The Upper Crustal P-wave Velocity Structure of Newberry Volcano, Central Oregon
Datum
2011-06
Autor:innen
Zeitschriftentitel
ISSN der Zeitschrift
Bandtitel
Verlag
University of Oregon
Zusammenfassung
The upper-crustal seismic-velocity structure of Newberry volcano, central Oregon, is imaged using P-wave travel time tomography. The inversion combines a densely-spaced seismic line collected in 2008 with two USGS seismic experiments from the 1980s. A high-velocity ring (7 km EW by 5 km NS) beneath the inner caldera faults suggests an intrusive ring complex 200 to 500 m thick. Within this ring shallow low velocities (<2 km depth) are interpreted as caldera fill and a subsided block. High velocities below 2 km depth could be intrusive complexes. There appears to be a low-velocity body at 3-6 km depth beneath the center of the volcano. This region is poorly resolved in the inversion because the ray paths bend around the low-velocity body. The 2008 data also recorded a secondary arrival that may be a delayed P-wave interacting with the low-velocity body.
Beschreibung
xii, 98 p. : ill. (some col.)
Schlagwörter
Geophysics, Arrival, Newberry Volcano (Or.), Secondary, Seismic, Tomography, Volcanoes