Morphotectonic features reveal recent seismic activity on normal faults on Crete allowing slip-rates, palaeoearthquake magnitudes and earthquake recurrence intervals to be inferred. The studied faults show major escarpments (100s m high, 10s km long), separating uplifted Mesozoic rocks from Quaternary deposits. During Holocene, slip-rates out-paced erosion/sedimentation rates and 5-15 m high fresh scarps formed at the base of the major escarpments. Based on our field observations and following empirical relationships between magnitude, surface rupture length and maximum co-seismic vertical displacement, it was possible to infer all principal seismotectonic parameters for the investigated faults. Long-term throw-rates range between 0.4 and 1.2 mm/a, maximum expected magnitudes between 6.3 and 6.6 (or 6.6-6.9, considering the worst case scenario), while mean recurrence intervals range between >200 and 1000 years. These estimates are in good agreement with the historical and instrumental seismicity allowing to improve seismic hazard estimates in Crete.
Multi-seismic cycle deformation rates from Holocene normal fault scarps on Crete (Greece).
CAPUTO, Riccardo;
2006
Abstract
Morphotectonic features reveal recent seismic activity on normal faults on Crete allowing slip-rates, palaeoearthquake magnitudes and earthquake recurrence intervals to be inferred. The studied faults show major escarpments (100s m high, 10s km long), separating uplifted Mesozoic rocks from Quaternary deposits. During Holocene, slip-rates out-paced erosion/sedimentation rates and 5-15 m high fresh scarps formed at the base of the major escarpments. Based on our field observations and following empirical relationships between magnitude, surface rupture length and maximum co-seismic vertical displacement, it was possible to infer all principal seismotectonic parameters for the investigated faults. Long-term throw-rates range between 0.4 and 1.2 mm/a, maximum expected magnitudes between 6.3 and 6.6 (or 6.6-6.9, considering the worst case scenario), while mean recurrence intervals range between >200 and 1000 years. These estimates are in good agreement with the historical and instrumental seismicity allowing to improve seismic hazard estimates in Crete.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
