GSW0092 Effects of texture and point defect on ultrasonic wave velocities and examination of orientation effects on point defect growth estimated by cross slip simulations

2003 ◽  
Vol 2003.2 (0) ◽  
pp. _GSW0092-1-_GSW0092-6
Author(s):  
Shihua Tang ◽  
Michiaki Kobayashi ◽  
Setsuo Miura ◽  
Hiroyuki Fujiki
Keyword(s):  
Point Defect ◽  
Ultrasonic Wave ◽  
Cross Slip ◽  
Wave Velocities ◽  
Orientation Effects ◽  
Defect Growth

scholarly journals The permeability and elastic moduli of tuff from Campi Flegrei, Italy: implications for ground deformation modelling

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 25-44 ◽  
Author(s):  
M. J. Heap ◽  
P. Baud ◽  
P. G. Meredith ◽  
S. Vinciguerra ◽  
T. Reuschlé
Keyword(s):  
Ultrasonic Wave ◽  
Elastic Moduli ◽  
Ground Deformation ◽  
Laboratory Data ◽  
Campi Flegrei ◽  
Pore Collapse ◽  
Campanian Ignimbrite ◽  
Wave Velocities ◽  
Neapolitan Yellow Tuff ◽  
Dynamic Elastic Moduli

Abstract. The accuracy of ground deformation modelling at active volcanoes is a principal requirement in volcanic hazard mitigation. However, the reliability of such models relies on the accuracy of the rock physical property (permeability and elastic moduli) input parameters. Unfortunately, laboratory-derived values on representative rocks are usually rare. To this end we have performed a systematic laboratory study on the influence of pressure and temperature on the permeability and elastic moduli of samples from the two most widespread lithified pyroclastic deposits at the Campi Flegrei volcanic district, Italy. Our data show that the water permeability of Neapolitan Yellow Tuff and a tuff from the Campanian Ignimbrite differ by about 1.5 orders of magnitude. As pressure (depth) increases beyond the critical point for inelastic pore collapse (at an effective pressure of 10–15 MPa, or a depth of about 750 m), permeability and porosity decrease significantly, and ultrasonic wave velocities and dynamic elastic moduli increase significantly. Increasing the thermal stressing temperature increases the permeability and decreases the ultrasonic wave velocities and dynamic elastic moduli of the Neapolitan Yellow Tuff; whereas the tuff from the Campanian Ignimbrite remains unaffected. This difference is due to the presence of thermally unstable zeolites within the Neapolitan Yellow Tuff. For both rocks we also find, under the same pressure conditions, that the dynamic (calculated from ultrasonic wave velocities) and static (calculated from triaxial stress-strain data) elastic moduli differ significantly. The choice of elastic moduli in ground deformation modelling is therefore an important consideration. While we urge that these new laboratory data should be considered in routine ground deformation modelling, we highlight the challenges for ground deformation modelling based on the heterogeneous nature (vertically and laterally) of the rocks that comprise the caldera at Campi Flegrei.

scholarly journals Texture and Cross Slip Effects on Ultrasonic Wave Velocity Changes Under Simple and Pure Shear States.

2001 ◽  
Vol 67 (660) ◽  
pp. 1402-1408 ◽  
Author(s):  
Shihua TANG ◽  
Michiaki KOBAYASHI ◽  
Setsuo MIURA ◽  
Hiroryuki FUJIKI ◽  
Kazuya IWABUCHI ◽  
...  
Keyword(s):  
Ultrasonic Wave ◽  
Wave Velocity ◽  
Pure Shear ◽  
Cross Slip ◽  
Ultrasonic Wave Velocity ◽  
Slip Effects ◽  
Velocity Changes

Ultrasonic wave velocities in the structure II clathrate hydrate THF�17H2O

1984 ◽  
Vol 3 (10) ◽  
pp. 904-906 ◽  
Author(s):  
M. Bathe ◽  
S. Vagle ◽  
G. A. Saunders ◽  
E. F. Lambson
Keyword(s):  
Ultrasonic Wave ◽  
Clathrate Hydrate ◽  
Wave Velocities ◽  
Structure Ii Clathrate Hydrate
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