Filters: Tags: lead-210 (X)
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Specific activities of cesium-137 (half life = 30.17 years), lead-210 (half life = 22.3 years), radium-226 (half life = 1,600 years), thorium-234 (half life = 24.1 days), and potassium-40 (half life = 1.277 billion years) in disintegrations per minute per gram (dpm/g) were determined for the Lake Lanier cores. The laboratory errors (plus or minus) and the critical levels are included for each sample.
Nineteen sediment cores were collected from five salt marshes on the northern shore of Cape Cod where previously restricted tidal exchange was restored to part of the marshes. Cores were collected in duplicate from two locations within each marsh complex: one upstream and one downstream from the former tidal restriction (typically caused by an undersized culvert or a berm). The unaltered, natural downstream sites provide a comparison against the historically restricted upstream sites. The sampled cores represent a chronosequence of restoration occurring between 2001–10. Collected cores were up to 168 cm in length with dry bulk density ranging from 0.04 to 2.62 grams per cubic centimeter and carbon content 0.12 %...
Categories: Data;
Tags: Barnstable County (606927),
Bass Creek (617465),
Boat Meadow River (616844),
Cape Cod (606914),
Cape Cod Canal (619536),
The sustainability of coastal wetlands largely hinges on their ability to accrue elevation capital at a rate that equals or exceeds relative sea-level rise. A better understanding of these processes is needed to accurately assess the sustainability of these landscapes, and to predict their response to restoration measures such as sediment delivery through river diversions.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Barataria basin,
Gulf of Mexico,
Louisiana,
USGS Science Data Catalog (SDC),
[u'Ecology',
Sediment cores were collected from three sites within the Plum Island Ecosystems Long-Term Ecological Research (PIE-LTER) domain in Massachusetts to obtain estimates of long-term marsh decomposition and evaluate shifts in the composition and reactivity of sediment organic carbon in disturbed marsh environments. Paired sediment cores were collected from three sites on the marsh platform and from three ponds; these cores were about 100 and 50 centimeters in length, respectively. The marsh sites had similar elevations, at about 1.41 to 1.51 meters relative to the North American Vertical Datum of 1988, and similar salt marsh grass communities, dominated by Spartina patens, S. alterniflora, and Distichlis spicata. Permanently...
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