GSA Today最新文献

{"title":"The Need for a Paradigm Shift in Science Advocacy","authors":"G. Davidson, C. Hill, K. Wolgemuth","doi":"10.1130/GSATG280GW.1","DOIUrl":"https://doi.org/10.1130/GSATG280GW.1","url":null,"abstract":"Sixteen years into the twenty-first century, many are dismayed at the resiliency of skepticism about science in the United States. On wide-ranging subjects, such as vaccinations, genetically modified foods, climate change, evolution, and the age and origin of the Earth and universe, a sizable percentage of the population continues to hold and promote views that run counter to common scientific understanding. An oft-cited Gallup poll (2015) illustrates the lack of progress. In 1982, a question was posed regarding beliefs about human evolution. At the time, 44% believed God made humans in their present form. After a quarter century of improved educational materials, upgraded K–12 science standards, and several successful court battles to curb anti-science influences, that number has remained essentially unchanged. The last poll in 2014 pegged the number at 42% (Gallup, 2015). Other polls tell a similar story. A 2014 poll by the Associated Press found that 4 out of 10 people in the United States have doubts about the validity of a 4.5-billionyear history for the Earth and about the evolution of life forms through a process of natural selection. A 51% majority is skeptical about the “Big Bang” (Borenstein and Agiesta, 2014). The Pew Foundation took a different approach, asking people whether they thought scientists were in agreement on these topics. More than half the people surveyed believe scientists are currently divided on the origin of the universe, and more than a third believe scientists still lack internal consensus on evolution (Funk and Rainie, 2015). The outlook for the near future is not encouraging. Berkman and Plutzer (2011) The Need for a Paradigm Shift in Science Advocacy","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"58-59"},"PeriodicalIF":0.0,"publicationDate":"2017-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45758540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extracting Bulk Rock Properties from Microscale Measurements: Subsampling and Analytical Guidelines","authors":"M. McCanta, M. Dyar, P. Dobosh","doi":"10.1130/GSATG290A.1","DOIUrl":"https://doi.org/10.1130/GSATG290A.1","url":null,"abstract":"Geologists are commonly faced with questions relating to representative sampling at all scales: outcrop to formation, hand sample to bulk rock, microanalysis to overall chemistry. A new computer model allows quantitative answers to the question of how many different microanalysis spots are needed to determine different bulk properties of a rock for any type and scale of measurement, including whole rock composition and oxidation state. The relationships among grain size, glass ordering, and microbeam size, the composition and heterogeneity of the rocks studied, and the location of the analyses relative to textural features are all important. These variables can be grouped into those that affect the heterogeneity (H) of the material versus the scale of measurements (M) being used. For rocks where H (grain size, glass longor short-range ordering, or composition) <<M (beam size), an average of fewer than ten analyses will yield a representative bulk rock composition no matter how heterogeneous the phase assemblage. For rocks where H  M, hundreds of analyses may be needed to result in acceptable analytical precision. Guidelines for how many samples/analyses are needed to represent geologic materials at any scale are presented.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"4-9"},"PeriodicalIF":0.0,"publicationDate":"2017-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41487821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing Undergraduate Interest to Learn Geoscience with GPS-based Augmented Reality Field Trips on Student's Own Smartphones","authors":"Natalie Bursztyn, Brett E. Shelton, A. Walker, J. Pederson","doi":"10.1130/GSATG304A.1","DOIUrl":"https://doi.org/10.1130/GSATG304A.1","url":null,"abstract":"Field trips are a reliable method for attracting students into geoscience, yet for many high-enrollment college introductory courses, field trips are often impractical. Furthermore, introductory courses are often taught with a traditional lecture style that is poor at engaging students. This study examines the impact of augmented reality (AR) field trip exercises on the interest levels of students using readily accessible mobile devices (smartphones and tablets) as a means to provide simulated field trip experiences to a larger number of learners. The results of this study, involving 874 students from five different institutions, show that students who completed three geospatially oriented Grand Canyon field trip game modules were significantly more interested in learning the geosciences than control students and participants who completed only one module. More comprehensively, results from hierarchical linear modeling indicate three strong predictors of student interest in learning the geosciences: (1) the student’s initial interest, (2) being a STEM major, and (3) the number of AR field trip modules students complete. Notably, the race and gender of participants are not factors. Augmented reality field trips for mobile devices have potential to be an accessible and financially viable means to bring field trips to a diversity of students who would otherwise experience none. Results indicate these AR field trips increase student motivation to pursue geoscience learning.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":" ","pages":"4-10"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49063782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The High Plains Aquifer: Can We Make It Last?","authors":"Susan G. Stover, R. Buchanan","doi":"10.1130/GSATG318GW.1","DOIUrl":"https://doi.org/10.1130/GSATG318GW.1","url":null,"abstract":"gated crops depend on one massive but dwindling water source: the High Plains aquifer. Declining water levels in the High Plains aquifer and responses to those declines are resource challenges that necessitate input from geoscientists. The High Plains aquifer, which underlies parts of eight states from South Dakota to Texas, consists of several interconnected aquifers, including the Ogallala aquifer. Unequally distributed, most of the southern two-thirds is in serious decline; water levels have dropped >150 ft since pre-development in areas of Texas and Kansas (Fig. 1; McGuire, 2014). Roughly 19.6 million acre-feet were pumped in 2005, primarily for irrigation (McGuire, 2009), a quantity that exceeds the basin-wide average annual inflow of the Colorado River (Bureau of Reclamation, 2011). In 2013, three times more water was pumped from the aquifer in Kansas than the estimated natural recharge rate (Buchanan et al., 2015). Kansas warns that without changes, “70% of the aquifer [in Kansas] will be depleted within 50 years” (Kansas Water Office and Kansas Department of Agriculture, 2015). Water quality also impairs the aquifer in some regions (Whittemore, 2012). The High Plains aquifer is the source for a highly productive region of corn, alfalfa, soybeans, wheat, sorghum, and cotton (Cruse et al., 2016). Crops support the numerous cattle feedlots and large dairies that overlie the High Plains aquifer. Meatpacking, milk processing, ethanol plants, and domestic users also rely on the aquifer. It supports the region’s economy and the U.S. food supply. Can the aquifer’s use be slowed and its life extended? The aquifer’s availability to future generations depends on decisions by policy makers, water managers, and especially irrigators. The geoscience community is continually The High Plains Aquifer: Can We Make It Last?","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"44-45"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48272897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diverse Students Can be Attracted to Geoscience","authors":"S. O'Connell, M. Gilmore, Renee Johnson-Thornton, T. Ku, Pete Patton, P. Resor, D. Royer","doi":"10.1130/GSATG288GW.1","DOIUrl":"https://doi.org/10.1130/GSATG288GW.1","url":null,"abstract":"","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"76-77"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48578402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased Land Subsidence and Sea-Level Rise Are Submerging Egypt’s Nile Delta Coastal Margin","authors":"J. Stanley, P. Clemente","doi":"10.1130/GSATG312A.1","DOIUrl":"https://doi.org/10.1130/GSATG312A.1","url":null,"abstract":"Egypt’s Nile delta, only ~1 m above mean sea level at the Mediterranean coast, is subject to uneven rates of submergence. This is a response to several factors leading to increasing land lowering (subsidence) of the northern delta and adjacent seafloor, plus an accelerating rise in eustatic (world) sea level in the Mediterranean. An average eustatic sealevel rise of ~3 mm/yr represents only ~26% to 45% of total relative sea-level rise measured along this margin. Three factors leading to subsidence are neotectonic lowering, compaction of Holocene sequences, and diminished sediment replenishment by much reduced Nile flow to Egypt’s coast. Subsidence accounts for variable average land lowering of ~3.7 mm/yr of section in the NW delta, ~7.7 mm/yr in the N delta, and ~8.4 mm/yr in the NE delta, based on compaction rates of strata thicknesses that decrease down-core between top and base of Holocene sections in 85 drill cores distributed along the delta margin. Among present critical challenges are marked reduction of Nile water and sediment below the High Aswan Dam that can now reach the delta coast. It is expected that problems of fresh water and energy poverty in the lower Nile Basin are likely to be seriously exacerbated in years ahead by construction of Ethiopia’s Grand Renaissance Dam (GERD). Completion of this, the biggest hydroelectric structure in Africa, is this year. Egypt, the Sudan, and Ethiopia must resolve the looming crisis of diminished Blue Nile water and sediment distribution to the lower Nile Basin and Egypt’s delta margin.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"4-11"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44928398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Savor the Cryosphere","authors":"Patrick A. Burkhart, R. Alley, L. Thompson, J. Balog, P. Baldauf, G. Baker","doi":"10.1130/GSATG293A.1","DOIUrl":"https://doi.org/10.1130/GSATG293A.1","url":null,"abstract":"This article provides concise documentation of the ongoing retreat of glaciers, along with the implications that the ice loss presents, as well as suggestions for geoscience educators to better convey this story to both students and citizens. We present the retreat of glaciers—the loss of ice—as emblematic of the recent, rapid contraction of the cryosphere. Satellites are useful for assessing the loss of ice across regions with the passage of time. Ground-based glaciology, particularly through the study of ice cores, can record the history of environmental conditions present during the existence of a glacier. Repeat photography vividly displays the rapid retreat of glaciers that is characteristic across the planet. This loss of ice has implications to rising sea level, greater susceptibility to dryness in places where people rely upon rivers delivering melt water resources, and to the destruction of natural environmental archives that were held within the ice. Warming of the atmosphere due to rising concentrations of greenhouse gases released by the combustion of fossil fuels is causing this retreat. We highlight multimedia productions that are useful for teaching this story effectively. As geoscience educators, we attempt to present the best scholarship as accurately and eloquently as we can, to address the core challenge of conveying the magnitude of anthropogenic impacts, while also encouraging optimistic determination on the part of students, coupled to an increasingly informed citizenry. We assert that understanding human perturbation of nature, then choosing to engage in thoughtful science-based decision-making, is a wise choice. This topic comprised “Savor the Patrick A. Burkhart, Dept. of Geography, Geology, and the Environment, Slippery Rock University, Slippery Rock, Pennsylvania 16057, USA; Richard B. Alley, Dept. of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Lonnie G. Thompson, School of Earth Sciences, Byrd Polar and Climate Research Center, Ohio State University, Columbus, Ohio 43210, USA; James D. Balog, Earth Vision Institute/Extreme Ice Survey, 2334 Broadway Street, Suite D, Boulder, Colorado 80304, USA; Paul E. Baldauf, Dept. of Marine and Environmental Sciences, Nova Southeastern University, 3301 College Ave., Fort Lauderdale, Florida 33314, USA; and Gregory S. Baker, Dept. of Geology, University of Kansas, 1475 Jayhawk Blvd., Lawrence, Kansas 66045, USA Cryosphere,” a Pardee Keynote Symposium at the 2015 Annual Meeting in Baltimore, Maryland, USA, for which the GSA recorded supporting interviews and a webinar.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":"4-10"},"PeriodicalIF":0.0,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44876911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Miocene uplift of the Tian Shan and Altai and reorganization of Central Asia climate","authors":"H. Mix","doi":"10.1130/GSATG305A.1","DOIUrl":"https://doi.org/10.1130/GSATG305A.1","url":null,"abstract":"The timing of high surface topography and the corresponding climatic impacts of the many high ranges north of the Tibetan Plateau, such as the Altai and Tian Shan, remain poorly constrained. Most Neogene reconstructions of Central Asia climate come from interior China, where the influences of Altai and Tian Shan uplift are difficult to deconvolve from effects due to Tibetan Plateau uplift and changes in global climate. We present a new pedogenic carbonate oxygen and carbon isotope record from terrestrial Neogene sediments of the Zaysan Basin in eastern Kazakhstan, which lies upwind of the Altai and Tian Shan, in contrast to the numerous paleoclimate records from interior China. The δ18O values of pedogenic carbonate exhibit a robust 4‰ decrease in the late Neogene—a trend that sharply contrasts with nearly all downwind records of δ18O from Central Asia. We attribute this decrease to the establishment of the modern seasonal precipitation regime whereby Kazakhstan receives the majority of its moisture in the spring and fall, which lowers the δ18O of pedogenic carbonates. The dominance of spring and fall precipitation in Kazakhstan results from the interaction of the mid-latitude jet with the high topography of the Altai and Tian Shan during its movement northward in spring and southward in fall. The late Miocene interaction of the jet with these actively uplifting northern Central Asia ranges reorganized Central Asia climate, establishing starkly different seasonal precipitation regimes, further drying interior Jeremy K. Caves*, Earth System Science, Stanford University, Stanford, California 94305, USA; Bolat U. Bayshashov, Institute of Zoology, Academy of Sciences, Almaty 050060, Kazakhstan; Aizhan Zhamangara, L.N. Gumilyov Eurasian National University, Astana 01000, Kazakhstan; Andrea J. Ritch, Daniel E. Ibarra, Earth System Science, Stanford University, Stanford, California 94305, USA; Derek J. Sjostrom, Geology Program, Rocky Mountain College, Billings, Montana 59102, USA; Hari T. Mix, Environmental Studies and Sciences, Santa Clara University, Santa Clara, California 95053, USA; Matthew J. Winnick, Geological Sciences, Stanford University, Stanford, California 94305, USA; and C. Page Chamberlain, Earth System Science, Stanford University, Stanford, California 94305, USA China, and increasing the incidence of the lee cyclones that deposit dust on the Loess Plateau. We conclude that paleoclimatic changes in Central Asia in the Neogene are more tightly controlled by the interaction of the mid-latitude westerlies with the bounding ranges of northern Central Asia than by changes in the height or extent of the Tibetan Plateau.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47540923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of seismic image quality on fault interpretation uncertainty","authors":"J. Alcalde, C. Bond, G. Johnson, J. F. Ellis, R. Butler","doi":"10.1130/GSATG282A.1","DOIUrl":"https://doi.org/10.1130/GSATG282A.1","url":null,"abstract":"Uncertainty in the geological interpretation of a seismic image is affected by image quality. Using quantitative image analysis techniques, we have mapped differences in image contrast and reflection continuity for two different representations of the same grayscale seismic image, one in two-way-time (TWT) and one in depth. The contrast and reflection continuity of the depth image is lower than that of the TWT image. We compare the results of 196 interpretations of a single fault with the quality of the seismic image. Low contrast and continuity areas correspond to a greater range of interpreted fault geometries, resulting in a broader spread of fault interpretations in the depth image. Subtle differences in interpreted fault geometries introduce changes in fault characteristics (e.g., throw, heave) that are critical for understanding crustal and lithospheric processes. Seismic image quality impacts interpretation certainty, as evidenced by the increased range in fault interpretations. Quantitative assessments of image quality could inform: (1) whether model-based interpretation (e.g., fault geometry prediction at depth) is more robust than a subjective interpretation; and (2) uncertainty assessments of fault interpretations used to predict tectonic processes such as crustal extension.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":" ","pages":"4-10"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49569994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is the Anthropocene an issue of stratigraphy or pop culture","authors":"W. Autin, J. Holbrook","doi":"10.1130/G153GW.1","DOIUrl":"https://doi.org/10.1130/G153GW.1","url":null,"abstract":"We thank Jan Zalasiewicz and his colleagues for their thoughtful review and critique of our comment on the stratigraphic relevance of the term Anthropocene. We agree that broad and open discussion is useful; however, we wish to clearly iterate that we are not taking a position as flag bearers for the anti-Anthropocene side of the debate. We simply wish to offer our concerns about the formal adoption of the Anthropocene into stratigraphic practice and its growing interplay with the environmental movement at large.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"22 1","pages":"60-61"},"PeriodicalIF":0.0,"publicationDate":"2012-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63678372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}