Skip to main content
Advanced Search

Filters: Tags: carbon isotope analysis (X) > Types: OGC WFS Layer (X)

5 results (12ms)   

View Results as: JSON ATOM CSV
thumbnail
Coastal wetlands are major global carbon sinks, however, they are heterogeneous and dynamic ecosystems. To characterize spatial and temporal variability in a New England salt marsh, static chamber measurements of greenhouse gas (GHG) fluxes were compared among major plant-defined zones (high marsh dominated by Distichlis spicata and a zone of invasive Phragmites australis) during 2013 and 2014 growing seasons. Two sediment cores were collected in 2015 from the Phragmites zone to support previously reported core collections from the high marsh sites (Gonneea and others 2018). Collected cores were up to 70 cm in length with dry bulk density ranges from 0.04 to 0.33 grams per cubic centimeter and carbon content 22.4%...
thumbnail
The San Juan Bay Estuary, Puerto Rico, contains mangrove forests that store significant amounts of organic carbon in soils and biomass. There is a strong urbanization gradient across the estuary, from the highly urbanized and clogged Caño Martin Peña in the western part of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part with limited urbanization. We collected sediment cores to determine carbon burial rates and vertical sediment accretion from five sites in the San Juan Bay Estuary. Cores were radiometrically-dated using lead-210 and the Plum age model. Sites had soil C burial rates ranging from 50 grams per meter squared per year (g m-2...
thumbnail
Sediment cores were collected in Great Dismal Swamp National Wildlife Refuge in November, 2017 to advance understanding of climate- and land-management driven changes in vegetation, hydrology, and fire regimes. Radiocarbon dates were obtained from samples in two cores (GDS-519-3-21-2017 and GDS-520-3-21-2017) to generate age models for the cores. Bulk sediment samples, charcoal, plant macrofossils, and pollen residue were selected at the USGS in Reston, Virginia and submitted to Beta Analytic, Inc. and the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) laboratories for radiocarbon dating. Those laboratories provided both radiocarbon ages and stable carbon isotope (delta 13C) results, which can be...
thumbnail
This database contains a comprehensive inventory of geologic (coral, coral reef, limestone, and sediment) cores and samples collected, analyzed, published, and/or archived by, or in collaboration with, the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC). The SPCMSC Geologic Core and Sample Database includes geologic cores and samples collected beginning in the 1970s to present day, from study sites across the world. This database can be accessed through the CoreViewer 3.0 ArcOnline web mapping application, linked below. A copy of the data can also be downloaded from the web mapping application and the metadata is accessible through a link in the header of the application, as...
Types: Application, Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Alabama, Atlantic Ocean, Bahamas, Belize, Brazil, All tags...
thumbnail
Old Faithful Geyser in the Upper Geyser Basin of Yellowstone National Park is one of the best studied geysers in the world. Under research permit YELL-SCI-8030, samples from 13 silicified tree remnants were collected adjacent to the Old Faithful Geyser cone in April and November 2019. The silicified wood samples were dated using the radiocarbon (14C) method and were analyzed by scanning electron microscope (SEM) to determine the extent of wood silicification. This study was conducted in order to provide new information on the geyser’s past decadal to centennial eruptive activity. Understanding Old Faithful’s past could provide a baseline for understanding future changes in its eruption intervals.