Antarctic Moorings

I am McKensie Daugherty, your host for on the ocean. Scientists at Texas A&M University are researching the heat transfer into East Antarctica by ocean currents. With thirty nine percent of the U.S. population living by the coast, it is important to understand how much heat is melting the ice caps to get estimates of sea level rise. Relatively “warm” water is coming from the deep ocean into Antarctica. The ice shelves are a couple hundred meters thick and floating on the ocean, and seawater fills underneath in cavities that can reach the ground of the Antarctic ice sheet. To get the temperature and other measurements of the ocean by the floating ice shelves, scientists place moorings which have sensors at different depths. Placing moorings near the ice shelves poses many challenges for scientists. Often times when going to collect the moorings, the equipment will actually have ended up underneath the ice shelf. To get the moorings out, the scientists have to drill for hours through thick ice. From the data the moorings collect, scientists are able to calculate the heat flow at different depths. Recently, researchers have noticed relatively “warm” waters at a depth of one thousand meters coming in under the ice shelfs. These waters are estimated to cause more melting than any other measurement reported before in this area of Antarctica. Climate change may only adjust the overall temperature of the ocean by a fraction, but it could have a large impact on Antarctica’s ice melting rate.  This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Script Author: Ty Wilson

Contributing Professor: Dr. Alejandro Orsi

Sea Turtles and Coastal Erosion

Sea turtles and coastal erosion

 

I’m McKensie daugherty, your host for On The Ocean. Sea Turtle nesting season is in full swing, and most people are not aware of the key components needed to have a safe and successful nesting. Five of the seven species of sea turtles nest in the Upper Texas Coast along Galveston Island, Follets Island, and Bolivar Peninsula. Beach development, poaching, fishing, shrimping, and other natural predators have caused a significant decline in the population of sea turtles and nestings occurring in this region. Coastal erosion along these islands has caused the General Land Office of Texas to replenish the beaches every year with average to low quality sand. These projects have had an effect on the amount of turtles nesting along newer beaches. Sea Turtles need access to beaches with high sand content, elevated dunes, and small amounts of vegetation to properly nest. The sand recently placed on Galveston and Follets Island during the renourishment project have a high clay content. This higher concentration of clay can make it difficult for sea turtles to burrow a nest,  as well as kill the developing eggs inside the nest. The Turtle Island Restoration Network and the Coastal Geology Lab of Texas A&M University in Galveston have joined together to study the quality of the sand brought in to replenish the beaches and find ways to mitigate the impacts from the beach renourishment project. This is an effort to make our coast a suitable nesting environment for sea turtles. The Restoration Network’s main focus in the Gulf of Mexico is to advocate and protect all sea turtles, hopefully keeping sea turtles nesting on our coastlines. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Script Author:Lindsay Breedlove

Contributing Professor: Dr. Timothy Dellapenna.

Special thanks and Acknowledgements to Tess Morris from the Turtle Restoration Network

More information and links:

Figures by Lindsay Breedlove

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GLO site graph shows the grain size distribution of the new “Sand” added to the beach from the project. Not showing a healthy beach.

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Galveston State Park graph shows grain size distribution from a sample taken at the Mid-dune. It shows that a healthy beach should have 100% sand

1024x1024 Beach Renourishment project on Galveston Beaches

Sea Level Rise

Sea level Rise

I’m McKensie Daugherty, your host for on the ocean. Scientists have recorded a global rise in average sea level due to an increased volume of water in our oceans. The exact rate at which sea level rises can vary at specific locations, and depends on several factors. Along the Texas coast, the trend of sea level rise has been enhanced by the sinking of the ground level due to the compaction of soft ocean sediment.  In Galveston Bay, measurements from the Pier 21 tidal gauge show that the sea level is rising at a rate that is 3 times the global average. This high rate has been considered the standard rate of sea level rise for the entire Galveston Bay region, and preparations for future flooding in the area have been made based off this high rate of sea level rise. Researchers at Texas A&M University have found that within Galveston Bay, the ground is actually sinking at drastically different rates across the bay and is sinking fastest in an area where ocean sediment is thickest. This area of thick ocean sediment sits directly below the Pier 21 tidal gauge and only covers a small portion of Galveston Bay, which leads researchers to the conclusion that sea level is not rising as quickly within all portions of the bay as previously thought. Researchers plan to continue their studies in Galveston Bay to better understand the sinking of ocean sediments and to help prepare for future sea level rise along the Texas. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click “On the Ocean”.

Script Author: Andrew Pekowski

Contributing Professor: Dr. Tim Dellapenna

Year 2 Antarctica -R/V Laurence McKinley Gould

R/V Laurence McKinley Gould

The Research Vessel Laurence McKinley Gould, or LMG for short, is the sister ship to the larger R/V Nathaniel B. Palmer. Both are United States icebreakers, or at least “ice reinforced” in the case of the LMG. This vessel is well equipped for research expeditions in Antarctic waters, but also serves as a supply ship for US stations in Antarctica. Palmer Station sits on Anvers Island, one of the first points of land when traveling south from the tip of South America, across the Southern Ocean toward the West Antarctic Peninsula. If you can survive the infamous Drake Passage, known for some of the roughest seas in the world, you are rewarded with snowy mountains, icebergs and plenty of wildlife. However, life on a ship is not all gorgeous days and whale watching. Texas A&M scientists and students from the Department of Oceanography experienced this in austral summer 2016. In their makeshift lab they often worked on collecting and filtering water for experiments around the clock. The science does not wait for anyone and when they arrived at a new station, they had to be ready at all hours of the day to collect samples, often in very cold and wet conditions. In 2016 they encountered more sea ice coverage than is typical for the summer near Antarctica, which slowed the boat down considerably. This was, of course, a major factor for limiting historical scientific settlements in Antarctica. Ice coverage blocks ship passage, and cold weather makes even flying airplanes to Antarctica nearly impossible. At some Antarctic research stations, new food and supply shipments cease in April and don’t return until October. Even on a ship, supplies are carefully planned out for length of voyage and some emergency stores in case the ship gets stuck in the ice or has to make an unplanned detour. The ice coverage was good news for the Texas A&M scientists’ sleep schedules but bad for science, as they weren’t able to collect as many significant surface ocean samples as they needed because of ice cover. Part of polar research is being prepared for the unexpected and they managed to use their sample time wisely for their experiments investigating the potential for iron limitation of microscopic photosynthetic activity. We stand to gain much in our understanding of the global carbon cycle from these types of studies in critical regions such as the great Southern Ocean. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click “On the Ocean”.

Script Author: Laramie Jensen

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Photos of Antarctica as taken from the R/V LMG