rebuilt, but generally improved with new technology more resistant to damage, along with other changes demonstrating cultural resilience[viii].  These factors are those that eventually resulted in greater cultural complexity in comparison to coeval quiescent sites, where no such responses were needed.  The historic period also furnishes many examples of seismic activity forcing the pace of change, with both tenacity and resilience as responses[ix]. 

In comparison, the effect of volcanism commonly compromises the bases of subsistence in settlements freshly covered.  On the other hand, direction of avoidance is generally obvious, from flow margins and direction, and/or wind direction for ash plumes.  A common response is temporary abandonment[x], with migration to sites less impacted, or even benefitted[xi].  Where soil formation is rapid, abandonment may be relatively brief.  In-migration may not have the same cultural identity, however.  In antiquity, the cultural response to tectonic environments was not always toward complexity, as pertinent useful change was not obvious[xii].

Tsunami result from offshore earthquakes, volcanism, and sometimes submarine slides[xiii], so are indirect results of tectonic activity, most commonly quite local but in some cases projected onto quiescent environments across seaways[xiv]. A culture’s tsunami vulnerability along its coasts generally deprives it of the rich resources and trade potential there[xv].  Migration to adjacent uplands and headlands is a common response to new awareness of the danger[xvi]. Memories of this may be short-lived, but some ancient cultures went to some lengths to preserve awareness of tsunami via traditional narratives[xvii], and/or they structured society to minimize the danger[xviii].  Cultural change if any may be minimal, indeed in some ancient cases retrograde[xix]. 

I conclude that despite wide varieties in reportage of ancient earthquakes, volcanic eruptions, and tsunami, we can see some differences based on literary, ethnographic, and archaeological records.  Tenacity tends to be a typical response to earthquakes, in some ways a default response due to apparent great dimensions of affected area and lack of obvious avoidance directions.   In contrast, avoidance directions are more apparent for volcanic events and tsunami.  For tsunami, abandonment can be long-lasting, whereas for volcanism, eventual return is a typical pattern once agriculture is again possible. Tsunami may not result in the long-term increase in cultural complexity seen for seismicity due to the loss of coastal resources.

To some extent, ancient responses to tectonic activity are preserved in the modern era, including the differences described above.  Indeed, the only important change is the modern knowledge of distribution of seismic and other risks of natural disaster—and the importance of maintaining strategic sites is clearly the greater factor in our world.  Others remain the same—and modern and ancient instincts are basically the same, being inherent to our species.  Thus understanding of ancient responses may be useful in our modern world, as they are unvarnished by recently added considerations.  In any case, unraveling the cultural responses to different types of tectonic activity is a step toward improved response, especially where more than one tectonic phenomenon is involved.

[i] Proper references appear in my book, my numerous blog-posts, and my other publications.  Here I would like to acknowledge the most important authors that have influenced my conclusions, rather than presenting voluminous references.  Especially influential for this paper/post were my co-panelists at a 2016 Society for Applied Anthropology convention, namely Gina Barnes, Wayne Howell, Bruce McFadgen, Nick Roberts, John Clague, and Susanna Hoffman.  As always, I appreciate the advice of  Claudio Vita-Finzi, Manuel Berberian, the late Jelle de Boer, Chuck Adams, Bob Tilling, David Soren, George Davis, Emma Blake, and Jane Brandon Force.
[ii] Demonstrated probabilistically by comparing average distance between ancient complex cultures and on-land convergent or transcurrent plate boundary, as a fraction of available land area.
[iii] Force (2015) “ Impact of tectonic activity on ancient civilizations . . .” published by Lexington Books.
[iv]Respectively consisting of 1) spatial focus on continent-scale transects and culture-scale comparison of tectonism and ancient culture; 2) showing that requisite climates, soils, irrigation and transportation potential, etc. are insufficient controls of the distribution; 3) comparing rates of cultural turnover to tectonic environment; 4) mapping of trade-route propagation from senior complex cultures to active vs. quiescent nascent cultures, and 5) noting evolution of literature description of tectonic activity, and cultural response thereto, especially in Hebrew and Greek records. 
[v] I focused on the eastern hemisphere in all but one chapter.  Volcanism is a factor in the most complex ancient cultures there in only a few areas, e.g. central Italy.  Tsunami were not treated in any comprehensive way. 
[vi] Mass movements such as landslides, commonly triggered by seismic activity, can cause disasters also, sometimes via tsunami.
[vii] Ceremonial/religious sites were rebuilt especially tenaciously. 
[viii] Secondary effects of earthquakes include those modifying the land surface, such as changes in sedimentation rate modifying coastal morphology.  These may have important cultural consequences, perhaps best summarized by Bruce McFadgen and Manuel Berberian.
[ix] Andrew Robinson, Jelle de Boer, Kevin Rozario, and others.
[x] I note the work of Payson Sheets, Jelle de Boer, Richard Fisher, Mauro DiVito,  and Grant Heiken
[xi] Where volcanic ash cover is thin (the work of Mark Elson) or the composition inherently fertile (my own work in Italy).
[xii] Religious responses to volcanoes are commonly among the cultural responses in the historic period.  The work of Patricia Plunket and Gabriela Urunuela suggests these too have different structures from those to seismicity.  Volcano veneration and incantations etc. to avert volcanism continue into the modern period.
[xiii] Thucydides, Simon Winchester, Brian Atwater, and others.  Records of ancient tsunami are comparatively few in comparison to those of the historic and modern eras, but probably they were actually numerous—shown for example in the work of Gina Barnes.
[xiv] Such as the Nile delta (the work of Daniel Jean Stanley), or facing tectonic shores (Gina Barnes, Brian Atwater)
[xv] Especially Ruth Ludwin
[xvi] Wayne Howell and Bruce McFadgen.
[xvii] Wayne Howell. Oral traditions about tsunami continue into the modern era is some societies. 
[xviii] Gina Barnes and Bruce McFadgen
[xix] Especially Bruce McFadgen

Friday, May 6, 2016

Shakeup--Cultural impact of tectonic activity in ancient complex cultur

Shakeup—Cultural impacts of tectonic activity in ancient complex cultures
Eric R. Force

The following are the text and illustrations for recent talks I’ve given on this subject (see  acknowledgments).  For details and references see my book “Impact of tectonic activity on ancient civilizations” published by Lexington.  I think the talk format has values of its own, so am getting it more widely available.  I’ve also reordered the presentation from the book in order to emphasize the logic—an attempt to explore a “scientific method” for historical connections of this sort.

I’ll begin by telling you the conclusion I’ve come to, so the rest can be structured as evidence.  I think antiquity tells us pretty clearly that tectonic activity was a cultural stimulant in the long term, an agent of resilience and adaptation that resulted in greater cultural complexity.  This conclusion is of course counter-intuitive, so skepticism is quite understandable.    People tend to hang back on this, and so my logic has to be clear.  It consists of five parts:  spatial distribution, insufficiency of other factors, converse cases, kinetics, and dynamics. 

Tectonics and culture---I like to use an analogy with a very expensive exercise program, both taxing and costly but resulting in a kind of cultural athleticism.  Athletic tectonic communities have tended to lead the way in cultural development, and in so doing molded our cultural makeup.  It’s a significant part, I think, of how we got to where we are culturally. 

I’ve also found that when industrialization and technology are stripped away from our modern world, we can see that modern instincts are still the same as in the ancient world, and that our long-term responses to tectonic events follow the same paths.  So it’s wise to understand the dynamics at work here.

The spatial distribution data begin with figure 1, in which I have plotted the on-land tectonic plate boundaries of the eastern hemisphere and the originating sites of conventional “great ancient civilizations.” You may not like this term; I don’t either, but it does mean something in terms of cultural complexity.  I prefer to think of these as antiquities’ most athletic cultures. 


Figure 1.--Map locations of original sites of thirteen prominent ancient complex cultures of the Eastern Hemisphere relative to plate boundaries. Numbered cultures (and sites) are 1 Roman (Rome), 2 Etruscan (Tarquinia and Veii), 3 Greek (Corinth) and Mycenaean (Mycenae), 4 Minoan (Knossos-Phaestos), 5 and 6 SW Asian (Tyre and Jerusalem), 7 Assyrian (Ninevah), 8 Mesopotamian (Ur-Uruk), 9 Persian (Susa), 10 Indus (Mohenjo-Daro), 11 Aryan India (Hastinapura), 12 Egyptian (Memphis), and 13 Chinese (Zhengzhou). Dashed line represents the Altyn Tagh-Qinling escape structures. Straight lines are cultural/tectonic transects.

It’s a pretty amazing spatial correspondence, eh? The average distance from dot to line is only 125 km. The chance of this being random is one in several millions or even billions, depending on your assumptions.  I’ve varied the assumptions to provide sensitivity analyses.

Ancient China is a special case, quite consistent in one way because of the Altyn Tagh-Qinling escape structures shown dashed—plate boundaries in-process.  With that in mind, Egypt becomes the main probability outlier. 

The straight lines are transects across tectonic boundaries, shown in figure 2. Two transects are plotted here, one of them for two different periods of antiquity, centered on the southern boundary of the Eurasian plate (of fig. 1) and extending out about a thousand kilometers into tectonically quiescent territory, to give these transects a sort of continental scale.  On this horizontal axis the tectonic boundary is always plotted in the middle at zero no matter where the cross-section is taken. On the vertical axis is plotted cultural complexity as scored in the manner of Gordon Childe.    These are classic criteria for cultural complexity—rather common-sense ones I feel, like cities, specialization, monumental public architecture, record-keeping, arts, and trade. 


Figure 2.--Examples of continental-scale transects across some plate- tectonic boundaries showing cultural complexity in antiquity as quantified in terms listed by Gordon Childe. Superposed transects are normalized to approximate locations of plate boundaries; measurement relative to tectonic boundary is to originating site of each culture where known. Solid line is for western Asia in the 900-700 B.C. time period; dotted line is the same transect in the late Bronze Age. Lettered localities for that transect are: A, Assyria; B, Urartu; and C, Cimmerians and Scythians. The dashed transect is south Asia in the AD 400-600 period, with: D, Kalinga; E, Patna area of Guptan empire; and F, the Brahmaputra-Llasa valley of Tibet.

The point is that cultural complexity as measured by conventional criteria shows maxima near tectonic plate boundaries, where tectonic activity is greatest.  So the most complex cultures evolved just where seismic damage was most frequent. The results are not sensitive to exact position, nor to time period; I’ve tried other plots and they end up looking similar.

Clearly, tectonic activity did not hamper cultural complexity, strange as that might seem.  We should expect that this hemispheric distribution has corollary scenes at the scale of individual cultures, and I think we do--in several cases.  For this talk I’ll focus just on the Hellenic world.  Figure 3 is the back side of the Lions Gate at Mycenae—not a picture you see often—to show the slickensided young fault plane on the far side.  This particular fault clearly moved before construction of the gate, but others in the gorge behind the site moved during Mycenaean times and must have caused earthquakes. 

Figure 3.—Back side of Lions Gate at Mycenae, showing slickensided fault plane on other side.

Greece has several different types of tectonic boundaries, and each of them in antiquity had its own cultural history.  Figure 4 emphasizes the trend of Mycenaean palaces along the extension of the North Anatolian fault zone, a transcurrent fault analogous to the San Andreas fault of the western U.S.  In fact these palaces were destroyed by earthquakes along the zone.  So even at the scale of this individual ancient culture, a spatial correspondence of tectonism and cultural trends is apparent. 

Figure 4.--Ancient Mycenaean palace sites destroyed by earthquakes in 1200 or 1250 BC relative to approximate boundaries of distributed deformation along the projection of the North Anatolian fault (NAF) in the Hellenic realm. The distribution of destroyed Mycenaean palaces, with only a few exceptions, includes all the palaces of that civilization, suggesting not only ancient tectonic activity along this structural trend, but also the localization of Mycenaean civilization along it.. Localities: A, Athens; L, Lefkandi; C, Corinth; M, Mycenae; T, Troy; I, Iolkos (near Volos and Dimini).

Parenthetically, evidence like this of location and time of ancient seismic activity is an important ingredient in constructing maps of seismic risk today.  So you get geologists like me combing through ancient literature and excavation reports. 

Well, the spatial evidence of a connection between tectonism and cultural complexity looks strong—at several scales.  But how do we know that some other factor isn’t the REAL one here?  Something we knew all along, like climate, coasts, rivers, soil, water supply, or minerals.  And of course they ARE important; in general they are requisites for complex cultures.  I have to show that these other factors can’t work just as well as tectonism in producing the observed distributions. 

I find that these requisites constitute necessary but not sufficient factors to explain the spatial distribution. In other words, adding tectonism to the mix does the job, and no other factor or combination of factors does; they are insufficient.  Rather than recite my whole chapter 15, I think for this audience I’ll just pick one important factor as an example-- coastlines.  These are clearly important for trade connections in the ancient world.  If you look at figure 1 again, though, you’ll see that not all Mediterranean or Black Sea shores were equally propitious.  The complex cultures tended to follow the tectonically active shore. I’ve done probability calculations of several sorts on this as well as the other requisite factors.   They show that adding tectonic position greatly improves the correlation in every case.  That is, both tectonics and the requisites are needed to provide both necessary and sufficient conditions.

You may also notice in figure 1 that derivative complex cultures as opposed to the primary hydraulic ones (Egypt, Mesopotamia, Indus, China) show the closest spatial relation to tectonic boundaries.  This suggests a role of trade. The work of Nicholas Coldstream helped to reconstruct incremental snapshots of trade propagation in the Mediterranean in the Greek Geometric period (figure 5).  Note that this propagation mimics the shape of the tectonic southern boundary of the Eurasian plate, on both land and sea (fig. 1)—even the double-catena shape in the eastern Mediterranean.  Stone anchor distribution verifies these island-hopping routes.  Derivative civilizations (Phoenicia to Greece to Etruscan, for example) tend to originate along the tectonic trade routes.  That’s a clue to the kinetics of the relation.

Figure 5.--Map of progressive trade-route extension from Phoenicia, then Greece in the Geometric period (900-700 BC). Symbols: I refers to trade in Early Geometric I, II to Early Geometric II, and III to Middle Geometric—each shown as additional routes (the preceding ones still active).

It appears that tectonic-boundary cultures are most responsive to influences of trade.  In contrast, trade routes that project into tectonically quiescent cratonic interiors do not spawn super-complex cultures. In fact the ages of ancient cultures in some such places are defined by trade goods that originate in tectonic-boundary cultures. 

This in turn implies that tectonically quiescent cultures were more static.  There must be a better way to look into that, but figure 6 is what I did.  If I use as a metric the length of time that a complex culture remains essentially the same, there is a fairly clear relation to tectonic environment. The cultures that remain the same for thousands of years tend to be farther from tectonic boundaries.  Thus the main converse case is covered; tectonic-boundary cultures are systematically more dynamic.  Perhaps their complexities arose as a result.

Figure 6.--Semi-logarithmic plot of the duration of ancient complex cultures plotted against the approximate distance between originating sites and tectonic boundaries.  Numbered cultures are: 1, Carthaginian; 2, Etruscan; 3, Roman; 4, Mycenaean; 5, Greek; 6, Minoan; 7, Trojan; 8, Hittite; 9, Phoenician; 10, Hebrew; 11, Assyrian; 12, southern Mesopotamian; 13, Achaemenid Persian; 14, Indus-Saraswati; 15, Aryan Indian; 16, Egyptian; 17, Chinese (shown two ways).

By now we’ve seen a remarkable spatial correspondence of ancient cultural complexity and tectonic activity, I’ve shown that other factors don’t do the job, and we’ve seen that trade propagation versus cultural stasis are involved.  In other words we have evidence from distribution, necessity versus sufficiency, a converse case, and kinetics linking cultural complexity and tectonic activity. But how does it actually work; what are the cultural dynamics? 

A few of the clues can come from archaeology. Klaus Kilian presented a chronology of destruction levels at Mycenaean Tiryns (figure 7), three out of four corresponding with a new pottery style (or three out of five styles corresponding with destruction levels).   Well, such ceramic punctuation occurs with modern earthquakes, too -- all the broken pots are replaced with the current style. The cultural implications are modest, but do imply great tenacity in inhabiting a favored site despite the need to rebuild.  We see the tenacity theme repeated again and again. 

Figure 7.—Seismic destruction levels plotted against abundance of new pottery styles at Mycenaean Tiryns.

We can also see an evolution of methods to make continued occupancy possible (figure 8).  These dog-bone-shaped slots accommodated bronze keys wrapped in lead to impart both strength and cushioning between blocks. 

Figure 8.--Photo of “antiseismic devices”, i.e., channels in stone foundations and column drums, in order to accept dog-bone-shaped bronze pins, wrapped in lead, that link two stone blocks. The example shown here is from Hadrian’s library in Athens.  Examples earlier than about 400 BC had more rudimentary devices.

How do we know what these discontinuities mean in cultural terms?  At some sites we know more about, we see tenacity recorded in historic context.  Figure 9 is Delphi, showing architecture before (Archaic wall below) and after (temple ruins above) the 373 BC earthquake.  For this we have a voluminous literature with several tectonic chapters.

Figure 9.—Archaic foundation of the Temple of Apollo at Delphi, surmounted by Doric columns of a younger temple built atop these foundations after the earthquake of ca. 373 B.C.  The younger temple was itself damaged by an earthquake of ca. 86 B.C.  Delphi is at an intersection of NAf and Corinth-rift faults (fig. 4).

Ancient literature can clarify how cultures dealt with earthquakes, and two cultures have voluminous literatures on the subject.  Greek mythology and literature is full of earthquakes—Aeschulus, Herodotus, Thucydides, Euripides, Aristotle, and many Greeks of the Roman era.  Several thought earthquakes were important in cultural evolution—Herodotus and Thucydides each had a favorite earthquake to divide Greek history into segments, but picked different ones.  Thanks to the Greek drive to understand nature, we see an evolution in their history from Poseidon fitfully causing earthquakes, eventually to Thucydides giving an essentially modern explanation of how tsunami work (figure 10).

•  “The cause in my opinion of this phenomenon must be sought in the earthquake.  At the point where its shock has been the most violent, the sea is driven back, and suddenly recoiling with redoubled force, causes the inundation.”
Figure 10.—Thucydides on tsunami (from his History III (xi) 89)

The record of earthquakes in Hebrew literature is even more striking.   The bible records its own evolution of earthquake description, eventually of manipulation by zealous prophets threatening the next earthquake if people don’t take the next step of reform.  Zechariah, seemingly the smartest one, craftily forecasted the correct sense of ground motion for the local boundary between African and Arabian plates (figure 11). But even this is not in terms of natural process, and it’s the only Biblical passage I’ve found that’s even vaguely scientific.  Overall, the prophets racheted observance toward the God-FEARING religion we can still find in Judeo-Christian traditions. A sort of cultural evolution, I suppose.

•And (the Lord’s) feet shall stand that day upon the Mount of Olives . . . And it shall cleave in the midst thereof . . .  And half of the mountain  shall remove toward the north, and half of it toward the south.
Figure 11.—Zechariah 14: 4-5 (KJV)

Both the Greeks and Hebrews show us the deep roots of tectonism in their cultures, and an evolution in how those roots took hold. But here’s another way to look at it: these same two cultures that provide the most literature evidence are also those that most influenced our modern western culture.  So in some ways we inherit tectonically-molded attitudes.

The modern world would seem to have little resemblance to these ancient responses.  But the economic literature has focused on recovery from seismic events in our world, and to lesser extents the philosophical and psychological literatures have too.  Several modern political upheavals were catalyzed by tectonic activity, and sometimes these look remarkably similar to those in the ancient world—compare Sandinistas to Spartan helots, both breaking off with an earthquake.    Religious responses have also been common in both the modern and ancient worlds.  These too can look remarkably similar—compare Pat Robertson to Jeremiah or Zechariah.

So the behavior of our world does give some clues to responses to tectonism in the ancient world.   No-one would dispute that in the modern world the responses are cultural.  It’s not a pretty sight to individual victims, of course.  That’s probably why so many of the upbeat descriptions are by economists, not anthropologists.

In the modern world a lot of this response takes a different path, along plate margins around the Pacific--and not just California and Japan (figure 12).

Figure 12.—New Zealand Herald, Mar. 2014 (three years after Christchurch earthquake)

Literature vignettes and modern evidence do flesh out the distribution and kinetic information, and help us see what the links look like.  The dynamics they suggest take the shape of an evolution of responses to change.

There seem to be different types of cultural response with different tectonic environments.  Figure 13 is a simplistic cross-section of a typical subduction-type convergent tectonic boundary. For the culture on the left, the response is to seismicity, whereas to one in the middle it is a mostly a response to volcanism.  For the culture to the right, there is no response; they do everything just like they always did.

Figure 13.--Diagram of converging tectonic plates showing subduction, melting, and volcanism, along with apparent cultural tendencies in antiquity. Site A is most seismically active, site B is mostly volcanic, and site C is quiescent.

The guy on the left sometimes has earthquake gods, whereas the guy in the middle has volcano gods. In such cases two tracks of response (projecting into the diagram), especially religious response, can be recognized along the same tectonic boundary.  But this diagram is just a simplistic view of one type of tectonic boundary. 

An aside—the guy on the left may be drinking an anomalous water, especially if the dip of the tectonic boundary is steep.  Faults that penetrate the whole crust of the earth carry water with anomalous isotope values in their voluminous springs. If the difference is preserved in skeletal material, we could begin to quantify tectonic effects.
We’ve now seen several lines of evidence that connections between tectonic activity and cultural complexity were direct, and basically cultural.  I’ve tried to come at the question from several independent angles.  Starting with the modern world where we can see that the responses to tectonism are cultural; in the ancient world stasis vs. dynamism is a cultural contrast; trade was driven by cultural imperatives; the ancient literary descriptions are in cultural terms; and of course the transect geometries are culturally defined.  

Exactly what is the pertinent cultural factor?  The most obvious one is that tectonism forces the pace of change, eventually resulting in a culture with built-in resilience.  We’ve actually seen this in ancient literature, architecture, and receptivity to trade.   We can expect that tectonic-village elders would not be telling their youngsters that old ways are best, like they do elsewhere, but to be prepared for change.  There is a tendency for tectonic communities to be dynamic—or athletic—or environmental opportunists.

I suspect that the relation of event recurrence interval to generational succession produces a threshold factor.  In other words if event recurrence is too long, people will have forgotten (figure 14). Where recurrence is longer than two generations, elders who remember have passed on. This might be especially so in pre-literate societies. I speculate that short recurrence intervals best correspond to accelerated change.

•“Natural calamity strikes at about the time when one forgets its terror” 
Figure 14.—Traditional Japanese proverb

I also wonder whether tectonic communities are systematically different from quiescent communities, whether or not they qualify as great civilizations.  This seems a promising avenue for anthropological research.

So it looks like tectonism has helped to mold our cultural makeup. Realizing this should be useful in new ways-- dealing with long-term aspects of disaster recovery for example.  Archaeologists address the subject via the field of archaeoseismology but anthropology has generally focused only on short term responses--except to volcanism and tsunami.

Incidentally, there’s evidence from earlier periods in hominid history that implicates tectonism--along with other factors.  So earth’s basic machinery has been a factor in both our physical and cultural development, and still is to some degree in our own complex culture.

The logic behind my presentation here consists first in showing that tectonism is necessary for a complete explanation of the spatial distribution, then that the converse case looks very different, then that we can see this unfold kinetically, and last that several ways of looking at the dynamics show us that the relation to tectonism is cultural, and has to do with response to change. This suggests new ways of looking at antiquity, and at the modern world through the evidence from antiquity.

I think the logic is pretty tight considering these historical connections are untestable in the strict sense. There are more aspects of my hypothesis that are indirectly testable--I’m doing one such test now, and I’d like suggestions for others. But in the meantime it looks like tectonism accelerated change in some ancient cultures, and those were the ones that systematically contributed far more than quiescent cultures in leading the way into our own cultural trajectory.

Acknowledgements—The talks on which this manuscript is based were delivered at the American Institute of Archaeology in Tucson AZ, Feb. 2016, and the Society for Applied Anthropology in Vancouver BC, Apr. 2016.  The time for delivering the former was far greater, and this manuscript generally follows its format.  References documenting illustrations and text appear in my book.