Italy’s long history affords a unique record of earthquake occurrence, which is invaluable for earthquake forecasts. The left panel shows the highest shaking observed since A.D. 1600, from Azzaro et al. (2013a). The right panel shows the most probable peak shaking for the next 20 years, also from Azzaro et al. (2013a). This forecast is consistent with the Christmas quake.

Italy's long history affords a unique record of earthquake occurrence, which is invaluable for earthquake forecasts. The left panel shows the highest shaking observed since A.D. 1600, from Azzaro et al. (2013a). The right panel shows the most probable peak shaking for the next 20 years, also from Azzaro et al. (2013a). This forecast is consistent with the Christmas quake.

Italy’s long history affords a unique record of earthquake occurrence, which is invaluable for earthquake forecasts. The left panel shows the highest shaking observed since A.D. 1600, from Azzaro et al. (2013a). The right panel shows the most probable peak shaking for the next 20 years, also from Azzaro et al. (2013a). This forecast is consistent with the Christmas quake.