The topic for the ESCONI June 2023 General Meeting is "Using geophysics to capture Earth burps and other processes during flow through karst conduits". Our speaker is Andrew Luhmann Assistant Professor of Geology in the Department of Earth and Environmental Science, Wheaton College, in Wheaton, IL.
Karst aquifers are important water resources that are susceptible to contamination from land surface activities. Traditional monitoring strategies rely on spring and well sampling to learn about these flow systems, but we are using geophysics to understand the karst aquifer architecture, including the conduits where much of the flow occurs through these systems as well as the relevant processes that happen within them. During a pilot study in a karst aquifer in Minnesota, we monitored seismic responses during water injection experiments and following a large rainfall event, which caused a discharge increase at Bear Spring and ground motion that originated from multiple source locations. Based on observations and calculations, we suggest that the largest signals resulted from the release of overpressurized air pockets in karst conduits as water levels were rising, where energy was released as the pressurized air encountered pathways to escape from the conduits. Furthermore, we monitored seismic and tilt responses over a three-year period at the Santa Fe River Sink-Rise flow system in Florida, where water flows through conduits 20 m in diameter that are 30 m below the surface. Our modeling efforts have shown that water pressure changes in the conduits cause land surface displacement and tilt, and that this may provide information on conduit location and size. Geophysical tools enable monitoring of fundamental flow processes and dynamics beyond what is possible with traditional monitoring strategies, and our ongoing research is trying to use this information to better characterize the subsurface, identify karst conduits, and monitor for subsurface flow.
Topic: Using geophysics to capture Earth burps and other processes during flow through karst conduits
Time: Jun 9, 2023 08:00 PM Central Time (US and Canada)
Join Zoom Meeting
https://us02web.zoom.us/j/83491743063?pwd=MWZYd2V3YWVuZFJOQlhsZGpEQnRMdz09
Meeting ID: 834 9174 3063
Passcode: 196595
One tap mobile
+19292056099,,83491743063#,,,,*196595# US (New York)
+16469313860,,83491743063#,,,,*196595# US
Dial by your location
+1 929 205 6099 US (New York)
+1 646 931 3860 US
+1 305 224 1968 US
+1 309 205 3325 US
+1 312 626 6799 US (Chicago)
+1 301 715 8592 US (Washington DC)
+1 669 900 6833 US (San Jose)
+1 689 278 1000 US
+1 719 359 4580 US
+1 253 205 0468 US
+1 253 215 8782 US (Tacoma)
+1 346 248 7799 US (Houston)
+1 360 209 5623 US
+1 386 347 5053 US
+1 507 473 4847 US
+1 564 217 2000 US
+1 669 444 9171 US
Meeting ID: 834 9174 3063
Passcode: 196595
Find your local number: https://us02web.zoom.us/u/kb2UQdYO3Y
