St. Petersburg, Fla. – A newly developed computer model holds the promise of helping scientists track and predict where oil will go after a spill, sometimes years later. U.S. Geological Survey scientists developed the model as a way of tracking the movement of sand and oil found along the Gulf of Mexico since the Deepwater Horizon oil spill. The new tool can help guide clean-up efforts, and be used to aid the response to future oil spills.
Following the Deepwater Horizon spill, denser-than-water conglomerates of sand and oil have been found in the surf zone, ranging in size from less than a millimeter to mats up to a few meters in size. The surf zone is where waves break as they approach the shore. The USGS study looked at conglomerates several centimeters thick – known as "surface residual balls," or "SRBs", which continue to emerge in some beach locations more than three years after the first oil reached the shoreline.
Applying the model to movement of SRBs along the coast of Alabama and western Florida showed that normal wave conditions, less than 1.5 to 2 meters, will not move centimeter-sized SRBs alongshore. However, tropical storms, or winter storms can mobilize and redistribute these SRBs alongshore.
The numerical model indicated that inlets trap SRBs, where they could accumulate over time. The model also suggests that when larger SRBs are found they are more likely to have been formed locally when the oil came ashore, rather than being transported from a different location along the coast.
Published this week in Marine Pollution Bulletin, the report also shows that SRBs are likely to be covered and uncovered by sand that is relatively easily moved by waves and currents in the surf zone.
"SRBs are dense enough to rest on the seafloor, rather than floating. Because sand grains are smaller and more mobile than the larger SRBs, under non-storm conditions when the SRBs themselves are not moving, they can be buried and exhumed by mobilized sand," said P. Soupy Dalyander, a research oceanographer and lead author of the study.
In addition to providing guidance for the Deepwater Horizon clean-up effort, the USGS methodology has broader potential application.
"The techniques developed here can be applied to evaluate the potential alongshore movement of SRBs in other locations or from any future spill where large quantities of oil and sand mix in the surf zone", said Dalyander.
LINCROFT, N.J. -- With a new year upon us, now is an ideal time for people to review their insurance policies. Understanding the details of what specific policies cover and what the policyholder is responsible for after a disaster is important as both clients’ needs and insurance companies’ rules change.
Insurers’ decisions and legislative changes have the biggest effect on changes in policies. Consumers should make themselves aware of possible changes in these areas and know what to look for while reviewing their policies.
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SPRINGFIELD, IL – FEMA and the U.S. Small Business Administration report federal disaster assistance to Illinois tornado survivors affected by the November storms has surpassed $21 million.Language English
FEMA Awards $441,750 Grant to City of Chicago: Hazard Mitigation funds will be used to make flood retrofits to River City Condominium
CHICAGO – The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) has released $441,750 in Hazard Mitigation Grant Program (HMGP) funds to the City of Chicago, Ill., for the proposed structural retrofits to the River City Condominium building. The project includes the elevation of an existing marina wall and the installation of a sewer backflow preventer. <?xml:namespace prefix = o />Language English
The Federal Emergency Management Agency (FEMA) today released Preliminary Flood Insurance Rate Maps (FIRMs) for Middlesex and Monmouth Counties that reflect the latest refinements to the ongoing analysis of flood hazards. This release is the next step in the coastal Flood Insurance Study update. The Preliminary FIRMs replace the Preliminary Work Maps for Middlesex and Monmouth Counties that were released in June/July of 2013 as an interim product.Language English
Donita Turk ( Phone: 785-832-3570 );
Evaluations of water nutrient ratios suggest that concentrations of a class of cyanobacteria toxins (cyanotoxins), called microcystins, tended to decrease as the total nitrogen to total phosphorus (TN:TP) ratio increased.
Nitrogen addition and phosphorus removal treatments were used to control nutrient ratios in confined experimental chambers in Willow Creek Reservoir, Ore., over two consecutive summers.
Two scientific articles on this research, recently published in the scholarly journal Lake and Reservoir Management, were completed as a joint partnership between the University of Idaho and the U.S. Geological Survey. The study supports previous work done on nutrient ratios and microcystins. The articles, entitled "Experimental manipulation of TN:TP ratios suppress cyanobacterial biovolume and microcystin concentration in large-scale in situ mesocosms," and "Experimental additions of aluminum sulfate and ammonium nitrate to in situ mesocosms to reduce cyanobacterial biovolume and microcystin concentration," are available online.
"This does not necessarily mean that increasing nitrogen in a lake will decrease cyanotoxins," said USGS scientist Ted Harris. "This was a study done in one location, and warrants further research."
This case study suggested that a TN:TP ratio of 75:1 or larger resulted in the growth of green algae instead of toxic cyanobacteria. Toxic cyanobacteria can produce toxins such as microcystins which can be harmful to aquatic life, terrestrial animals, and humans. Cyanotoxin exposure has led to illness in wildlife, livestock, and humans and can result in death in severe exposure cases.
Results from this research could help manage cyanobacteria toxin production; however these approaches need to be studied more extensively in whole-lake settings to fully understand the implications of using these approaches to control cyanobacteria toxin production balanced against other potential environmental harm and socio-economic conditions.
For more information:
- USGS Kansas Algal Toxin Research Website
- USGS Nutrients National Synthesis Project
- USGS Toxic Substances Hydrology Program
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Oklahoma.
Assistance for State, Tribal, and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. – The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Oklahoma to supplement state, tribal, and local recovery efforts in the area affected by a severe winter storm during the period of December 5-6, 2013.Language English
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Vermont.
Assistance for the State and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. – The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Vermont to supplement state and local recovery efforts in the area affected by severe winter storms during the period of December 20-26, 2013.Language English