John Crusius

Seasonal and spatial variabilities in northern Gulf of Alaska surface water iron concentrations driven by shelf sediment resuspension, glacial meltwater, a Yakutat eddy, and dust

Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016GB005493/abstract): Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate depletion began. Sediment resuspension during winter and spring storms generated high “total dissolvable Fe” (TDFe) concentrations of ~1000 nmol kg−1 along the entire continental shelf, which decreased beyond the shelf break. In July, high...

Categories: Publication; Types: Citation; Tags: Glaciers and Permafrost, National CASC, Rivers, Streams and Lakes, Sea-Level Rise and Coasts, Water, Coasts and Ice

As glaciers melt from climate change, their contents – namely, large quantities of freshwater, sediment, and nutrients – are slowly released into coastal ecosystems. This project addressed the impacts of melting glaciers on coastal ecosystems in the Copper River region of the Gulf of Alaska, which is home to several commercially important fisheries. Researchers examined how glacial melting is altering the amount and timing of freshwater that enters the Gulf of Alaska from the Copper River. They also investigated the source and amount of two nutrients, iron and nitrate, dissolved in the water. As a complementary piece of the study, researchers tested the relationship between nutrient levels, plankton populations,...

Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 2009, CASC, Completed, Glaciers and Permafrost, Glaciers and Permafrost, All tags... Gulf of Alaska, Iron, National CASC, National CASC, Projects by Region, Rivers, Streams and Lakes, Rivers, Streams and Lakes, Sea-Level Rise and Coasts, Sea-Level Rise and Coasts, Water, Coasts and Ice, Water, Coasts and Ice, climate change, melting glaciers, Fewer tags

Coastal Groundwater Chemical Data from the North and South Shores of Long Island, New York

Groundwater data were collected in the spring and fall of 2008 from three sites representing different geological settings and biogeochemical conditions within the surficial glacial aquifer of Long Island, NY. Investigations were designed to examine the extent to which average vadose zone thickness in contributing watersheds controlled biogeochemical conditions and processes, including dissolved oxygen concentration (DO), oxidation-reduction potential (Eh), dissolved organic carbon concentration (DOC), and microbial dinitrogen (N2) production. Greatest N2 production was observed at the south shore of Long Island, which is characterized by a thin vadose zone, low DO and Eh, and relatively high DOC. Limited N2 production...

Categories: Data; Types: Citation; Tags: Geochemistry, Great South Bay, Hydrogeology, Long Island Sound, Long Island, NY, United States, All tags... Manhasset Bay, Northport Harbor, Northport, NY, United States, Patchogue, NY, United States, Port Washington, NY, United States, Water Resources, climate change, denitrification, dissolved organic carbon, dissolved oxygen, environment, excess air, geoscientificInformation, groundwater, groundwater discharge, hydrogeology, membrane inlet mass spectrometry (MIMS), nitrate, oxygen content (water), recharge temperature, salinity, tritium analysis, vadose zone thickness, water chemistry, water pH, Fewer tags

Gulf of Alaska Shelf and Slope Iron and Nitrate Data, Copper River Region, 2010

These are data from cruises carried out in April, May and July 2010 from the Copper River (AK) mouth to beyond the shelf break, approximately 150 km from shore. The focus of the dataset is the iron (Fe) data, intended to help infer the processes controlling concentrations of Fe. The data include concentrations of total dissolvable Fe (TDFe), dissolved Fe (dFe), nitrate, and salinity, temperature and fluorescence data (CTD) as background. This also includes sea surface height deviation data for a two month interval when a Yakutat eddy passed by the sampling site. Also included is a simple 1-dimensional numerical model used to simulate the the April DFe data assuming a DFe flux from shelf sediments, horizontal transport...

Categories: Data; Tags: Alaska, Biogeochemical cycles, Copper River, Gulf of Alaska, Iron, All tags... Marine Geology, Nitrate, Nutrient cycling, Oceans, Suspended solids, Trace elements, USGS Science Data Catalog (SDC), Water Quality, Fewer tags