Research Cruise to the Gulf of Mexico - Bush Hill Area (GC185 Block) May 18 to 27, 2024 A day to day update by Sarah Kirk DAYS 9 and 10: As the trip ends, today marked the day of the last ROV Jason deployment (leftmost top and bottom photos, courtesy of Lucas Eytchison). The Jason began this journey at around 10 am and did not resurface until 5 am the next day, so many tasks were completed! To start off, Mahdi’s group used the ship’s elevator (seen above water in top middle photos) to carry their EP Oceanographic LLC M4500 HD cameras to the sea floor early this morning. Once the Jason found the elevator (bottom middle photo), the Jason team worked with Mahdi’s group to place the cameras at the right location near a seep (right top and middle photos) to document its activity in 4k 60 fps video. Binbin’s group reconfigured their PIV system to be a lander (bottom right photo) for its placement on the sea floor, allowing it to continue capturing the bubbles’ and the surrounding fluid motion from a chosen seep we found. Throughout the deployment, Daniela gathered many bubbles erupting from seeps using her gas flux funnel (left photos), and it was truly interesting to see how the oil and methane accumulated at the top of the funnel. Once this was complete, Daniela began her search to find her bottom lander, which was deployed on the seafloor the day before. However, after it had sunk to the bottom, it had accumulated a layer of sand and dirt and the transducers needed to be cleaned. So, the Jason used the white backdrop that had been used for Binbin’s shadow imaging to “fan off” the bottom lander (top middle photo). The Jason and science teams erupted into laughter, as it looked like a Southern Belle was feeling a bit faint and needed some air. Once the bottom lander was nice and clean again, we directed our attention to moving the ASFM moorings to the correct location (the rightmost photos show the top, middle, and bottom segments of the receiver mooring). This took some time, but in the end, they were in the right position, and you could even see the acoustic signals erupt from the transmitter array on the BlueView sonar. All the equipment placed on the seafloor will remain at Bush Hill for the next six months, constantly collecting data to be analyzed this coming November. Also, many critters were seen throughout this deployment, such as the giant isopod in the bottom middle photo! The science team, Jason team, Sentry team, and ship’s crew did such an excellent job to make all of this happen! The next day, the very final mooring was deployed! Daniela’s 300 kHz ADCP (right photo, white arrow and its parts shown in bottom middle photo, courtesy of Lucas Eytchison) and a 75 kHz (right photo, red arrow) Long Ranger ADCP attached to the giant orange buoy (top photos) with seven microCAT CTD instruments attached every 50-100 meters (one microCAT seen in bottom left photo) along the 485 m mooring line. Then a train wheel was attached as its anchor (bottom rightmost photo). These ADCPs and CTDs will take high resolution data of the full water column such as water velocity, temperature, salinity and pressure over a six-month period. On a personal note, as we head back home, I wanted to give a brief message to anyone who seeks adventure but is unsure of their capabilities. Do it! Engage in the experiences you are unsure of. Find people that help you find yourself and help them do the same. Going on this adventure has been the experience of a lifetime, where I have learned so many things and met so many amazing people. From learning about physical oceanography, to learning how to tie a bowline boating knot, and even how to pilot and control the ROV Jason (left photo). I implore you, dear reader, to take any chance like this and make the most out of it. You are truly amazing. Thank you to the ship’s crew, the Jason team, the Sentry team, Binbin’s team, Mahdi’s team, and Daniela’s team. And specifically, to Daniela and Don, for helping me see my worth. I am so proud of all of you and your achievements before, during, and after this cruise. Thank you! DAYS 5-8: After an unexpected occurrence, the Roger Revelle had to change its course to Gulf Port to pick up a needed part for a repair on the ROV Jason (top left and bottom middle photo). Once the part was obtained, the entire Jason team put their all into fixing the vehicle, and they succeeded! Because of this accomplishment and the successful deployment of the Sentry, it was time for the Remotely Operated Vehicle (ROV) Jason to steal the show! This vehicle is incredible in its own right; it’s got high-definition and ultra-high-definition cameras to capture real-time footage of the sea floor, robotic arms (shown top middle photo) powered by hydraulics that can carry up to 300 lbs, and several data collection systems to give an extensively detailed perspective on exploring inner space. At around 8 pm, the Jason was being gently lowered into the waters (top middle and right photos, courtesy of Lucas Eytchison). As it descended, the Jason team attached several football shaped buoys to the Jason’s electrical cord (bottom leftmost photo, courtesy of Lucas Eytchison), which assists in keeping the Jason’s electrical cable buoyant and at a safe placement in relation to both the Jason and the ship. On the boat is the Jason mission control van (bottom rightmost photo), which contains the navigation systems and monitors providing a flawless view of the Jason’s point of view in all angles as it explores the sea floor. Several members of the science team worked through the night surveying the observations made by the Jason, paying special attention to the sight of any suspicious looking bubbles rising from the sea floor. More info on Jason: https://ndsf.whoi.edu/jason/ After about an hour of the Jason exploring the seafloor, the first plume was finally seen! (seen in top leftmost photo and bottom rightmost photo). Gasps of relief and joy were heard throughout the van as the ultra-high-definition cameras focused on the little, tiny bubbles escaping from the ocean floor. Some bubbles were completely clear, while others were entirely brown. The normal bubbles quickly rose to the surface, becoming smaller and smaller as the methane gases within them diffused into the surrounding waters. The brown bubbles, however, retained their shape and color, as these are the bubbles which are coated in oil and do not let the methane gas diffuse out until they arrive at the ocean surface. Several other plumes were found and analyzed throughout Bush Hill, and many critters simply passing by were seen and gawked over by the people in the van. Sharks, starfish, shrimp, several types of crustaceans, squid, eels, and a plethora of fish were seen swimming by and looking rather surprised by our appearance in their home. Binbin’s group ran some very interesting measurements on the bubbles using their Particle Imaging Velocimetry (PIV) system (top right photo), which consists of a camera (white arrow) and a laser (purple arrow). The camera is used to capture pictures of the bubbles which, as they are illuminated by the laser (seen flashing in the bottom left photo), provide measurements of the bubble movement for turbulence and velocity calculations. The camera is also used during a shadow imaging technique which utilizes a white backdrop (top left and bottom right photos) to capture images of the bubbles’ shadows which provides an understanding of the size distributions of the bubbles. Now that we have accumulated the extensive data of the Bush Hill seep locations and characteristics, it is time for the deployment of the oceanographic sensor measurements! Daniela’s bottom lander was deployed (top and bottom left most photos), which contains a 5-beam Acoustic Doppler Current Profiler (ADCP). This profiler determines the velocity of surrounding water currents using acoustic data for the purpose of understanding how the bubbles are carried away from their seep source via currents. This bottom lander will live at the bottom of the ocean collecting the velocimetry data of the currents next to the seeps. The Acoustic Scintillation Flow Meter (ASFM) consisting of two moorings (a transmitter array and a receiver array) were deployed (left middle and bottom rightmost photos, courtesy of Lucas Eytchison), which measures the vertical flow of the bubbles emerging from the seeps using acoustical scintillation analyses. One mooring transmits an acoustic pulse through the bubble plume, while the other receives it. The ASFM uses an anchor to hold them in place (middle right photo) and a buoy (top rightmost photo) to hold the ASFM vertical, keeping the system stable. In an interesting note, Lucas and I were peering into the waters as the Jason deployment took place, and saw fascinating oil covered bubbles rise to the surface, pop, and dispel a glob of oil. The photo above displays how the oil escapes the hydrocarbon seep bubbles creating a surface oil slick and adding methane to the atmosphere. DAY 4: Huzzah! We arrived at Bush Hill (bottom left photo), and our first plume has made an appearance, and the entire science team couldn’t be more excited to explore them! They were found using a device known as a multibeam sonar attached to the bottom of the ship, which is an acoustic array with 512 beams insonifying the water column and seafloor. Back in the computer lab, the team had been looking at the multibeam images, and saw a tall, long signal in the middle of the display, which is the bubbles rising from a searfloor seep! The Bush Hill site was even clearly seen using Chirp Sonar technology which uses sound waves to penetrate and scatter throughout the sea floor and sends back the data as it is seen in the bottom right photo. Now that the plumes have been found, further investigations and data collections can occur! Three cheers for this discovery! As the ship continued to survey the possible plumes around Bush Hill, the data was also seen on a 18kHz Fisheries echosounder. This device is usually used to locate schools of fish by detecting the presence of their swim bladder, which is an internal gas-filled organ used by fish to control their buoyancy. It also detects zooplankton which, interestingly, shows their diel vertical migration, which is when masses of zooplankton migrate from the ocean surface at night to deeper waters during the daytime (left photo) for safety. In relation to the plumes, the sonar device detects the bubbles released and displays a green peak for each plume identified. A very large plume can be seen on the very right of the rightmost picture. While exploring the ship, Charles and Josh (middle photo, courtesy of Lucas Eytchison) saw what appeared to be an oil slick floating in the distance. This slick (left photo) is especially interesting because it could be where the bubbles of gas and oil exiting from the seafloor are being carried up to the surface and displaced by currents and gas is then emitted into the atmosphere. In addition to this sighting, Daniela received synthetic aperture radar data from satellite observations displaying a bird’s eye view of the oil slicks! (right photo) These oil slicks occur because of oil seepage and oil covered gas bubbles prevents the methane from diffusing into the water as it would normally. Then, the bubbles carry the methane up to the sea surface, where the bubbles finally release the methane into the air. As many know, methane is a greenhouse gas, so this emission of methane is a contributor to global warming. It has truly been an exciting day for the science team! Along with all our discoveries, the Autonomous Underwater Vehicle (AUV) Sentry was deployed! This deep-sea submersible can dive to 6,000 meters and provide detailed maps and visuals of the ocean floor, take photos of the terrain, and measure ocean properties, in a sort of scanning pattern similar to mowing the lawn. The bottom two photos were taken while the Sentry explored Bush Hill, and many interesting critters were seen lurking in the deep dark, such as a squid (bottom left photo) and a giant isopod around some tube worms (bottom right photo). The Sentry team (from left to right) Isaac, Mike, Justin, Sean, and Norman feel very good about the successful deployment! Now that we have a better perspective on Bush Hill, the science team can continue preparing for the exciting deployment of the ROV Jason, which will be covered in a future update! More Sentry info: https://www.whoi.edu/what-we-do/explore/underwater-vehicles/auvs/sentry/ “The ocean is the last great frontier” – Brent Devries DAY3: As people get acquainted with each other, our science team led by chief scientist Daniela Di iorio, found some opportunities for a photo op! Dr. Binbin Wang’s group (UM, left most photo) is comprised of Xuchen Ying (left), Dr. Binbin Wang (right, crouched), and Mustahsin Reasad (right, standing). Their group is focused on utilizing an underwater particle imaging velocimetry device (shown in the bottom middle of the photo) on board the Remotely Operated Vehicle (ROV) Jason to take images and view the flow characteristics within the hydrocarbon seep/plume. Dr. Mahdi Razaz’s group (middle photo) is comprised of Dr. Mahdi Razaz (USM, left), Joshua Seymour (middle), and Charles Heatherly (right) and their main focus is using very high-quality cameras (shown in the photo) deployed next to the seeps to capture their activity by using particle tracking over a 6-month period. Dr. Daniela Di Iorio’s group is comprised of Sarah Kirk (the science blogger, left), Lucas Eytchison (middle left), Dr. Daniela Di Iorio (middle right), Grace Waters (not shown) and Donald Newman (right). Our group is focused on determining the effects of the oceanographic environment on the behavior of seeps themselves by monitoring the vertical transport associated with the bubble plume and the ocean movements. Two different acoustic current meters are utilized, one which measures the surrounding water currents in various directions using acoustics, and the other measuring the motion and flow of the plumes themselves all deployed on moorings or bottom landers. As we all get a feel for the instrumentation used during this cruise, Daniela assisted in helping her team understand what does what in the computer lab. Specifics like CTD profiler data, sonar data, and more were shown in relation to the ship’s location and current measurements. It is very important to pay attention to these monitors, as calibrations and measurements can go awry and must be in tip top shape for the upcoming deployment days. The conductivity, temperature and depth (CTD) profiler put in its fair share of work today! Throughout the night, 7 CTD profiles were done, allowing the science team to get a thorough understanding of the waters as we approach Bush Hill. The profiler will collect conductivity and temperature data at different water depths, allowing for the salinity and density of the water to be calculated as a function of depth. This together with the physical currents will allow us to understood the physical processes in the area. The left and middle photos display the CTD being prepared for deployment, and the two right photos show it in action, as it was lifted and placed into the water. The profiler is then brought up and down throughout the water column, and the grey Niskin bottles can be used to collect samples of water at different depths. Once brought back up, the CTD profiler has obtained its data, and Daniela and Grace in the computer lab prepare for the next profile. The graph at the bottom right displays when each CTD profile was taken as a dip in the green line. More CTD info: https://oceanexplorer.noaa.gov/facts/ctd.html Also, the evening sunset was particularly beautiful so I wanted to share! Thanks for reading, check back soon! DAY 2: At around 8 am this morning, the RV Roger Revelle has officially set sail! With this event, the science team and crew have been hard at work in preparing, maintaining and securing 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 remotely operated vehicle (ROV) Jason (left and middle) and the conductivity-temperature-depth (CTD) profiling device (right, 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 planned locations for CTD profiles through the small eddy, 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. The seafloor is the separation between the ocean waters and natural reservoirs of hydrocarbons (oil and gas) beneath, and gases and oil 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 physical properties and behaviors to further understand them as a vertical transport mechanism. Shown above is our ship, the research vessel (RV) Roger Revelle, an ocean class 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 RV Revelle is a massive boat, with an incredibly intricate organization of rooms and decks within it. It has cruised all around the world, including Antarctica, so this ship is what is known as “heavy duty”. In later entries, further information about the specific instrumentation 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)
