Mercury (Hg) can reach toxic concentrations in aquatic habitats, sometimes as a consequence of human activity. Mercury can have deleterious effects, particularly in piscivorous mammals in which it bioaccumulates. Furs from trapper-provided female otter (Lontra canadensis) carcasses in Nova Scotia were analyzed for total Hg. Concentrations of total Hg in fur samples averaged 25 µg/g dry weight, ...

Ground-penetrating radar (GPR) is becoming a commonly applied technique in geomorphology. However, its use in the study of subglacial bedforms has yet to be fully explored and exploited. This paper presents the results of a GPR feasibility study conducted on a drumlinized terrain in Cumbria, UK, where five drumlins were investigated using multiple radar antenna frequencies. The site was selecte...

In this paper, we trace the route by which genetics could ultimately connect to issue attitudes and suggest that central to this connection are chronic dispositional preferences for mass-scale social rules, order, and conduct—what we label political ideology. The need to resolve bedrock social dilemmas concerning such matters as leadership style, protection from outgroups, and the degree to whi...

[1] We explored the dependence of experimental bedrock erosion rate on shear stress, bed load sediment flux, alluvial bed cover, and evolving channel morphology. We isolated these variables experimentally by systematically varying gravel sediment flux Qs and water discharge Qw in a laboratory flume, gradually abrading weak concrete “bedrock.” All else held constant, we found that (1) erosion ra...

A flight of marine terraces along the central California coastline provides a unique setting for the study of topographic evolution. Wavecut platforms manfled by 2-6 m of marine terrace cover deposits are separated by10-50 m tall decaying sea cliffs. Palcocliff edges become more rounded with age, yet the details of the profries and frequent bedrock exposure on the upper slopes imply weatheringl...

Natural bedrock rivers flow in self-formed channels and form diverse erosional morphologies. The parameters that collectively define channel morphology (e.g. width, slope, bed roughness, bedrock exposure, sediment size distribution) all influence river incision rates and dynamically adjust in poorly understood ways to imposed fluid and sediment fluxes. To explore the mechanics of river incision...

This field trip provides an opportunity to reevaluate the processes responsible for some subglacial bedrock erosion features in northern Ohio. Beginning in the 1830s, quarrying operations on Kelleys Island, OH, have uncovered several giant grooves on the bedrock surface. One such groove remains for investigation today. There is agreement that these features were formed mainly in a subglacial en...

Relationships between cataclysmic flood-generated landforms and flood hydraulics were investigated along Box Canyon, an 11 km long bedrock gorge of the lower Big Lost River. Geomorphic mapping along Box Canyon indicates that a cataclysmic flood completely inundated the gorge, resulting in large-scale erosional and depositional features on the adjacent basalt upland. Step-backwater hydraulic mod...

Nonlinear relations between rain input and hillslope outflow are common observations in hillslope hydrology field studies. In this paper we use percolation theory to model the threshold relationship between rainfall amount and outflow and show that this nonlinear relationship may arise from simple linear processes at the smaller scale. When the rainfall amount exceeds a threshold value, the und...