Posts Tagged ‘geology’

UGA Skidaway Institute researchers study sand resources near the Georgia coast

January 7, 2016

If a hurricane hits the Georgia coast, a major priority for coastal communities will be finding sand to rebuild beaches destroyed by erosion. University of Georgia Skidaway Institute of Oceanography scientist Clark Alexander has received funding approval from Georgia Sea Grant for a two-year study to collect and analyze new, high-resolution data to identify the sand resources available near the Georgia coast.

In 2012, Hurricane Sandy caused billions of dollars in damages to communities along the east coast of the U.S. Coastal communities in Georgia are vulnerable to future storms, and some have begun to develop strategies to increase their resilience to such storms and to speed their recovery from one. When it comes to restoring storm-eroded beaches, those communities will require a detailed understanding of the locations and characteristics of the available sand resources they will need.

Beaches like Glory Beach on Jekyll Island may potentially benefit from the sand resource study.  Photo Credit: www.GoldenIsles.com

Beaches like Glory Beach on Jekyll Island may potentially benefit from the sand resource study.
Photo Credit: http://www.GoldenIsles.com

“Sand resources are needed to rebuild beach and dune systems to provide the same or better levels of protection to lives and property,” Alexander said. “These sand resources data are critically needed in Georgia, as the sand resources in our state waters are the most poorly known of all the states along the East Coast.”

The study will focus on three developed barrier islands that have not been renourished — Sea Island, St. Simons Island and Jekyll Island. The project will gather new samples and data on seabed sediment texture and composition from the beach out to the state-waters boundary, three nautical miles offshore. The researchers will merge that data with existing samples from the beaches and the sea bed and integrate all the samples to determine where sand deposits are located that would be suitable for beach renourishment.

“Typically, we find a wide range of sand, and not all of it is beach-quality,” Alexander said. “We need to locate sand deposits that have similar size and composition to the natural beach.”

The team will collect beach grain size samples during both the summer and winter to assess the differences in texture and composition in the beach in response to changing storm, tide and wave conditions.

The sea floor in the study region has not been comprehensively surveyed since the 1930s. Another part of the project will be to use an echosounder to collect data on the depth and morphology of the sea bed. This data will be used to create bathymetric maps of the ocean bottom. These maps will also identify regions of thicker sand deposits, which indicate greater volumes of sand.

The researchers will then combine the new information with existing data in a Geographic Information System tool to integrate the sand resource and bathymetry information and model the extent of beach-quality deposits in the Sea Island to Jekyll Island region.

The results of the project will be made available online to government officials, the management community and the general public on a number of Web sites, including the Georgia Coastal Hazards Portal (http://gchp.skio.usg.edu/) developed by Alexander.

Georgia Sea Grant is a unit of the UGA Office of Public Service and Outreach.

Skidaway Institute scientist shares Gulf oil spill research grant

December 17, 2014

University of Georgia Skidaway Institute of Oceanography scientist Catherine Edwards is part of a research team that has received an $18.8 million grant to continue studies of natural oil seeps and track the impacts of the BP/Deepwater Horizon oil spill in the Gulf of Mexico ecosystem.

Known as ECOGIG-2 or “Ecosystem Impacts of Oil and Gas Inputs to the Gulf,” the project is a collaborative, multi-institutional effort involving biological, chemical, geological and chemical oceanographers led by the University of Georgia’s Samantha Joye. The research team has worked in the Gulf since the weeks following the 2010 Macondo well blowout.

The three-year, $18.8 million ECOGIG-2 program was funded by the Gulf of Mexico Research Initiative, or GoMRI.

“Our goal is to better understand the processes that have affected the oil spill since 2010,” Edwards said. “How the droplets were dispersed? Where the oil went? How it was taken up by small microbes and also the effects on animals further up the food chain?”

Skidaway Institute scientist Catherine Edwards adjusts a glider’s buoyancy with graduate students Sungjin Cho and Dongsik Chan.

Skidaway Institute scientist Catherine Edwards adjusts a glider’s buoyancy with graduate students Sungjin Cho and Dongsik Chan.

Edwards’ role in the project is to use autonomous underwater vehicles, also called “gliders,” to collect data on conditions around the spill site. Equipped with sensors to measure characteristics such as depth, water temperature, salinity and density, the gliders can cruise the submarine environment for weeks at a time, collecting data and transmitting it back to a ship or a shore station.

“We want to understand the ocean currents—how they change over time and how they change in depth,” Edwards said. “Surface measurements give us a two-dimensional picture of the ocean. Glider data in the vertical provides more valuable information for more fully understanding ocean currents and how they arise.”

The gliders will operate both in conjunction with shipboard instruments and also independently. One advantage of using the gliders is they can operate during storms and rough weather, when it may not be possible to use ships. Edwards said shipboard work doesn’t always give a full picture of ocean dynamics simply by the fact that they can only go out when the weather is reasonably clear.

When working in conjunction with research ships, the gliders can provide additional observations, significantly improving the quality of the data set. The gliders also report dissolved oxygen concentrations and optical measurements of chlorophyll and organic matter, and may also be used as a test vehicle for new instruments in development.

Edwards will use “GENIoS,” a new software package, to help navigate the gliders. GENIoS uses high-resolution forecast models of wind and ocean currents, along with information from the glider itself, to calculate the optimal path for the gliders. This will improve the quality of the scientific data collected.

GENIoS is a collaboration among Edwards, Fumin Zhang from the Georgia Institute of Technology and their two Georgia Tech Ph.D. students, Dongsik Chang and Sungjin Cho. GENIos has been tested for more than 210 glider-days on the continental shelf off Georgia and South Carolina. This experiment will be its first test in the Gulf of Mexico.

Edwards also hopes to use this project to test the gliders as platforms for new, experimental sensors developed by other members of the ECOGIG-2 team.

Others involved in ECOGIG-2 include UGA marine sciences faculty Christof Meile, Renato Castelao and Catherine Edwards as well as Annalisa Bracco and Joe Montoya of Georgia Tech.

For additional information, contact Catherine Edwards at (912) 598-2471 or catherine.edwards@skio.uga.edu.

UGA Skidaway Institute to study offshore sand resources to increase coastal resiliency

August 11, 2014

Severe beach erosion can be a significant problem for coastal communities affected by hurricanes and tropical storms like Hurricane Sandy. To assist Georgia communities in future recovery efforts, the University of Georgia Skidaway Institute of Oceanography entered into a cooperative agreement with the Bureau of Ocean Energy Management to evaluate existing data on Georgia’s offshore sand resources and identify where more data are needed. This consolidated information will increase knowledge of Georgia’s offshore sand resources and contribute to long-term coastal resilience planning.

“Georgia’s sand resources are arguably the least well-known of those along the East Coast, and this project will provide critical data and insights to enhance coastal resilience,” said UGA Skidaway Institute professor Clark Alexander. “The work is being coordinated closely with the Georgia Department of Natural Resources and the state geologist to assure that our findings are disseminated rapidly and broadly.”

Beach communities like Tybee Island  can be affected by hurricanes and tropical storms.

Beach communities like Tybee Island can be affected by hurricanes and tropical storms.

Under the $200,000 agreement, UGA Skidaway Institute will gather, evaluate and analyze existing geological, geophysical and benthic habitat data off Georgia’s coast and identify gaps in the information. Based on the data gaps, project scientists will suggest areas for future geologic studies to confirm previously identified sand resources and locate new ones.

“A reliable inventory of offshore sand resources will help the Department of Natural Resources be effective at representing the state’s interest in discussions with BOEM and other federal agencies. We appreciate the initiative of Dr. Alexander and the UGA Skidaway Institute and look forward to the results of this project,” explained Spud Woodward, director of the Georgia DNR Coastal Resources Division.

The current project will be limited in scope – primarily evaluating and consolidating existing data regarding Georgia’s offshore resources.

“Since the 1960s, there have been quite a number of small studies, but the information is scattered,” Alexander said. “This project contributes significantly toward the goal of more fully understanding available sand resources by synthesizing existing information into a single, digital resource.”

Much of the older information is only available in printed form, and needs to be converted to a digital format to be useful in the software that managers and scientists use for viewing and analyzing data. The goal of the project is to have all the compiled information readily accessible to coastal managers and municipal planners.

“This agreement demonstrates BOEM’s commitment to work with Georgia to help coastal communities recover from the effects of Hurricane Sandy and enhance resilience efforts for the future,” said BOEM Acting Director Walter Cruickshank. “We are committed to continuing to work in a collaborative manner to help local communities withstand damage from future storms.”

This agreement is one in a series of partnerships with 14 coastal Atlantic states, using part of the $13.6 million allocated to BOEM through the Disaster Relief Appropriations Act of 2013. The combined agreements support research that will help to identify sand and gravel resources appropriate for coastal protection and restoration along the entire Atlantic Outer Continental Shelf.

Skidaway Institute scientists seek answers to salt marsh questions

January 2, 2013

Salt marshes are a vital part of the coastal ecosystem. They provide a nursery for many kinds of marine animal life. Sitting in the transition zone between the ocean and the land, salt marshes serve as a physical buffer against severe weather. They act as a chemical buffer by capturing, holding and releasing nutrients that are brought in on each tide. As a result, the marshes have a great influence on the type and amount of nutrients that enter the sounds and the ocean. That buffering capacity varies on tidal, daily and seasonal time scales, but how it functions is poorly documented.

A team of Skidaway Institute of Oceanography scientists have begun a project to get a clearer picture of how salt marshes function and interact with their surrounding environment.

The composition of the science team reflects the interdisciplinary nature of the project. Principal investigator Jay Brandes, Aron Stubbins and Bill Savidge are chemical oceanographers, and Catherine Edwards is a physical oceanographer. Geologist Clark Alexander and physical oceanographers Jack Blanton and Dana Savidge are also contributing to the effort. The three-year project is funded by a $699, 971 grant from the National Science Foundation.

The research team at Groves Creek (l-r) Clark Alexander, Jack Blanton, Catherine Edwards, Jay Brandes, Dana Savidge, Bill Savidge, Aron Stubbins

The research team at Groves Creek (l-r) Clark Alexander, Jack Blanton, Catherine Edwards, Jay Brandes, Dana Savidge, Bill Savidge, Aron Stubbins

“Scientists have looked at salt marshes in the past and have gotten some good data,” Brandes said. “However, this will be the first detailed look at the combined functions of one of these marsh systems.”

The project will focus on Groves Creek, a portion of coastal salt marsh along the Wilmington River, adjacent to the Skidaway Institute campus. Groves Creek has been the site of other research projects.  Over the past three years, Blanton, Alexander, Dana Savidge and others have studied the topography and water-flow in the marsh as part of a Department of Energy-funded project.  Because of this, the physical layout of the marsh has been documented to a fine detail.

“We already know a lot about this area, especially how the water moves in and out of the marsh on the tides,” said Brandes. “We have a very good understanding of the topography of the top of the marsh and its tidal creeks, both above and below the surface.”

The scientists also believe the Groves Creek area is fairly representative of salt marshes along the Georgia and South Carolina coasts.

From a chemical standpoint, the research will focus on way the salt marsh uses carbon: is it a consumer or producer of carbon-based organic material and nutrients?

“Marshes take material in from the river on every high tide, and they deliver material back to the river on the falling tide — but it isn’t the same stuff,” Savidge said. “The marsh changes the river chemistry on every tidal cycle.”

There isn’t much consensus on what controls that exchange between river and marsh. “That is one of the big questions,” said Brandes, “Trying to understand whether the marsh is a producer or consumer, and how that changes over time, the seasons, the tides and so on.”

To get a detailed history of marsh-river exchange, the scientists will place sensors in the marsh that will measure various conditions every 15 minutes. Remote sensors cannot measure everything, so the research team will also be collecting samples on a daily basis and returning them to their labs for analysis.  Understanding the big picture will come from adding up all the little incremental changes over time and relating them to the actions of sun, tide and weather on the marsh surface.

Stubbins will focus his efforts on the role of dissolved organic carbon in the marsh. Savidge will work look at how the salt marsh uses dissolved oxygen. Edwards will be modeling how water flows in and out of the system and how that movement interacts with the chemical and biological activity.

When the project is complete in three years, the Skidaway scientists expect to have a much more extensive picture of the role salt marshes play in the larger coastal ecosystem.

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A great day-trip to Ossawbaw Island

March 4, 2011

A team of Skidaway Institute scientists visited Ossawbaw Island this week.

The beach

One of the main reasons for the trip was to perform some maintenance on the Barrier Island Network.

Skidaway Institute is one of a group of organizations developing a network of cameras and sensors that will turn the island into a remote laboratory for researchers and students. Right now the network consists of a weather station, a water monitoring sensor at the main dock, two more in wells in the interior of the island and a camera at the dock. You can access the pictures and data here.

(l-r) Herb Windom, Bob Antonelli, Charles Robertson, Sam Cook and Debbie Wells examine a a sensor that spent a little too much time in salt water.

The technical crew needed to change out the sensor at the dock and install a sensor in one of the wells. Long-term exposure to salt water is very rough on scientific equipment.

We got around mostly in pick-up trucks.

Also, the geology team of Clark Alexander and Mike Robinson tramped through the woods to find a good site to obtain core samples.

Clark Alexander and Mike Robinson emptying a core.

That is part of a project to date the origin of the island.

Kathryn Sutton at the beach with her air sampling gear.

Georgia Southern grad student Kathryn Sutton also went along to obtain air samples from the beach and to collect Spanish moss for her research project looking at the possibility of using Spanish moss as a bio-indicator of atmospheric mercury from coal-fired power plants.

The team also placed a new sensor in one of the two research wells on the island.

Sam Cook (Siemitsu Computers) and Bob Antonelli hook up the well sensor while Charles Robertson looks on.

We didn’t see a lot of wildlife this time around. The fresh water ponds are low, which probably keeps the alligators away from the various causeways. Herb Windom and Paul Pressly (Ossabaw Foundation) did meet one of the island’s pet pigs, “Paul Mitchell.”

Heb Windom and Paul Pressly meet "Paul Mitchell."

It was a beautiful day and the island scenes were, as always, a treat.

A dead tree on the Ossabaw beach

Dead palm trees

An Ossabaw Island saltmarsh

That’s a lot of mud!

October 8, 2008

One of our scientists, Clark Alexander, just returned from two weeks in China, where he attended the 7th International Conference in Tidal Sedimentation in Qingdao, China.

 A Chinese coastal vessel is intentionally grounded at low tide so the crew can search the mud for shellfish. Come high tide, it floats again.

A Chinese coastal vessel is intentionally grounded at low tide so the crew can search the mud for shellfish. Come high tide, it floats again.

Prior to the meeting, he took part in a 5-day field trip which covered 1,500 kilometers along the west coast of the Yellow Sea, from Shanghai to Qingdao, where he was excited to observe one of the best tidal bores and some of the muddiest and most extensive tidal flats in the world.

Alexander is a member of the International Scientific Steering Committee for this quadrennial series of meetings, and he gave a keynote presentation on the hammock stratigraphic work being carried out by his lab group.