122 research outputs found
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Rainbow Beach Sediment Grain Size Analysis, Northampton, Massachusetts
No full textSee Readme file.This dataset was prepared by Brian Yellen, a research assistant professor in the Department of Earth, Geographic, and Climate Sciences at the University of Massachusetts Amherst. Dr. Yellen worked in conjunction with Melissa Grader of the USFWS and colleagues to conduct the associated field sampling. This report provides information related to the substrate grain size at surveyed locations on Rainbow Beach on the Connecticut River in Northampton, MA (42.322125, -72.584928). This location is a known breeding site of the endangered puritan tiger beetle (PTB), Ellipsoptera puritana
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Dam Impoundments Sediment Mass – Tributaries to the Hudson River
No full textThe README file for this data is included in the downloadable .zip file.This repository contains data from sediment cores collected during 2017-2018 from 17 impoundments that are located on tributaries to the tidal portion of the Hudson River as part of a larger NERRs collaborative project entitled Dams and Sediment on the Hudson (DaSH). A companion dataset that contains sediment core data from Hudson tidal marshes is archived at UMass Scholarworks data repository. Sediment cores collected from impoundments behind dams were recovered via piston push coring, which tends to minimize compaction and be representative of true sediment thicknesses. The general workflow for cores included (1) splitting; (2) Itrax XRF scanning; (3) subsampling cores ~10 cm spacing; (4) drying and burning samples for percent water, organic, and mineral (Dean, 1974). Combusted samples were gently disaggregated with mortar and pestle and analyzed for grain size on a Coulter Laser Particle Size Analyzer. Basal sediments were identified by low organic content and a contrast in grainsize or sediment texture with overlying pond sediment. Sediment age was constrained by the construction date of the corresponding dam, when that information was available, and by 137Cs chronology when absent. The small sediment masses present in most of these dams relative to expected masses based on regional sediment yield is representative of the small aggregate trapping of sediment by legacy mill dams in the Northeast US, highlighted in the manuscript “Watershed sediment supply and potential impacts of dam removals for an estuary,” submitted to Estuaries and Coasts in March, 2020.This work was sponsored by the National Estuarine Research Reserve System Science Collaborative, which is funded by the National Oceanic and Atmospheric Administration and managed by the University of Michigan Water Center (NAI4NOS4190145). This project was supported by Grant or Cooperative Agreement No. G12AC00001 from the U.S. Geological Survey and Department of Interior Northeast Climate Adaptation Science Center fellowships for Caroline Ladlow and Brian Yellen
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Hudson River Estuary Tidal Marsh Sediment Data
No full textThe README file for this data is included in the downloadable .zip file.This repository contains data from sediment cores collected at six tidal wetland complexes that are located within the Hudson River Estuary. The sites include Stockport Marsh, Esopus Delta, Tivoli North Bay, Tivoli South Bay, Vanderburgh Cove, and Iona Island Marsh. A variety of core collection tools and methods were used to collect uncompacted records, including gouge coring, Russian peat coring, and piston push coring, with the method determined by coring environment. The general workflow for cores included (1) splitting; (2) Itrax XRF scanning; (3) subsampling cores ~10 cm spacing; (4) drying and burning samples for percent water, organic, and mineral content. Gamma spectroscopy was used to identify down-core profiles of 137Cs and 210Pb in at least one representative core from each site. Relative abundance and onset of heavy metals zinc (Zn) and lead (Pb) as recorded in X-ray Flourecense (XRF) data were used as additional supportive age constraint in cores. Collectively, data from these cores provide evidence within the tidal freshwater Hudson River for rapid accretion within anthropogenic tidal freshwater wetlands relative to those that developed prior to the industrial era.This work was sponsored by the National Estuarine Research Reserve System Science Collaborative, which is funded by the National Oceanic and Atmospheric Administration and managed by the University of Michigan Water Center (NAI4NOS4190145). This project was supported by Grant or Cooperative Agreement No. G12AC00001 from the U.S. Geological Survey and Department of Interior Northeast Climate Adaptation Science Center fellowships for Caroline Ladlow and Brian Yellen
sj-pdf-1-hol-10.1177_09596836231225725 – Supplemental material for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene
No full textSupplemental material, sj-pdf-1-hol-10.1177_09596836231225725 for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene by Berry L Williams, Stephen J Burns, Nick Scroxton, Laurie R Godfrey, Benjamin H Tiger, Brian Yellen, Robin R Dawson, Peterson Faina, David McGee and Lovasoa Ranivoharimanana in The Holocene</p
sj-pdf-3-hol-10.1177_09596836231225725 – Supplemental material for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene
No full textSupplemental material, sj-pdf-3-hol-10.1177_09596836231225725 for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene by Berry L Williams, Stephen J Burns, Nick Scroxton, Laurie R Godfrey, Benjamin H Tiger, Brian Yellen, Robin R Dawson, Peterson Faina, David McGee and Lovasoa Ranivoharimanana in The Holocene</p
Turbidity Hysteresis in an Estuary and Tidal River Following an Extreme Discharge Event
No full text© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ralston, D. K., Yellen, B., Woodruff, J. D., & Fernald, S. Turbidity hysteresis in an estuary and tidal river following an extreme discharge event. Geophysical Research Letters, 47(15), (2020): e2020GL088005, doi:10.1029/2020GL088005.Nonlinear turbidity‐discharge relationships are explored in the context of sediment sourcing and event‐driven hysteresis using long‐term (≥12‐year) turbidity observations from the tidal freshwater and saline estuary of the Hudson River. At four locations spanning 175 km, turbidity generally increased with discharge but did not follow a constant log‐log dependence, in part due to event‐driven adjustments in sediment availability. Following major sediment inputs from extreme precipitation and discharge events in 2011, turbidity in the tidal river increased by 20–50% for a given discharge. The coherent shifts in the turbidity‐discharge relationship along the tidal river over the subsequent 2 years suggest that the 2011 events increased sediment availability for resuspension. In the saline estuary, changes in the sediment‐discharge relationship were less apparent after the high discharge events, indicating that greater background turbidity due to internal sources make event‐driven inputs less important in the saline estuary at interannual time scales.This work was sponsored by the National Estuarine Research Reserve System Science Collaborative, funded by the National Oceanic and Atmospheric Administration and managed by the University of Michigan Water Center (NAI4NOS4190145), with additional support to Yellen and Woodruff from USGS Cooperative Agreement No. G19AC00091
sj-pdf-2-hol-10.1177_09596836231225725 – Supplemental material for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene
No full textSupplemental material, sj-pdf-2-hol-10.1177_09596836231225725 for A speleothem record of hydroclimate variability in northwestern Madagascar during the mid-late Holocene by Berry L Williams, Stephen J Burns, Nick Scroxton, Laurie R Godfrey, Benjamin H Tiger, Brian Yellen, Robin R Dawson, Peterson Faina, David McGee and Lovasoa Ranivoharimanana in The Holocene</p
Executive Pay – a career perspective
No full textThis paper argues that the rise in directors’ remuneration in the UK over recent years has been, to a large extent, an unintended consequence of institutional change in the governance arrangements of UK companies. The increase in disclosure regarding the detail of what directors are paid and the adoption of transparent processes by which directors’ remuneration is determined have combined to produce an outcome whereby the top management teams of large publicly held companies are able to command an ever increasing portion of the quasirent (surplus after running costs) earned by those companies. It is also true that a shift in shareholder attitudes has brought about an increased emphasis on shareholder value which, in turn, has encouraged the uptake of payment-by-results arrangements for the remuneration of directors. These have made the reward stream more ‘risky’ as far as the individual director is concerned and, in recognition of this and to compensate for risk aversion, the actuarial value of remuneration has increased. In a more general setting, runaway labour costs would be expected to be held in check by competitive forces in the product market or, in the face of diminishing profitability, by the market for corporate control, whereby underperforming companies are vulnerable to takeover. But while remuneration payouts to directors are large by many measures, they do not present a significant issue for the UK’s larger companies. For reasons explored below, the upward pressure on directors’ remuneration can be expected to continue. Some of the less desirable features of this trend (pay without performance, etc.) could in part, be remedied by a move to Career Shares – long term incentives which cannot be cashed out on vesting but must be held until some considerable time after the director has demitted office. The following section of the paper attempts to flesh out this argument, starting with an examination of Chief Executive Officer (CEO) pay trends in the FTSE-350
You didn't want me when I wanted
No full textGift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]B flat major [key]Valse moderato [tempo]Popular song [form/genre]Birdcage ; Milton Charles (photograph) [illustration]Publisher's advertisement on back cover [note
Watershed suspended sediment supply and potential impacts of dam removals for an estuary
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ralston, D. K., Yellen, B., & Woodruff, J. D. Watershed suspended sediment supply and potential impacts of dam removals for an estuary. Estuaries and Coasts, (2021), https://doi.org/10.1007/s12237-020-00873-3.Observations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity.This work was sponsored by the National Estuarine Research Reserve System Science Collaborative, which is funded by the National Oceanic and Atmospheric Administration and managed by the University of Michigan Water Center (NAI4NOS4190145). Additional support for participating graduate and undergraduates was provided by the Northeast Climate and Adaptation Center and the Hudson River Fund. Additional support for DKR was provided by the Hudson River Foundation (Grant No. 003/19A). Data from sediment cores that were collected in association with this manuscript are archived here: https://doi.org/10.7275/dh3v-0x33
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