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oai:keep.lib.asu.edu:node-1953262024-12-23T18:01:48Zoai_pmh:alloai_pmh:repo_items

195326 https://hdl.handle.net/2286/R.2.N.195326 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2024 133 pages Masters Thesis Academic theses Text eng Pond, Kristin Lyne Reano, Darryl Whipple, Kelin Arrowsmith, Ramon Arizona State University Partial requirement for: M.S., Arizona State University, 2024 Field of study: Geological Sciences Quantifying rock mass strength (RMS) in geomorphologically relevant scale has been difficult due to rock property heterogeneities, including especially fracture density which strongly influences RMS. To investigate the relationship between field-scale and lab-based intact rock strength, tensile strength (σt) and core- and field-based seismic p-wave velocities (Vpc, Vpf) were collected from Colorado Plateau crystalline silicate, siliciclastic, and carbonate rock formations. These data show that σt correlates with the square of Vpc, suggesting the potential of seismic refraction for quantifying RMS. I measure effective RMS using a proxy, the product of intact core tensile strength (σt) and the squared ratio of Vpf to Vpc, and show how the reduction of p-wave velocities in the field relative to intact cores can serve as a metric of strength reduction from fracturing in bedrock. Furthermore, the carbonates demonstrated relatively low σt values compared to the silicate samples for the same p-wave velocity. The lower strength differentiation of the carbonates likely results from differences in geomechanical failure behavior between more brittle (carbonate) and more ductile (silicate) rocks, consistent with previous lab-based studies on the brittle-ductile differences in rock strength and properties. Application of this ensemble RMS quantification will enable better constraints on bedrock strength parameters in modeling fluvial incision into bedrock, expected to increase understanding of the relationship between rock properties and channel gradient. With the ultimate intent of contributing to applied geoscience workforce needs and increasing diversity in geoscience, a field-based applied geomorphology education module was developed to teach the concept of quantifying field-scale rock strength using seismic velocity as proxy for rock mass strength. SocioTransformative constructivism (sTc) has identified increasing self-efficacy as effective for increasing perseverance and diversity in geoscience, and student assessment responses add to this further. With the inclusion of field-based authentic activity and dialogic components, students overall showed promising increases in field experience perception, self-efficacy, and intent to pursue a career in geoscience. Development of student self-efficacy in this field-based applied arena can be utilized in department initiatives for enacting inclusion in geoscience, and contributing to applied geoscience workforce needs for addressing the societal challenges of a changing global climate. geomorphology Geophysics science education For the Quantification of Rock Mass Strength, and Development of Geoscience