Publications

No abstract available.

The Lake Michigan outer nearshore zone (water depths ≈5 to 25 m) off Illinois Beach State Park is subjected to a spectrum of wave conditions, including those generated by major storms. Only under these major storm conditions is there a realistic potential for wave-lakebed interaction (and associated wind-driven currents) to cause a significant net modification to the outer nearshore...

We have constructed a sediment budget for the southern Lake Michigan basin for sand and for mud during three time periods: the past 100, 5,000, and 10,000 years. For the modern (100-year) sediment budget, accountable sediment sources add up to 93 percent of the calculated sinks. The mud budget has a source deficit of about 40%, probably due to errors in mud:sand ratios and (or) to other...

An 18 month simulation of circulation was conducted in Massachusetts Bay, a roughly 35 m deep, 100??50 km embayment on the northeastern shelf of the United States. Using a variant of the Blumberg-Mellor (1987) model, it was found that a continuous 18 month run was only possible if the velocity field was Shapiro filtered to remove two grid length energy that developed along the open...

Two episodes of meltwater influx from glacial Lake Agassiz are recorded as prominent sedimentologic, isotopic, magnetic, and faunal signatures in southern Lake Michigan profundal sediments. As a tributary to the main path of eastward Lake Agassiz flow, southern Lake Michigan recorded only the largest, catastrophic discharges. The distinctive Wilmette Bed, a massive gray mud that...

Time-series measurements of current velocity, optical attenuation and surface wave intensity obtained during the Sediment Transport Events on Shelves and Slopes (STRESS) experiments, combined with shipboard measurements of conductivity, temperature and optical attenuation obtained during the Shelf Mixed Layer Experiment (SMILE), provide a description of the sediment concentration field...

Linear alkylbenzenes (LABs), coprostanol and epi-coprostanol, were detected in sediment trap and bottom sediment samples at the Deep Water Dump Site 106 located 185 km off the coast of New Jersey, in water depths from 2400 to 2900 m. These findings clearly indicate that organic pollutants derived from dumped sludge are transported through the water column and have accumulated on the deep...

The bathymetry is controlled by the underlying bedrock. Bedrock comprises Silurian dolomite and Devonian limestone and shale. Quaternary sediment, 10 to 40 m thick, overlies bedrock. From Waukegan, Illinois, south to Indiana Harbor, the bottom is floored by till, sand, pebbles, and cobbvles. The lake floor is erosional or nondepositional where till or gravel-cobble pavement is exposed...

Streamlined, oval-shaped, oriented topographic highs in Massachusetts Bay are identified as the erosional remnants of drumlins. The topographic highs correlate with outlines of lag gravel deposits on the sea floor and both the highs and lag gravel seafloor footprint have a distinct east-southeast long axis trend. This trend is similar to the preferred orientation of the long axes of...

Rock-magnetic measurements of sediment cores from the Academician Ridge region of Lake Baikal, Siberia show variations related to Late Quaternary climate change. Based upon the well-dated last glacial-interglacial transition, variations in magnetic concentration and mineralogy are related to glacial-interglacial cycles using a conceptual model. Interglacial intervals are characterized by...

The need for earth science has never been more paramount. The devastating flooding of the Mississippi River this past year, strikingly portrayed on the cover and discussed in detail in this report (p. 37-42), was a sobering reminder of nature's elemental power. As a Nation, we face many environmental and economic challenges, such as natural hazards, that can be addressed effectively only...

No abstract available.