Environmental Studies Program: Recent submissions
Now showing items 21-40 of 62
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The under-ice microbiome of seasonally frozen lakes
(Association for the Sciences of Limnology and Oceanography, 2013-10-21)Compared to the well-studied open water of the “growing” season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange ... -
Iron clad wetlands: Soil iron-sulfur buffering determines coastal wetland response to salt water incursion
(American Geophysical Union, 2014-10-25)Coastal freshwater wetland chemistry is rapidly changing due to increased frequency of salt water incursion, a consequence of global change. Seasonal salt water incursion introduces sulfate, which microbially reduces to ... -
The Lotic Intersite Nitrogen Experiments: an example of successful ecological research collaboration
(University of Chicago Press, 2016-05-06)Collaboration is an essential skill for modern ecologists because it brings together diverse expertise, viewpoints, and study systems. The Lotic Intersite Nitrogen eXperiments (LINX I and II), a 17-y research endeavor ... -
Land occupations and deforestation in the Brazilian Amazon
(Elsevier, 2016-07-01)Researchers are increasingly interested in understanding the impact of contentious social processes on land change. In the Brazilian Amazon, there are often contentious interactions between landholders defending private ... -
Using an Analytic Hierarchy Process Approach to Prioritize Public Policies Addressing Family Farming in Brazil
(Elsevier, 2016-02-01)In Brazil, some see intensive, large-scale production of sugarcane-based ethanol, based on a model of capital and land concentration, as a threat to the survival of family farming. Family farmers are increasingly under ... -
Unlocking the Doors to the Worlds of Guaman Poma and His Nueva corónica
(University of Chicago Press, 2015)Felipe Guaman Poma de Ayala’s handwritten illustrated book, Nueva corónica y buen gobierno, from 1615—honored by UNESCO as a “Memory of the World” item—rewrote Andean history in accordance with his goals of reforming Spanish ... -
Guano Inside-Out
(H-Net: Humanities and Social Sciences Online, 2016-02) -
Oxidative elemental cycling under the low O2 Eoarchean atmosphere
(Nature Publishing Group, 2016-02-01)The Great Oxidation Event signals the first large-scale oxygenation of the atmosphere roughly 2.4 Gyr ago. Geochemical signals diagnostic of oxidative weathering, however, extend as far back as 3.3–2.9 Gyr ago. 3.8–3.7 Gyr ... -
Ethanol plant location and intensification vs. extensification of corn cropping in Kansas
(Elsevier, 2014-09)Farmers' cropping decisions are a product of a complex mix of socio-economic, cultural, and natural environments in which factors operating at a number of different spatial scales affect how farmers ultimately decide to ... -
ICESat measurements reveal complex pattern of elevation changes on Siple Coast ice streams, Antarctica
(American Geophysical Union, 2005-12-03)We compare ICESat data (2003–2004) to airborne laser altimetry data (1997–98 and 1999–2000) to monitor surface changes over portions of Van der Veen (VdVIS), Whillans (WIS) and Kamb ice streams (KIS) in the Ross Embayment ... -
Bed radar reflectivity across the north margin of Whillans Ice Stream, West Antarctica, and implications for margin processes
(International Glaciological Society, 2006-01-01)Surface-based ice-penetrating radar profiles were made across the active north margin (the Snake) of the upper part of Whillans Ice Stream (formerly Ice Stream B, branch B2), West Antarctica, at three locations. Low frequency ... -
Controls on advance of tidewater glaciers: results from numerical modeling applied to Columbia Glacier
(American Geophysical Union, 2007-07-11)A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance ... -
Subglacial topography and geothermal heat flux: potential interactions with drainage of the Greenland ice sheet
(American Geophysical Union, 2007-06-05)[1] Many of the outlet glaciers in Greenland overlie deep and narrow trenches cut into the bedrock. It is well known that pronounced topography intensifies the geothermal heat flux in deep valleys and attenuates this flux ... -
Fracture propagation as means of rapidly transferring surface meltwater to the base of glaciers
(American Geophysical Union, 2007-01-07)1] Propagation of water-filled crevasses through glaciers is investigated based on the linear elastic fracture mechanics approach. A crevasse will penetrate to the depth where the stress intensity factor at the crevasse ... -
Modeling dynamic controls on ice streams: a Bayesian statistical approach
(International Glaciological Society, 2008-12-05)Our main goal is to exemplify the study of ice-stream dynamics via Bayesian statistical analysis incorporating physical, though imperfectly known, models using data that are both incomplete and noisy. The physical–statistical ... -
Intermittent thinning of Jakobshavn Isbræ, West Greenland, since the Little Ice Age
(International Glaciological Society, 2008-05-05)Rapid thinning and velocity increase on major Greenland outlet glaciers during the last two decades may indicate that these glaciers became unstable as a consequence of the Jakobshavn effect (Hughes, 1986), with terminus ... -
Surface roughness over the northern half of the Greenland Ice Sheet from airborne laser altimetry
(American Geophysical Union, 2009-06-05)Surface roughness, defined as the standard deviation of small-scale elevation fluctuations from the linear trend over 0.5 km, can be estimated from high-resolution airborne laser altimetry. Here we present results for the ... -
Basal melt rates beneath Whillans Ice Stream, West Antarctica
(International Glaciological Society, 2010-08-05)Basal water lubricates and enables the fast flow of the West Antarctic ice streams which exist under low gravitational driving stress. Identification of sources and rates of basal meltwater production can provide insight ... -
A physically based calving model applied to marine outlet glaciers and implications for the glacier dynamics
(International Glaciological Society, 2010-11-05)We present results from numerical ice-flow models that include calving criteria based on penetration of surface and basal crevasses, which in turn is a function of longitudinal strain rates near the glacier front. The ... -
The response of Petermann Glacier to large calving events and its future stability in the context of atmospheric and oceanic warming
(International Glaciological Society, 2012-11-05)This study assesses the impact of a large 2010 calving event on the current and future stability of Petermann Glacier, Greenland, and ascertains the glacier’s interaction with different components of the climate and ocean ...
