Recent studies have shown that permafrost soils in the northern circumpolar region store almost twice as much carbon as the atmosphere. Since soil organic carbon (SOC) pools have large regional and landscape-level variability, detailed SOC inventories from across the northern permafrost region are needed to assess potential remobilization of SOC with permafrost degradation and to quantify the p...

Wind erosion measurements were carried out in Nellis Dunes Recreation Area, southern Nevada, USA. Gross erosion (the total mass of sediment effectively blown away from a surface), gross deposition (the total mass of sediment effectively depositing on a surface) and net erosion (the difference in sediment mass before and after an event) were measured for 1 year, on 17 different types of surfaces...

Visible and near-infrared diffuse reflectance spectroscopy (VIS-NIR) has shown levels of accuracy comparable to conventional laboratory methods for estimating soil properties. Soil chemical and physical properties have been predicted by reflectance spectroscopy successfully on subtropical and temperate soils, whereas soils from tropical agro-forest regions have received less attention, especial...

The immune system of the gut has evolved a number of specific lymphoid structures that contribute to homeostasis in the face of microbial colonization and food-derived antigenic challenge. These lymphoid organs encompass Peyer's patches (PP) in the small intestine and their colonic counterparts that develop in a programed fashion before birth. In addition, the gut harbors a network of lymphoid ...

Mudboils are round to elongate, 1-3 m diameter bare soil patches that form on perennially frozen till. marine clayey silt, colluvium. or other poorly sorted sediments (muds) with significant silt and (or) clay content. In Keewatin these muds have low liquid limirs (<ZM) and limited plasticity indices (<It)%). Natural moisture contents are very near the liquid limit .w thal rhe muds liquefv and ...

Recent stratigraphic studies in central Alaska have yielded the unexpected finding that there is little evidence for full-glacial (late Wisconsin) loess deposition. Because the loess record of western Alaska is poorly exposed and not well known, we analyzed a core from Zagoskin Lake, a maar lake on St. Michael Island, to determine if a full-glacial eolian record could be found in that region. P...

A 31 year record of ∼44,000 nitrate analyses in ∼11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N ≥ 10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hecta...

A collaborative virtual geographic environment (CVGE) is a 3-D, distributed, and graphical world representing and simulating geographic phenomena and processes to enable geographically distributed users to explore geoproblems and theories and generate hypotheses, and to support geomodel building and validation and collaborative ecological planning. This chapter reports an approach to establishi...

Piezocone penetration tests with dissipation phases are particularly useful for geotechnical site characterization. They also provide three independent readings with depth from a single sounding as well as time-rate information. In past investigations, only silty sands with specific silt content have been tested and complete sets of tests have not been conducted to evaluate the influence of dif...