3,800 years ago, a 9.5-magnitude earthquake triggered a massive tsunami destructive to the coast of Chile. Prehistoric people had taken refuge inland, preserving the memory of this catastrophe for nearly 1,000 years.
The western coast of South America, due to its position in convergent plate boundaries, is at high seismic risk. every yearwhich sees the oceanic Nazca plate sinking under the South American continental plate is indeed responsible for many earthquakes, some of which can be very strong. It was recorded off the coast of Chile in 1960. this earthquake caused a rise A circumference of six meters in some places, causing a violent tsunami. Waves 10 to 12 meters high swept the Chilean coast, sweeping away everything in its path and killing 3,000-6,000 people.
A tsunami is sure to be very deadly for the prehistoric people who live on the coast
However, this tectonic context is not recent and has presented significantly. It is possible that such seismic events, of somewhat similar amplitude, have already occurred in the past. A team of researchers also provides evidence that a huge tsunami struck the Chilean coast about 3800 years ago. The results of the study were published in , indicates that the strength of the earthquake at the origin of this tsunami must be similar to that of 1960. However, at that time, Chile was already occupied by groups of fishermen – gatherers – fishermen who lived along the coast. Extremely vulnerable situation in the event of a tsunami. Scientists also showed that after this catastrophic event, the population had deserted the coast to settle within . This situation could have lasted about 1000 years, indicating a long-term transmission of history with a capacity Importance.
To reach these conclusions, scientists conducted geological and archaeological excavations. Geological research focused on sedimentary deposits left by the tsunami. History of shells and shrapnel He was allowed to fix this event around the year -1778. Deposit site as well From the tsunami made it possible to estimate earthquake in mw 9.5 This would have generated a devastating wave 15 to 20 meters high. It is easy to imagine the disastrous impact this tsunami had on the coastal population. Signs of destruction were also observed at many archaeological sites on the coast.
The memory of the disaster has been passed down for nearly 1,000 years
This event marks a major turning point in the organization of the prehistoric societies inhabiting this region, including the massive transformation of the interior or higher regions. The most impressive result is that these inhabitants did not return to live on the coast for 1,000 years. This observation shows that the memory of the tsunami has been passed down from generation to generation, over a period of about a thousand years. We also note that in the long term, the resettlement of the population was carried out in a more cautious manner, with the development of housing sites far from the coast or at elevations, at an altitude of at least 20 meters above sea level. The sea, which surprisingly corresponds to the maximum tsunami wave that occurred 1,000 years ago. In what way was this memory of danger conveyed? Scientists do not know. It is certainly oral history, these societies do not yet have a written language.
These findings provide a better understanding of the evolution of the population in this region of the world and their resilience and resilience in the face of a natural disaster of this type. They should also make it possible to better define the risks to the Chilean coasts, which are currently densely populated.