Dimension anthropique de l'éruption du Mont Pinatubo, Philippines, entre 800 et 500 ans BP

Before its worldwide famous awakening in 1991, Mt Pinatubo volcano erupted between 800 and 500 year BP. The impacts of this little known eruption are progressively coming to light with the discovery of archaeological sites and the study of oral and geographical records. Recent archaeological excavations have shown that pyroclastic flows and lahar onslaughts have probably led to the abandonment of major settlements on both sides of Mt. Pinatubo. The location of these archaeological sites and the toponyms on the east flanks of the volcano suggest a general redistribution of the population downstream toward lands reclaimed on the sea due to heavy lahar material deposition. These population movements did not occur on the west side of the mountain despite similar land reclamation. Such topographic and socio-demographic changes have deeply disturbed the economic environment since it is hypothesized that extensive trade with China and other foreign “countries” profited from the easy penetration of commercial vessels into the bays that would have been filled up by lahar deposits. Finally oral memory records, such as legends and epics, help define the ethnic groups that have suffered from the eruption (e.g. Aetas, Kapampangans and Sambals). Understanding what happened 500 years ago turns very useful to anticipate the consequences of future events.