For decades, archaeologists were convinced that large earthquakes destroyed the great palaces of the Mycenaean civilization in the Peloponnese around 1200 BCE. But new research and studies of the Earthquake Hypothesis conclude that it is unlikely that seismic activity would have contributed to the fall of Mycenae.
In the 1980s several findings in the most recent archaeological excavations at Mycenaean Tiryns in the Argive Basin, Peloponnese, led the excavator to interpret undulating and inclined walls, fallen pottery, and human remains as signs of a devastating earthquake that destroyed the palatial buildings and other constructions within the Tiryns citadel. It was even speculated that this natural disaster dated to 1200 to 1190 BCE could have been a contributing cause for the decline of the Mycenaean civilization, and later by others that this event was part of a 50-years-lasting ‘earthquake storm’ in the Eastern Mediterranean.
In a comprehensive, a team of
scientists collected new geophysical data at the archaeological World Heritage site of Tiryns and its surroundings to study local earthquake site effects.
To test the Mycenaean earthquake hypothesis, this project focused on the Argive citadels of Tiryns and Midea.
wikipedia commons
Tiryns a Mycenaean archaeological site in Argolis in the Peloponnese, 12 kilometres north of Nafplio. It was a hill fort with occupation ranging back seven thousand years, from before the beginning of the Bronze Age. It reached its height between 1400 and 1200 BCE, when it was one of the most important centers of the Mycenaean world, and in particular in Argolis. Its most notable features were its palace, its cyclopean tunnels and especially its walls, which gave the city its Homeric epithet of “mighty walled Tiryns”.
In 1300 BCE the citadel and lower town had a population of 10,000 people covering 20-25 hectares. Despite the destruction of the palace in 1200 BCE the city population continued the increase and by 1150 BCE it had a population of 15,000 people.
In ancient times, the city was linked to the myths surrounding Heracles, with some sources citing it as his birthplace.
Tiryns was recognized as one of the World Heritage Sites in 1999.
With active and passive seismic measurements complemented by a gravimetric survey, the scientists explored seismic site effects at these locations and calculated synthetic seismograms for potential earthquake sources to estimate intensities of ground motions inside and outside the citadels.
The scientists reviewed the archaeological evidence and excavation photos, used laser scans to further explore damage patterns in constructions including the massive Cyclopean fortification walls. P- and S-wave refraction tomography, HVSR single station measurements and noise recordings with 10-station arrays allowed to model the site effects and compare these with standard spectral ratios of onsite recorded local earthquakes.
While the shallow double limestone knoll of Tiryns, which contained the Mycenaean palace and carries a massive Cyclopean fortification wall, shows only small site amplifications below a factor of 2 at frequencies between 2 and 10 Hz, the soft sediments in the surrounding area, where the peasant residences were located, show amplifications of 4 to 6.
However, no earthquake damage in the Lower Town has been archaeologically documented so far.
Synthetic site specific seismograms for earthquake scenarios including sources at the Hellenic subduction zone and the Patras-Corinth rifting zone do not support the earthquake hypothesis and a reactivation of local faults of the Argolis is doubtful.
Several aspects of the previously presented ‘earthquake evidence’ could be shown to be erroneous or not compatible with quantitative modeling, as in case of the fallen pottery and earthquake induced fatalities. Some of the described damage can be well explained with natural decay processes such as earth pressure and weathering by root pressure.
It is clear that the site has been shaken by several earthquakes in its 3500 years of history; however, it is unlikely that a devastating earthquake destroyed the Mycenaean structures at Tiryns around 1200 BCE.
- Observations at Mycenaean archaeological sites of tilted and curved walls, broken pottery, and human skeletons led to the hypothesis that these sites in the Argolid, Peloponnese, Greece, were destroyed in large earthquakes between the late palatial (thirteenth century B.C.E.) and postpalatial (1200–1050 B.C.E.) periods.
The field work and results were supplemented by analysis of the individual damage descriptions and observations from the archaeological literature on which the hypothesis is based. Because of poor construction techniques and the associated site effects, the buildings in the Lower Town surrounding the citadel of Tiryns were more vulnerable than the structures within the Cyclopean palace walls, but evidence of an earthquake destruction stratum in the Lower Town has not yet been found.
Although some of the observations from the two investigated citadels could be explained by seismic loading, alternative nonseismic causes could equally explain most observed damage.
- In some cases, the structural damage was clearly not caused by earthquakes.
Simulated ground motions show that severe earthquake damage at Tiryns and Midea can be expected from activation of local faults in the Argive basin; however, palaeoseismic studies for such activity in and since the Late Bronze Age (LBA) are lacking.
The study results indicate that the hypothesis of a destructive earthquake in Tiryns and Midea, which may have contributed to the end of the LBA Mycenaean palatial period, is unlikely.
Study excerpt also here
Tiryns, Midea (Argolid)
