Abstract
The dissipation factor (Q-1) for torsional vibration has been measured for several low-porosity crystalline rocks up to 0.5GPa confining pressure. Q was measured at frequencies of approx 10kHz by a resonant bar technique in which cylindrical samples are enclosed in a thin-walled copper sheath welded to copper end plugs, with piezoelectric transducers bonded to the ends. Some of the samples were encapsulated under laboratory conditions (30-40% humidity) whereas others were encapsulated in vacuum (approx 10-5torr). Q was found to increase by 103 or more between 0 and 0.5GPa for most of the samples. In some cases, values well over 2000 were found at 0.5GPa. For some of the rocks, including vacuum-dry as well as air-dry samples, Q was found to continue increasing pressure even after most of the cracks were closed. A significant time dependence was also observed. After any increase or decrease in confining pressure, Q was observed to increase slowly for several days at least. Possible attenuation mechanisms and implications for the earth's interior are discussed.-Authors
| Original language | English (US) |
|---|---|
| Pages (from-to) | 147-158 |
| Number of pages | 12 |
| Journal | Unknown Journal |
| State | Published - Jan 1 1982 |
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All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Earth and Planetary Sciences(all)
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Pressure dependence of Q in selected rocks. / Katahara, K. W.; Manghnani, M. H.; Devnani, N.; Tittmann, Bernhard R.
In: Unknown Journal, 01.01.1982, p. 147-158.Research output: Contribution to journal › Article
TY - JOUR
T1 - Pressure dependence of Q in selected rocks.
AU - Katahara, K. W.
AU - Manghnani, M. H.
AU - Devnani, N.
AU - Tittmann, Bernhard R.
PY - 1982/1/1
Y1 - 1982/1/1
N2 - The dissipation factor (Q-1) for torsional vibration has been measured for several low-porosity crystalline rocks up to 0.5GPa confining pressure. Q was measured at frequencies of approx 10kHz by a resonant bar technique in which cylindrical samples are enclosed in a thin-walled copper sheath welded to copper end plugs, with piezoelectric transducers bonded to the ends. Some of the samples were encapsulated under laboratory conditions (30-40% humidity) whereas others were encapsulated in vacuum (approx 10-5torr). Q was found to increase by 103 or more between 0 and 0.5GPa for most of the samples. In some cases, values well over 2000 were found at 0.5GPa. For some of the rocks, including vacuum-dry as well as air-dry samples, Q was found to continue increasing pressure even after most of the cracks were closed. A significant time dependence was also observed. After any increase or decrease in confining pressure, Q was observed to increase slowly for several days at least. Possible attenuation mechanisms and implications for the earth's interior are discussed.-Authors
AB - The dissipation factor (Q-1) for torsional vibration has been measured for several low-porosity crystalline rocks up to 0.5GPa confining pressure. Q was measured at frequencies of approx 10kHz by a resonant bar technique in which cylindrical samples are enclosed in a thin-walled copper sheath welded to copper end plugs, with piezoelectric transducers bonded to the ends. Some of the samples were encapsulated under laboratory conditions (30-40% humidity) whereas others were encapsulated in vacuum (approx 10-5torr). Q was found to increase by 103 or more between 0 and 0.5GPa for most of the samples. In some cases, values well over 2000 were found at 0.5GPa. For some of the rocks, including vacuum-dry as well as air-dry samples, Q was found to continue increasing pressure even after most of the cracks were closed. A significant time dependence was also observed. After any increase or decrease in confining pressure, Q was observed to increase slowly for several days at least. Possible attenuation mechanisms and implications for the earth's interior are discussed.-Authors
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M3 - Article
AN - SCOPUS:0020444744
SP - 147
EP - 158
JO - [No source information available]
JF - [No source information available]
SN - 0042-1215
ER -