%0 Journal Article %1 aster_meyer:1988 %A Aster, R. C. %A Meyer, R. P. %D 1988 %J Tectonophysics %K geophysics seismology %N 3-4 %P 195--218 %R 10.1016/0040-1951(88)90173-4 %T Three-dimensional velocity structure and hypocenter distribution in the Campi Flegrei caldera, Italy %U http://dx.doi.org/10.1016/0040-1951(88)90173-4 %V 149 %X The Campi Flegrei (Phlegraean Fields) are dominated by a Quaternary explosive calders, about 10 km in diameter. Within the caldera are numerous later eruptive vents, the last of which formed in 1538 A.D. Well documented local elevation changes of 10 m have occurred in the caldera since Roman times. Recent inflation of the central caldera began in 1968, after over 400 years of subsidence. During this time more than 2 m of localized uplift occurred, predominantly from 1980 through 1985. Microearthquakes associated with this uplift were recorded by a portable three-component digital network deployed by the University of Wisconsin and the Vesuvius Observatory from August 1983 through May 1984. Those data have been used to obtain detailed information about the velocity structure of the caldera. A best-fit homogeneous half-space model was obtained by a systematic search for optimal residual statistics. A residual-based tomographic technique was applied to isolate a low-seismicity, anomalously-high vp/vs region in the central caldera, roughly coincident with the region of greatest uplift. Finally, P and S arrival times were used to simultaneously relocate 228 earthquakes and obtain a three-dimensional vp and vs model for the caldera. The results of this velocity study, considered along with drillhole findings, composite fault-plane solutions, and the space-time distribution of earthquakes, suggest that the vp/vs anomaly may represent an incompetent, highly fractured volume, saturated with liquid water. Hypocenter locations indicate a zone of concentrated seismicity north of the point of highest measured uplift. An inward-dipping elliptical hypocenter pattern suggests a ring fault.

@article{aster_meyer:1988, abstract = {The Campi Flegrei (Phlegraean Fields) are dominated by a Quaternary explosive calders, about 10 km in diameter. Within the caldera are numerous later eruptive vents, the last of which formed in 1538 A.D. Well documented local elevation changes of 10 m have occurred in the caldera since Roman times. Recent inflation of the central caldera began in 1968, after over 400 years of subsidence. During this time more than 2 m of localized uplift occurred, predominantly from 1980 through 1985. Microearthquakes associated with this uplift were recorded by a portable three-component digital network deployed by the University of Wisconsin and the Vesuvius Observatory from August 1983 through May 1984. Those data have been used to obtain detailed information about the velocity structure of the caldera. A best-fit homogeneous half-space model was obtained by a systematic search for optimal residual statistics. A residual-based tomographic technique was applied to isolate a low-seismicity, anomalously-high vp/vs region in the central caldera, roughly coincident with the region of greatest uplift. Finally, P and S arrival times were used to simultaneously relocate 228 earthquakes and obtain a three-dimensional vp and vs model for the caldera. The results of this velocity study, considered along with drillhole findings, composite fault-plane solutions, and the space-time distribution of earthquakes, suggest that the vp/vs anomaly may represent an incompetent, highly fractured volume, saturated with liquid water. Hypocenter locations indicate a zone of concentrated seismicity north of the point of highest measured uplift. An inward-dipping elliptical hypocenter pattern suggests a ring fault.}, added-at = {2012-09-01T13:08:21.000+0200}, author = {Aster, R. C. and Meyer, R. P.}, biburl = {https://www.bibsonomy.org/bibtex/2873ec3324a8f126040aa98ad02071588/nilsma}, day = 20, doi = {10.1016/0040-1951(88)90173-4}, interhash = {9aae8db90cdb29055b77f6ba24da0521}, intrahash = {873ec3324a8f126040aa98ad02071588}, issn = {00401951}, journal = {Tectonophysics}, keywords = {geophysics seismology}, month = jun, number = {3-4}, pages = {195--218}, timestamp = {2021-02-09T13:26:58.000+0100}, title = {Three-dimensional velocity structure and hypocenter distribution in the Campi Flegrei caldera, Italy}, url = {http://dx.doi.org/10.1016/0040-1951(88)90173-4}, volume = 149, year = 1988 }