Paleoseismological analyses have been performed along the Campo Imperatore fault (part of the Gran Sasso Range fault system) in order to define the seismogenic behaviour (recurrence interval for surface faulting events, elapsed time since the last activation, maximum expected magnitude). Four trenches were excavated across secondary faults which are related to the main fault zone. The youngest event (E1) occurred after 3480-3400 yr. BP; a previous event (E2) occurred between 7155-7120/7035-6790 yr. BP and 5590-5565/5545-5475 yr. BP, while the oldest one (E3) has a Late Pleistocene age. The chronological interval between the last two displacement events ranges between 1,995 and 6,405 years. The minimum elapsed time since the last activation is 800 years, due to the absence of historical earthquakes which may have been caused by the Campo Imperatore fault and based on the completeness of the historical catalogues for the large magnitude events in the last eight centuries. Based on the length of the fault surficial expression, earthquakes with M 6.95 may be expected from the activation of the entire Gran Sasso Range fault system. The effects of the fault activation were investigated through the simulation of a damage scenario obtained by means of the FaCES computer code, made by the National Seismic Survey for civil protection purposes. The damage scenario shows that the activation of the Gran Sasso Range fault system may be responsible for an earthquake with epicentral intensity Io 10.5 MCS, with a number of collapsed buildings ranging between 7,900 and 31,100 and a number of damaged buildings ranging between 99,000 and 234,000. The investigated case defines, therefore, a high risk level for the region affected by the Campo Imperatore fault.
Paleoseismology of silent faults in the central Apennines (Italy): the Campo Imperatore fault (Gran Sasso Range Fault System).
2003
Abstract
Paleoseismological analyses have been performed along the Campo Imperatore fault (part of the Gran Sasso Range fault system) in order to define the seismogenic behaviour (recurrence interval for surface faulting events, elapsed time since the last activation, maximum expected magnitude). Four trenches were excavated across secondary faults which are related to the main fault zone. The youngest event (E1) occurred after 3480-3400 yr. BP; a previous event (E2) occurred between 7155-7120/7035-6790 yr. BP and 5590-5565/5545-5475 yr. BP, while the oldest one (E3) has a Late Pleistocene age. The chronological interval between the last two displacement events ranges between 1,995 and 6,405 years. The minimum elapsed time since the last activation is 800 years, due to the absence of historical earthquakes which may have been caused by the Campo Imperatore fault and based on the completeness of the historical catalogues for the large magnitude events in the last eight centuries. Based on the length of the fault surficial expression, earthquakes with M 6.95 may be expected from the activation of the entire Gran Sasso Range fault system. The effects of the fault activation were investigated through the simulation of a damage scenario obtained by means of the FaCES computer code, made by the National Seismic Survey for civil protection purposes. The damage scenario shows that the activation of the Gran Sasso Range fault system may be responsible for an earthquake with epicentral intensity Io 10.5 MCS, with a number of collapsed buildings ranging between 7,900 and 31,100 and a number of damaged buildings ranging between 99,000 and 234,000. The investigated case defines, therefore, a high risk level for the region affected by the Campo Imperatore fault.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
