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.
