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Influence of Redox Environment and Aqueous Speciation on Metal Transport in Groundwater:
Published in Herbert E. Allen, E. Michael Perdue, David S. Brown, Metals in Groundwater, 2020
James A. Davis, Douglas B. Kent, Brigid A. Rea, Ann S. Maest, Stephen P. Garabedian
The locations of the tracer-injection tests are shown in Figure 3 as OXIC, MIXED, and SUBOXIC, hereafter referred to as sites O, M, and S. Two of the experiments (at sites M and S) were conducted within an array of densely-instrumented multilevel groundwater samplers (MLS) used in a previous large-scale tracer test [71,77]. This array of samplers (over 600 in number) is located about mid-way between the Otis Air National Guard Base sewage-disposal site and Ashumet Pond, a kettle-hole pond in the outwash plain (Figure 3). Site M was at MLS 10–15 and site S was at MLS 37–12 (see Garabedian [77] for an explanation of MLS numbering). A third experiment was conducted at site O (MLS Ml at well cluster F168), approximately 2.3 km downgradient of sites M and S, where an additional small array of multilevel samplers was installed.
Sediments and Sedimentary Rocks
Published in Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough, Earth Materials, 2019
Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough
When glaciers melt during warm times of the year, streams flow from their tops, bottoms, and sides. These streams carry large sediment loads that include rock flour and lots of coarser material. Eventually this material is deposited as outwash composed of moderately sorted layers of stratified drift, in large outwash plains in front of the glaciers. Seasonal meltwater streams, often braided, are commonly present in outwash plains. The streams deposit coarser materials near their headwaters at the glacier terminus and clays and silts farther away. The largest outwash plains form after some glacial retreat has occurred, so they lie between the present-day glacier terminus and the former terminal moraine. Eventually, a glacier that deposits outwash may disappear, but the distinctive material in the outwash plain is evidence of a glacier’s former presence.
Structures of Coastal Resilience: Adaptive Design for Jamaica Bay, New York
Published in Elizabeth Mossop, Sustainable Coastal Design and Planning, 2018
The Rockaway peninsula and the back bay communities of Jamaica Bay were massively impacted by Hurricane Sandy's surge and extensive flooding in 2012 (Figures 11.2 and 11.3). The bay has been environmentally challenged since its early days as New York City's dumping ground (Moses, 1938; NYCDEP, 2007, 2012). Since the 1970s, the reduction of the marsh island footprints within the bay has rapidly accelerated, likely due to the combined anthropogenic impacts of poor water quality, nutrification, erosion, and sediment starvation (Hartig, 2002). Yet, given its vast scale, Jamaica Bay has the potential to be recast as an impactful ecological, infrastructural, and community asset, becoming an anchor of the region's resiliency. And for the Army Corps of Engineers, the bay presents an incredible design opportunity for exploring the performance of nature-based features, particularly salt marshes, maritime forests, and dunes. Jamaica Bay is a dynamic ecological entity, an estuarine embayment in a post-glacial outwash plain. This sandy and naturally shifting terrain is geologically capable of functioning resiliently both during and after disturbance events. The City College of New York's adaptive design proposals for Jamaica Bay seek to enhance that capability.
Secchi depths in lakes of Cape Cod National Seashore from 1996–2016 and relationships with morphometry, water chemistry, and housing densities
Published in Lake and Reservoir Management, 2018
Stephen M. Smith, Sophia E. Fox, Krista D. Lee, Kelly Medeiros, Holly C. Plaisted
The Cape Cod peninsula (southeastern Massachusetts, USA) extends approximately 50 km into the Atlantic Ocean. Most of the landscape is classified as outwash plain and consists primarily of sand and gravel deposited by streams flowing from the Laurentide glacier as it began to retreat ∼18,000 yr ago. Numerous depressions left behind by melting blocks of ice became freshwater lakes as sea level rose, pushing the groundwater upwards. These waterbodies are known as “kettle ponds” due to their roughly circular shapes. They are hydrologically isolated to the extent that the vast majority have no surface outflows or inflows. Kettle ponds are at the intersection between the land surface and the convex groundwater lenses that float atop seawater in the highly permeable substrate. These sole-source aquifers are entirely dependent upon rainfall for recharge.