Felt index, source parameters and ground motion evaluation for earthquakes at Mt. Vesuvius

Abstract

Results of non-instrumental surveys carried out on recent and past seismicity at Vesuvius have been retaken in order to propose new analyses regarding source mechanisms and causative faults. We present the results of the October 9, 1999, earthquake, the most intense event since the 1944 eruption. The intensity was evaluated by utilizing integer values of the MCS Scale and the felt index as a continuous parameter. Values of magnitude and attenuation determinated by applying macroseismic models to data, and compared to instrumental ones, were utilized to assess the “size” of the historical Vesuvian earthquakes. A magnitude of M = 5.1±.3 was considered for the A.D. 62 earthquake, the largest one of the area that preceded the A.D. 79 famous eruption. By using the macroseismic field of October 9, 1999, the source mechanism of the earthquake was obtained, and synthetic isoseisms and causative fault of the A.D. 62 are also proposed.

Keywords

• Vesuvius
• Felt index
• Earthquake intensity
• Source parameters
• Ground motion