Atlanta Geological Society Newsletter ODDS AND ENDS Dear AGS members, February Meeting BOOM! And like that winter is over and I have a yard full of daffodils. Checking today and it was Join us Tuesday, February 27, 2018 at the almost 80˚, 20˚ above average. In today’s news is Fernbank Museum of Natural History, 760 the report that at least 24 cities recorded their Clifton Road NE, Atlanta GA. The hottest February temperature on record on meeting/dinner starts at 6:30 pm and the Wednesday. And I saw that the Artic recently has been some 45˚ above average, above freezing in meeting starts approximately 7 p.m. some places. Given who I work for, I’ll say that it is my personal observation that climate is changing. This month’s presentation is: “Hydrologic I know better than to say that one event makes a Drivers of Harmful Algal Blooms in two trend, but this is starting to add up that only the Piedmont Reservoirs” presented by most skeptical among us can deny something isn’t Ms. Abigail Knapp. Please find more changing the weather. information about Abigail’s bio on Page 2 of the newsletter. Geology moves so slowly but what could these changes mean? Would you get more weathering Please come out, enjoy a bite to eat, the from more times through the freeze/thaw cycle? camaraderie, an interesting presentation and Would the elevated temperature overall increase the perhaps some discussion on the importance overall thermodynamics of soil formation? One of accurate mineral characterization. Also, would assume that permafrost would be affected in coverage but none of us are involved in research in the differences that can exist between that world. It does make me appreciate the work of mineralogical, industrial and regulatory Dr. Kim Cobb at GT who spoke to us in 2016. definitions for minerals. Speaking of speakers, I enjoyed Dr. Tony Martin’s talk last month on trace fossils, specifically trace www.atlantageologicalsociety.org fossils. By definition, Ichnology. Which reminds me of a podcast I found all about ‘Ologies’. The facebook.com/Atlanta-Geological-Society first episode was about a vulcanologist. Give a listen. https://www.alieward.com/ologies/ Hope to see you Tuesday! Ben Bentkowski, President Page 2 AGS February 2018 This Month’s Atlanta Geological Society Speaker Hydrologic Drivers of Harmful Algal Blooms in two Piedmont Reservoirs Ms. Abigail Knapp is a 2nd year graduate student in her last semester at the University of Georgia. She is researching in the Water Resources and Remote Sensing Lab in the Geology Department. After graduation, Abigail will seek work in the limnological and water resources science within a state agency. Other than hydrology, she enjoys ignimbrite petrography and collecting feldspars. Abstract: Reservoirs are central to freshwater resource management in the Southeast, but are often at risk of eutrophication and recurring harmful algal blooms. While the extreme hydrologic events such as flooding and drought are though to control the onset and success of these blooms, the spatiotemporal dynamics are yet to be fully understood. This study looked at the systems of blooms, storms, and drought in Lake Allatoona and Lake Lanier using historical datasets and satellite remote sensing, and modeled the relationships in time and space. Knapp, Abigail S., Milewski, Adam M., and Rotz, Rachel R., 2017. Temporal Relationship between Drought-Precipitation Patterns and the Onset, Duration, and Severity of Freshwater Harmful Algal Blooms in Lake Allatoona, GA. Geological Society of America Southeastern Section, accepted. Saenger, Abigail, 2013. Melt Inclusion Study of the East Fork Rhyolite Member of the Valles Caldera, New Mexico. Center for Undergraduate Research Opportunities Abstracts with Program, p. 92. Saenger, Abigail L., and Swanson, Samuel E., 2012. Mineralogy of Primary Phosphate Minerals in Li Pegmatites of the Kings Mountain District, North Carolina. Geological Society of America Southeastern Section Abstracts with Program v 44. Hogan, Davison L., Tabor, Beth M., Harper, John. R., North, Brandon K., Vanhazebroeck, Ethan, Lawler, Jesse D., Saenger, Abigail L., Taylor, Nicholas J., Fleisher, Christopher J., and Swanson, Samuel E., 2012. Comparison of mineralogy of Li Pegmatites in the Kings Mountain District, North Carolina. Geological Society of America Southeastern Section Abstracts with Program v 44. AGS February 2018 Page 3 Global Patterns of Nitrate Storage in The Unsaturated Zone The unsaturated (vadose) zone between the base of soils and the water table can be an important store of nitrate. Water moves slowly downward through the unsaturated zone and so a large store of nitrate can accumulate if this water contains nitrate derived from surface sources such as fertilizer. Release of this store can affect ground- and surface water quality for decades and it can continue for a long time after changes in farming practice that reduce nitrate leaching. To better understand the extent of the problem, the British Geological Survey has made the first global-scale quantification of nitrate stored in the vadose zone between 1900 and 2000. Increases in nitrate storage in the unsaturated zone though space and time To estimate nitrate stored in the unsaturated zone, we linked mathematical models of nitrate leaching from the base of the soil zone with estimates of groundwater recharge, unsaturated-zone porosity and the depth to groundwater. Conceptual model of nitrate stored in the unsaturated zone. Our modelling showed a substantial continuous increase in nitrate stored in the unsaturated zone over the last century. The peak nitrate storage in 2000 was estimated to be up to 1814 teragrams (Tg) of nitrogen (N). This is equivalent to up to 200 per cent of the inorganic N stored in soils. Spatially, the unsaturated-zone nitrate storage is greatest in North America, China and central and eastern Europe, where the depth to water table is large and there is an extensive history of agricultural fertilizer use. Nitrate storage patterns To better understand trends in nitrate storage, we grouped the nitrate storage responses for river catchments across the globe. The groups show clear differences and trends, with a distinct split between developed (USA, Europe) and developing (Africa, East Asia) countries. In the developed group, current nitrate leaching into the unsaturated zone is decreasing, as a result of improved regulation and farming practice. In contrast, in the developing countries nitrate leaching shows continuous increases associated with rapid, early development and growing intensification of fertilized agriculture. Page 4 AGS February 2018 Global Patterns of Nitrate Storage in The Unsaturated Zone (Continued) Global increase in nitrate stored in the unsaturated zone. Spatial distribution of nitrate in the unsaturated zone. Implications for environmental policy The large store of nitrate in the unsaturated zone means that the use of soil-nitrate leaching estimates alone as an indicator of nitrate pollution is likely to be inappropriate. The distribution of unsaturated-zone nitrate storage can give policy makers and decision makers a first global indication of where this store may be significant and where delays in improvements in groundwater and surface water quality can be expected. This is important for assessing the effectiveness of nitrate management measures and timescales for achieving environmental objectives. The different nitrate storage characteristics observed highlight the need for different management strategies to tackle nitrate pollution across developing and developed countries. However, in both cases, it is essential that catchment retention processes, such as unsaturated-zone storage, are considered. Other temporary stores of nitrate such as storage in soil organic matter and in riparian zones also need to be quantified if fully integrated pollution-management strategies are to be developed. Read more about this article at: http://www.bgs.ac.uk/research/groundwater/quality/nitrate/global‐unsaturated‐zone.html Vast Bioenergy Plantations Could Suck up Carbon and Stave Off Climate Change. They Would Also Radically Reshape the Planet. On a sunny day this past October, three dozen people file into a modest, mint-green classroom at Montana State University (MSU) in Bozeman to glimpse a vision of the future. Some are scientists, but most are people with some connection to the land: extension agents who work with farmers, and environmentalists representing organizations such as The Nature Conservancy. They all know that climate change will reshape the region in the coming decades, but that's not what they've come to discuss. They are here to talk about the equally profound impacts of trying to stop it. Paul Stoy, an ecologist at MSU, paces in front of whiteboards in a powder blue shirt and jeans as he describes how a landscape already dominated by agriculture could be transformed yet again by a different green revolution: vast plantations of crops, sown to sop up carbon dioxide (CO2) from the sky. “We have this new energy economy that's necessary to avoid dangerous climate change, but how is that going to look on the AGS February 2018 Page 5 Vast Bioenergy Plantations Could Suck up Carbon and Stave Off Climate Change. They Would Also Radically Reshape the Planet. (Continued) ground?” he asks. In 2015, the Paris climate agreement established a goal of limiting global warming to “well below” 2°C. In the most recent report of the Intergovernmental Panel on Climate Change, researchers surveyed possible road maps for reaching that goal and found something unsettling. In most model scenarios, simply cutting emissions isn't enough. To limit warming, humanity also needs negative emissions technologies (NETs) that, by the end of the century, would remove more CO2 from the atmosphere than humans emit. The technologies would buy time for society to rein in carbon emissions, says Naomi Vaughan, a climate change scientist at the University of East Anglia in Norwich, U.K. “They allow you to emit more CO2 and take it back at a later date.” Whether that's doable is another question.