Downlift

This is explained as an uplift in the coast at a rate of 16.2 mm/y in the period before 1900, a downlift of 2.8 mm/y in the period 1900-1906 and a rapid «sinking» of the coast at 22.7 mm/y in the 24 months before the earthquake.

The structure's magma chamber remains active as there apparently are solfataras, hot springs, gas emissions and frequent episodes of large-scale up- and downlift ground deformation (Bradyseism) do occur.