Research Cruise to the Gulf of Mexico - Bush Hill Area (GC185 Block) DAY 2: At around 8 am this morning, the Roger Revelle has officially set sail! With this event, the science team and crew have been hard at work in preparing and maintaining the instruments needed for this expedition. Quite a bit of training and presentations were given today, ensuring that the science team had complete understanding of the overall function and mechanics of two important devices: The Jason (right and middle) and the conductivity-temperature-depth (CTD) profiling device (left, courtesy of Lucas Eytchison). The Jason is a marvel of a device, using a remote-controlled system to have direct visual and sampling access to the hydrocarbon seeps we hope to come across. The CTD profiler is a device used to efficiently measure the temperature, salinity and other physical and chemical characteristics as a function of depth within the water column. It is important to determine these qualities of an area of water since both the temperature and salinity (salt concentration) due to the variability of the factors in relation to the depth. Further updates will include the CTD profiling in action. Following the next couple days, the science team will continue to journey toward Bush Hill, and on the way perform CTD profiles at points of interest. These points have in part been determine by using satellite data, providing a visual on “eddies” which are currents of water rotating either in a clockwise or counterclockwise fashion. If clockwise, the eddy will create a vertical downwelling occurrence, which increases the sea surface in that area. If counterclockwise, the eddy creates a vertical upwelling occurrs, which decreases the sea surface height. This can clearly be seen with the warmer colors displaying higher surfaces with current arrows showing clockwise rotation, and cooler colors displaying lower surfaces and current arrows flowing counterclockwise. The photo on the left displays a visual of yesterday’s eddies along with the expedition route, and the photo on the right displays today’s eddy update. DAY 1: As many know, the Earth’s ocean is majorly a mystery. When one thinks about this concept, its common for the mind to think of the unknown or misunderstood flora and fauna within these waters, the chemistry of metabolic byproducts, or the topography of the deepest ocean floors. However, one major concept of the ocean has proven time and time again to be a incredibly important piece of the puzzle during the journey of it’s exploration: Physics. Daniela Di Iorio, our Chief Scientist, has meticulously created a research expedition to determine the physics of a particularly interesting habitat on the ocean floor, where benthic (very deep) areas contain marine hydrocarbon plumes (also known as seeps). Shown above is the route from the port in Tampa, Florida to the area in the Gulf that contains some of these points of interest. These “cracks” remove the separation between the ocean waters and natural reservoirs of hydrocarbons (oil and gas), and seep out into the surrounding waters similar to the mechanics of a groundwater spring on land. These chemicals and gases are toxic, but some (fascinating) microbial communities have adapted to be able to live within them and even “eat” the hydrocarbons as part of their metabolic diet. We hope to engage in finding these plumes and measuring their physcial properties and behaviours to further understand them as a vertical transport mechanism. Shown above is our ship, the Roger Revelle, an oceanographic research ship built in 1995 and named after Roger R. D. Revelle, a professor and researcher who’s extensive oceanographic research and findings helped shed light into the effects of carbon dioxide emissions to climate change in the 20th century. The Revelle is a massive boat, with an incredibly intricate organization of rooms and decks within it. It has cruised all around the world, including Antartica, so this ship is what is known as “heavy duty”. In later entries, further informaiton about the specific meachinery and data collection devices will be blogged. OVERVIEW Our work in the GOM at the GC600 lease block in 2017 was successful. From that we have formulated new questions, methods and procedures that we will employ in the GC185 block near Bush Hill with a new NSF grant. Bush Hill is the northernmost mound on the 184-185 block boundary. The ridge system starting at Bush Hill is around 8km in length, and likely has many naturally occurring hydrocarbon seeps along its length. Below is an example of our intended deployment scheme. We will have ADCPs that cover the entire water column (~700m), from surface to bottom. Cameras and other novel video imaging techniques will be employed to assess the visual changes in the seep site, and to get a measure of the turbulence related to the rising of a methane or oil bubbles. We will utilize Sentinel-1 SAR imagery to isolate oil slicks (using deep learning methods) within the region above our study area. We will estimate the vertical velocity of the buoyant hydrocarbon seep of interest with 2 methods, acoustically and optically. Other projects focus on the physical oceanography and meteorology of coastal Georgia as part of the GCE-LTER network, and hydrothermal vents near the Juan de Fuca Ridge as part of Ocean Networks Canada and naturally occurring hydrocarbon seeps in the Gulf of Mexico. 1) Coastal Georgia: This project has been part of the Georgia Coastal Ecosystems Long Term Ecological Research Network (GCE-LTER) (see our link on GCE-LTER: https://gce-lter.marsci.uga.edu/public/app/personnel_bios.asp?id=ddiiorio) through the National Science Foundation since 2000. Much of the data collection began in 2001 and continues to the present day. This includes sea level, meteorological, and hydrographic data at various locations in the GCE domain. Most of this data is currently available for download (at: https://gce-lter.marsci.uga.edu/), while some data is still in the processing stages. Our team is also focused on modeling the physical parameters of the Duplin River (near Sapelo Island, GA) to understand the exchange between ocean and estuary; this model is forced by observed data collected under the GCE-LTER project. 2) Juan de Fuca Ridge: Our group is part of the Ocean Networks Canada, previously known as NEPTUNE Canada (see: http://www.oceannetworks.ca/). For this project, a cabled ocean reciprocal acoustic scintillation (CORAS) system has been developed in partnership with ASL Environmental Sciences and Ocean Networks Canada and will be connected to the seafloor at the M Endeavour vent Field offshore of the southern region of Vancouver Island, BC. The primary advantage of reciprocal transmission is the ability to resolve both the mean and turbulent horizontal advective flows and temperature. Using scintillation techniques the vertical flow of the hydrothermal plume will also be monitored leading to approximations of the heat flow. These acoustic measurements are essential for developing accurate and realistic 3-D models of hydrothermal vent plumes and their interaction with the ambient ocean. Recent Completed Projects: 1) Gulf of Mexico - MegaPlume Area (GC600 Block): Our group is part of the Gulf of Mexico Research Initiative (GoMRI). “The ultimate goal of the GoMRI will be to improve society’s ability to understand, respond to and mitigate the impacts of petroleum pollution and related stressors of the marine and coastal ecosystems, with an emphasis on conditions found in the Gulf of Mexico.” (see our groups link on GoMRI: http://research.gulfresearchinitiative.org/research-awards/projects/?pid=270) See Daniela on youtube talking about our work in GOM: (https://www.youtube.com/watch?v=OJv9j78Esuo&feature=youtu.be)
