Roden-Tice M.K.,Center for Earth and Environmental Science |
Eusden J.D.,Bates College |
Wintsch R.P.,Indiana University Bloomington
Geomorphology | Year: 2012
Apatite fission track (AFT) ages in samples collected along the 5000 foot relief (1500m) exposed at Mt. Washington in the Presidential Range of New Hampshire are used to constrain the Cretaceous cooling history of this area in the northern Appalachians. Nine AFT ages for samples of the Littleton and Rangeley formations collected along this profile range in age from ~150Ma at the highest elevations of ~1900m to ~100Ma at the base (~500m). Thermal histories based on these results and on model time-temperature histories based on the distribution of fission track lengths in the higher elevations samples show three stages of cooling, from 1.5-2.0°C/m.y. (170-130Ma) to 0.2°C (130-65Ma), to ~0.6°C/m.y. (65Ma to the present). In contrast, the thermal history calculated for the lower elevations sample shows cooling delayed until ~120Ma at ~2°C/m.y. (120-100Ma), followed by monotonic cooling of ~0.6°C/m.y. from 100Ma to the present. The convergence of these histories from high, intermediate, and low elevations suggests a common cooling history independent of elevation differences of >1km. Structural/tectonic explanations for this thermal convergence are implausible, and we conclude that the most likely explanation for the common cooling history across >1km of relief is that the relief was established by the end of the Cretaceous and has persisted with steady-state topography through the Tertiary to the present. The AFT results are consistent with an earlier relief method study employing 40Ar/ 39Ar muscovite cooling ages. Geothermal gradients calculated from the results of both studies yield ~40°C/km suggesting that this gradient persisted throughout Permian and Mesozoic times. © 2011 Elsevier B.V..
Gervich C.D.,Center for Earth and Environmental Science |
Pitt D.R.,Virginia Commonwealth University
Journal of Environmental Studies and Sciences | Year: 2014
Preference power allocations are allowances of electricity produced at government-owned power-generating facilities that are designated for sale to specific users at below-market rates. The Niagara Preference Power Program (NPPP) provides power to 51 municipally and/or cooperatively owned rural electric providers in the New York State. In this research, we use the analytical framework of the three E's of sustainability-ecology, economy, and social equity-to explore how the NPPP influences municipal efforts to conserve energy, integrate energy planning into community development, and advance social equity among community members. Our survey of municipal officials in NPPP communities and follow-up semi-structured interviews indicate that the NPPP offers significant benefits to participating communities. Benefits include low electric rates and high levels of energy literacy among municipal leaders. Simultaneously, preference power may complicate economic development and energy conservation initiatives. Several communities involved in this study have developed techniques for overcoming these obstacles, such as creative rate structures and approaches to the promotion and implementation of energy conservation efforts. Consequently, these select municipalities challenge deeply held assumptions about the motivations that underlie energy conservation efforts and effective communication about the value of conservation behaviors in situations with weak, indirect, and invisible financial incentives. © 2014 AESS.
Schultz R.,Mississippi State University |
Schultz R.,Center for Earth and Environmental Science |
Dibble E.,Mississippi State University
Hydrobiologia | Year: 2012
Biological invasions of aquatic plants (i. e., macrophytes) are a worldwide phenomenon, and within the last 15 years researchers have started to focus on the influence of these species on aquatic communities and ecosystem dynamics. We reviewed current literature to identify how invasive macrophyte species impact fishes and macroinvertebrates, explore how these mechanisms deviate (or not) from the accepted model of plant-fish interactions, and assess how traits that enable macrophytes to invade are linked to effects on fish and macroinvertebrate communities. We found that in certain instances, invasive macrophytes increased habitat complexity, hypoxia, allelopathic chemicals, facilitation of other exotic species, and inferior food quality leading to a decrease in abundance of native fish and macroinvertebrate species. However, mechanisms underlying invasive macrophyte impacts on fish and macroinvertebrate communities (i. e., biomass production, photosynthesis, decomposition, and substrate stabilization) were not fundamentally different than those of native macrophytes. We identified three invasive traits largely responsible for negative effects on fish and macroinvertebrate communities: increased growth rate, allelopathic chemical production, and phenotypic plasticity allowing for greater adaptation to environmental conditions than native species. We suggest that information on invasive macrophytes (including invasive traits) along with environmental data could be used to create models to better predict impacts of macrophyte invasion. However, effects of invasive macrophytes on trophic dynamics are less well-known and more research is essential to define system level processes. © 2011 Springer Science+Business Media B.V.
Oswald E.M.,University Corporation for Atmospheric Research |
Dupigny-Giroux L.-A.,University of Vermont |
Leibensperger E.M.,Center for Earth and Environmental Science |
Poirot R.,Vermont Agency of Natural Resources |
Merrell J.,Vermont Agency of Natural Resources
Atmospheric Environment | Year: 2015
The goal of this study is to better understand the linkages between the climate system and surface-level ozone concentrations in the Northeastern U.S. We focus on the regularity of observed high ozone concentrations between May 15 and August 30 during the 1993-2012 period. The first portion of this study establishes relationships between ozone and meteorological predictors. The second examines the linkages between ozone and large-scale teleconnections within the climate system. Statistical models for each station are constructed using a combination of Correlation Analysis, Principal Components Analysis and Multiple Linear Regression. In general, the strongest meteorological predictors of ozone are the frequency of high temperatures and precipitation and the amount of solar radiation flux. Statistical models of meteorological variables explain about 60-75% of the variability in the annual ozone time series, and have typical error-to-variability ratios of 0.50-0.65. Teleconnection patterns such as the Arctic Oscillation, Quasi-Biennial Oscillation and Pacific Decadal Oscillation are best linked to ozone in the region. Statistical models of these patterns explain 40-60% of the variability in the ozone annual time series, and have a typical error-to-variability ratio of 0.60-0.75. © 2015 The Authors.
Rayburn J.A.,Suny New Paltz |
Cronin T.M.,U.S. Geological Survey |
Franzi D.A.,Center for Earth and Environmental science |
Knuepfer P.L.K.,Binghamton University State University of New York |
Willard D.A.,U.S. Geological Survey
Quaternary Research | Year: 2011
Radiocarbon-dated sediment cores from the Champlain Valley (northeastern USA) contain stratigraphic and micropaleontologic evidence for multiple, high-magnitude, freshwater discharges from North American proglacial lakes to the North Atlantic. Of particular interest are two large, closely spaced outflows that entered the North Atlantic Ocean via the St. Lawrence estuary about 13,200-12,900cal yr BP, near the beginning of the Younger Dryas cold event. We estimate from varve chronology, sedimentation rates and proglacial lake volumes that the duration of the first outflow was less than 1yr and its discharge was approximately 0.1Sv (1 Sverdrup=106m3 s-1). The second outflow lasted about a century with a sustained discharge sufficient to keep the Champlain Sea relatively fresh for its duration. According to climate models, both outflows may have had sufficient discharge, duration and timing to affect meridional ocean circulation and climate. In this report we compare the proglacial lake discharge record in the Champlain and St. Lawrence valleys to paleoclimate records from Greenland Ice cores and Cariaco Basin and discuss the two-step nature of the inception of the Younger Dryas. © 2010 University of Washington.