An effective-medium model for P-wave velocities of saturated, unconsolidated saline permafrost
To better understand the relationship between P-wave velocities and ice content in saturated, unconsolidated saline permafrost, we constructed an effective-medium model based upon ultrasonic P-wave data that were obtained from earlier laboratory studies. The model uses a two-end-member mixing approa...
| Published in: | GEOPHYSICS |
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| Main Authors: | , , , |
| Language: | unknown |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://www.osti.gov/servlets/purl/1476488 https://www.osti.gov/biblio/1476488 https://doi.org/10.1190/GEO2016-0474.1 |
| Summary: | To better understand the relationship between P-wave velocities and ice content in saturated, unconsolidated saline permafrost, we constructed an effective-medium model based upon ultrasonic P-wave data that were obtained from earlier laboratory studies. The model uses a two-end-member mixing approach in which an ice-filled, fully frozen end member and a water-filled, fully unfrozen end member are mixed together to form the effective medium of partially frozen sediments. This mixing approach has two key advantages: (1) It does not require parameter tuning of the mixing ratios, and (2) it inherently assumes mixed pore-scale distributions of ice that consist of frame-strengthening (i.e., cementing and/or loadbearing) ice and pore-filling ice. The model-predicted P-wave velocities agree well with our laboratory data, demonstrating the effectiveness of the model for quantitatively inferring ice content from P-wave velocities. The modeling workflow is simple and is largely free of calibration parameters -attributes that ease its application in interpreting field data sets. |
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