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A three‐dimensional Q P imaging of the shallowest subsurface of Campi Flegrei offshore caldera, southern Italy
Author(s) -
Serlenga Vincenzo,
Lorenzo Salvatore,
Russo Guido,
Amoroso Ortensia,
Garambois Stephane,
Virieux Jean,
Zollo Aldo
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl071140
Subject(s) - caldera , fumarole , geology , volcano , seismology , submarine pipeline , impact crater , petrology , mineralogy , physics , geotechnical engineering , astronomy
To improve the knowledge of the shallowest subsurface of Campi Flegrei caldera, a 3‐D P wave attenuation tomography of the area was performed. We analyzed about 18,000 active seismic traces, which provided a data set of 11,873 Δ t * measurements, e.g., the differential travel times to quality factor ratios. These were inverted through an adapted tomographic inversion procedure. The 3‐D tomographic images reveal an average Q P about 70, interpreted as water‐saturated volcanic and marine sediments. An arc‐like, low‐ Q P structure at 0.5–1 km depths was interpreted as a densely fractured, fluid‐saturated rock volume, well matching the buried rim of Campi Flegrei caldera. The spatial distribution of high‐ and low‐ Q P bodies in the inner caldera is correlated with low‐ V p values and may reflect either the differences in the percentage of fluid saturation of sediments or the presence of vapor state fluids beneath fumarole manifestations.