24th Annual GSRS Welcome to the 2019 Geosciences Student Research Symposium! GSRS, now in its 24th year is organized entirely by the graduate students in the Geosciences Department. The purpose of GSRS is to give students an opportunity to present their research to their peers and professors in the department. During GSRS students and faculty learn about the diversity of geoscience research that occurs in the department. Students gain practice communicating their research to a broad audience. GSRS offers a unique opportunity for students to give a professional talk in preparation for future talks at national conferences. GSRS brings the department together through scientific talks, poster sessions, and community lunches and dinners! GSRS would not be possible without the help of many people. First, thank you very much to everyone that donated to GSRS through our Virginia Tech Crowdfunding Campaign last fall. This symposium would not be possible without your generosity. Thank you to Carol Lee Donuts, Panera Bread, The Beast of Blacksburg, Due South, and Professional Touch Catering for providing food and drinks throughout the symposium. Thank you very much to everyone in the Department of Geosciences: students, faculty, and staff for helping make GSRS possible. A special thank you goes out to members of Sigma Gamma Epsilon for helping set up for GSRS. Additionally, thank you to ICTAS at Virginia Tech for allowing us to use Kelly Hall for our symposium. We would also like to thank Dean Karen DePauw and Dean Sally Morton for attending this event. Without all this support, GSRS would not be possible! 2019 GSRS Committee Chair: Allie Nagurney Abstract Book/Scheduling: Lisa Whalen Communications: Aly Hoeher, Jess DePaolis, Yezi Yang Faculty Advisor: Jim Spotila Food: Katie Kreuger, Morrison Nolan, Natalia Varela, Priyanka Bose Fundraising: Amin Abbasi, Drew Parent, Stacey Law, Grady Konzen, Laura Szczyrba Judiciary: Eszter Sendula, Max Schwid Moderators: Ben Kligman Senior Advisors: Kannihka Kolandaivelu, Lowell Moore Undergraduate Poster Session: Khanh To Website: Sarah Ulrich, Nathan Roethlisberger Workshop Series: Devin Hoffman 2019 GSRS Donors Amin Abbasi Baghbadorani Christina Blue Blaine Bolduc Myron Broadwell Priyanka Bose Kristie Caddick Sharon Collins Richard DePaolis Ben Gill Susan Gill Aly Hoeher Devin Hoffman Steve Holbrook Diane Janson Sofia Kaczor Jay and Paula Law Stacey Law Changyeol Lee Robert Lowell Rui Maia Marc Michel Ladimer and Anna Nagurney David Nelms Sterling Nesbitt Laura Neser Brian Romans Madeline Schreiber Eszter Sendula James Spotila Michelle Stocker Laura Szczyrba Robert Tracy Emma Tulsky Rhonda Welch Mary Hawkins Wicks Nicholas Wigginton Shuhai Xiao Ying Zhou GSRS Schedule Thursday, Friday, Presenter Presenter February 21 February 22 8:00-9:00 Breakfast 8:30-9:00 Breakfast 8:50 Opening Remarks 8:55 Opening Remarks Session 1 Session 5 8:55-9:10 Kristin Chilton 9:00-9:15 Brenen Wynd 9:10-9:25 Kathryn Krueger 9:15-9:30 Zhen Guo 9:25-9:40 Lisa Whalen 9:30-9:45 Richard Jayne 9:40-9:55 Hao Wu 9:45-10:00 Andrew Parent 9:55-10:10 Aly Hoeher 10:00-10:15 Emmanuel Njinju 10:10-10:25 Laura Szczyrba 10:15-10:35 Coffee Break 10:30-12:30 Poster Session & Lunch Session 6 12:45-12:50 Annoucements 10:35-10:50 Khanh To Session 2 10:50-11:05 Shangxin Liu 12:50-1:05 Jessica DePaolis 11:05-11:20 Natalia Varela 1:05-1:20 Nathan Roethlisberger 11:20-11:35 Devin Hoffman 1:20-1:35 Tahiry Rajaonarison 11:35-12:05 Up Goer 5 1:35-1:50 McNeill Bauer 12:05-1:55 Poster Session & Lunch 1:50-2:05 Lowell Moore 1:55-2:00 Announcements 2:05-2:20 Coffee Break Session 7 Session 3 2:00-2:15 Calvin Mako 2:20-2:35 Selva Marroquín 2:15-2:30 Graydon Konzen 2:35-2:50 Shuyang Sun 2:30-2:45 Dana Korneisel 2:50-3:05 Morrison Nolan 2:45-3:00 Ben Kligman 3:05-3:20 Stacey Law 3:00-3:15 Max Schwid 3:20-3:35 Chris Griffin 3:15-3:30 Coffee Break 3:35-3:50 Coffee Break Session 8 Session 4 3:30-3:45 Tyler Rothschild 3:50-4:05 Matt LeRoy 3:45-4:00 Michael Vadman 4:05-4:20 Grant Euen 4:00-4:15 Amin Abbasi Baghbadorani 4:20-4:35 Joshua Jones 4:15-4:30 Yezi Yang 4:35-4:50 Priyanka Bose 4:30-4:45 Alireza Namayandeh 4:50 Closing Announcements 4:45-5:00 Josh Benton 5:00 Closing Remarks Reception, Museum of 17:30 Onwards Geosciences Undergraduate Posters Undergraduate Posters 1 David Belisle 7 Camille Do 2 Siqi Che 8 Laura Garcia Ramos 3 Roberto Gorjon-Andujar 9 Ronald Navarro 4 Joshua Kling 10 ThaoVy Nguyen 5 Sarah Morgan 11 Jordan Pritchard 6 Devin Seran 12 Michael Zigah Graduate Abstracts IMAGING VOIDS AND FRACTURES WITHIN AN UNDERGROUND MINE USING GROUND PENETRATING RADAR ABBASI BAGHBADORANI, Amin, Dept. of Geosciences, Virginia Tech, Blacksburg, VA 24061 Two of the most dangerous events in underground mining are encountering unexpected water influx and structural instability due to excavation into undetected voids and fractures underground. The most common detection method before excavation is probe drilling, either from the mine or from the surface. Mine engineers decide on the spacing and the depth of probe drilling based on the planned excavation depth and the nature of previous voids encountered. However, drilling often misses or underestimates the size of fractures and voids between drill holes or beyond the depth of the holes. This project is working in collaboration with an underground limestone mine in the eastern United States. Excavation has unexpectedly encountered fractures and karst voids which have led to significant loss of time and resources as well as posed safety hazards. Ground or rock penetrating radar (GPR) can detect fractures and voids within rock. GPR equipment was modified to acquire 2D and 3D data on the walls of the mine. Initial data were acquired within a 10x25x25-m triangular pillar to allow calibration of radar images to pillar walls. The data detected and imaged a karst cavern known to be >20-m3 and two smaller voids. The rough geometry of the pillar wall and the complex geometry of the voids required careful consideration of 3D geometry during data processing. Subsequently, 2D and 3D migration imaged the voids at their proper 3D locations within the pillar. Ongoing work involves synthetic radargram modeling to predict fracture aperture and infill. This research will guide future practical radar applications to detect fractures and voids prior to excavation allowing hazard mitigation. Advisor: Dr. J. A. Hole FACTORS REGULATING THE FORMATION OF ALLOPHANE AND IMOGOLITE NANOPARTICLES BAUER, McNeill, Dept. of Geosciences, Virginia Tech, Blacksburg, VA 24061 Nanosized aluminosilicate minerals allophane and imogolite strongly control the physical and chemical behavior of soil and hold promise for technological applications. In nature, allophane and imogolite are often observed together in varying proportions. Similarly, laboratory synthesis by various methods usually does not result in pure phases. These observations suggest they form contemporaneously at a wide range of solution chemical conditions. It remains unclear what factors determine how and when these phases form in solution, which limits our understanding of their occurrence in nature and the laboratory. The objective of this study is to understand and explain what solution chemical and physical conditions control the formation of synthetic imogolite and allophane. We have developed synthesis procedures for allophane and imogolite that mix tetraethyl orthosilicate (TEOS) into a solution of aluminum chloride hexahydrate. Idealized Al:Si ratios are set between 2 and 0.5, with initial aluminum concentrations [Al]=0.005M to 0.2M. The solution is then hydrolyzed by the controlled addition of 0.1 M NaOH to total metal:OH ratios of 1/2 to 3. The solution is stirred for 1 h at 400 rpm and heated for 7 d at 95 °C. Dialyzed products were characterized ex situ using powder x-ray diffraction (pXRD) and small-angle x-ray scattering (SAXS). Phase abundances were estimated from pXRD by linear combination fitting (LCF). Multivariate regression was used to simultaneously test for the influence of the variables including pH, concentration, NaOH addition rate, and elemental ratios. Given the final synthesis product is some combination of allophane, imogolite, and amorphous silica (amSi), multivariate regression can quantify the effect that each synthesis variable has on the abundances of each of these phases. Increasing starting reagent concentration by 0.1M tended to increase the allophane proportion while decreasing the imogolite and amSi proportion at rates of +0.26 dM-1, -0.22 dM-1, and - 0.05 dM-1 respectively. Raising the initial pH to 10, from 3, which is the system without adjustment, tended to greatly increase the imogolite abundance, while decreasing the allophane and amSi abundance, by +0.5, -0.2, and -0.3, respectively. Increasing the initial Al:Si ratio from 1:1 to 2:1 decreased amSi proportion by -0.23, it also increased allophane proportion per 1 increase in ratio by +0.24, while having no impact on the proportion of imogolite. These results allow for the production of a model that can be used to optimize the synthesis of allophane and imogolite. The same approach can be applied to other types of nanoparticles. Advisor: Dr. F.M.Michel CHARACTERIZING SUBSURFACE HYDROLOGIC FLUXES WITHIN A GLACIATED WATERSHED BENTON, Joshua, Dept. of Geosciences, Virginia Tech, Blacksburg, VA 24061 Chemical weathering within the critical zone is an important source of solutes as elements are released from bedrock and regolith into solution. This study investigates how the spatial architecture of the critical zone influences hydrologic and solute fluxes throughout multiple sub- catchments in a glaciated, upland watershed at the Hubbard Brook Experimental Forest in New Hampshire.