Contenu du sommaire : Quand la terre tremble : apprivoiser le choc des séismes dans les temps anciens

In ancient Greece, earthquakes seem to fall under two irreconcilable types of explanation : either as a manifestation of the anger of the god Poseidon, or as a purely natural phenomenon due to the excessive accumulation of an underground element – water, air or breath (pneuma). But this apparent opposition conceals conceptual analogies. Poseidon's action is not simply destructive. It participates in the construction of a habitable world by organising the circulation of water. Naturalist theories are based on the same idea that the earthquake, just like bodily disorders, reflects an imbalance in the circulation of a primordial principle. « Belief » and « science » are based on the same representations ; it is in the relationship between cause and effect that they diverge.

If the sound of the earthquake that struck Nicomedia on August 24, 358 has reached us, it is thanks to the words of those who recounted it, each in a different genre : the historian Ammianus Marcellinus, the rhetorician Libanius and the poet and theologian Ephrem of Nisibis, who are rarely placed side by side. None of the three was present at the scene, but each of them tried to capture the emotions aroused by the catastrophe, and in turn to arouse the emotions of their audience through the power of rhetoric. They spun tenuous explanatory threads to understand the links between the gods (single God of the Christians or multiple gods of traditional religions) and telluric tremors and water movements.

Antioch on the Orontes has been hit by numerous earthquakes throughout its history. Nearly twenty have been recorded in Antiquity. The first stage of the research is to draw up a list of these earthquakes, based on a critical analysis of existing studies. It is difficult to accurately assess their real demographic and material consequences, even in the few cases where sources provide figures. On the other hand, the texts clearly highlight the importance of these traumatic events in the construction of a historiographical discourse on the city and in the perception of its destiny and identity, to the point of changing its name from Antioch (the city of Antiochus, founded under the leadership of Zeus) to Theoupolis (the city of God).

The cuneiform textual tradition, which dates from the middle of the third millennium BC, provides only rare evidence of earthquakes in the Syro-Mesopotamian world, although they must have occurred frequently. Conversely, documents from the state archives of the Neo-Assyrian Empire (7 th century BC) discuss earthquakes, seen primarily as signs communicated by the gods to the king, announcing his fate and that of the state. The king could then have specialists perform the rites necessary to avert the crisis.

Ever since the emergence of Islam, earthquakes have been considered, first as the result of divine will, and then, under the influence of Greek sciences, as the effect of a profane physical mechanism. In the first case, since created nature is the work of the Creator, it is not difficult to imagine that he uses it as an instrument, but for what purpose ? The earthquake thus appears to have several meanings : it foretells, accompanies or warns of an event of universal significance, but it also punishes moral faults. In practice, the medieval Muslim imagination views this divine intervention through two distinct cosmologies, each of them being syncretic since they bring together earlier mythical elements, such as Mount Qāf on the one hand, and the angel, the bull and the whale on the other. As for the “mechanistic” perspective, it employs the Aristotelian theory of terrestrial exhalations to justify the shaking of the ground in specific places, in an interplay of thrust and resistance driven by heat.

While the earthquake is primarily a cosmogonic act provoked by the intrusion of Evil into Ohrmazd's world, the Zoroastrian accounts describing the phenomenon also bear witness to a striking confluence of myth, mechanistic theories and biological analogies. The tradition conveyed by the texts (Bundahišn 21e, Dēnkard III.93 and Dādestān ī Dēnīg 69) attributes the earthquake sometimes to the demon Čišmag and his atmospheric acolytes, sometimes to the sorcerer Frāsyāb, two figures who also have in common that they are associated with drought. Some episodes featuring them also include a mysterious appearance by Spandarmad, the Earth goddess. These elements indicate that the Zoroastrian aetiology of earthquakes was far more narratively complex than the texts handed down to us give us to understand.

Abundant as they may be in the literary sources of Indian Buddhism, earthquakes are hardly reducible to “catastrophic” events of a purely natural and historical character. Rather, they have to be read against a “hiero-historical” background as signs celebrating the main events in the biography of a (future) Buddha, manifesting the superior psychic powers of certain beings (monks/nuns, deities), or marking the approval of the (goddess) Earth. The salvific intention behind them explains why they are perceived, if not always as pleasant, at least as not causing casualties or damage in spite of their at times terrifying nature. This interpretation, though largely dominant, coexists with various astrological and seismomantic uses of earthquakes.

This article looks at how earthquakes were explained and used as a basis for predictions in seventeenth- and early eighteenth-century Japan. During this period, which corresponds to the first third of the Edo period 江戸 (1603-1868), earthquakes were presented as phenomena that could be explained by various theories. Some of these relied upon “physical”principles derived from Confucian, Buddhist and even Aristotelian cosmologies, while others were grounded on mythical accounts featuring local gods. Furthermore, earthquakes continued to be considered as a form of omen, and as such could be subject to predictive techniques. By looking at the intersections between these two seismological approaches, we will see how cosmology is linked to moral considerations, and natural phenomena to human destiny.