​The Azores archipelago is located at the triple junction between the Eurasian, Nubian and North American lithospheric plates, whose boundaries are the Mid-Atlantic Ridge and the Azores-Gibraltar Fault Zone. São Miguel is the largest island of the archipelago and is located on the eastern part of the western segment of the Azores-Gibraltar Fault Zone. The Achada das Furnas plateau, located in the central part of the island, between Fogo and Furnas central volcanoes, is dominated by sev- eral WNW-ESE and E-W trending alignments of basaltic cinder cones. Two E-W trending scarps were identified by aerial photo interpretation. Transect trenches exposed two active normal faults-the Altiprado Faults – confirming the tectonic nature of the scarps. Several paleoearthquakes were deduced, most of which in historical times, producing 1.38 m and 0.48 m of cumulative displacement. Maximum expected magnitudes (MW) determined from slip per event range from 5.7 to 6.7. One of the events probably corresponds to the historical earthquake of October 22^nd, 1522, the deadliest in the archipelago. Radiocarbon ages are in agree- ment with this interpretation.