April 20, 2011, marks the one-year anniversary of the worst oil leak in U.S. history. Although the broken rig was sealed on September 19, 2010, Scripps Institution of Oceanography at UC San Diego researchers still have much to study and learn about the aftermath in this region.
ONGOING GULF RESEARCH – SCRIPPS INSTITUTION OF OCEANOGRAPHY
• Spray Glider Surveys
Scripps Institution of Oceanography, UC San Diego researchers are continuing to utilize the unique abilities of robotic gliders developed at the institution to collect data on currents in the Gulf of Mexico.
BP, which has funded previous surveys performed by the glider known as Spray, is again supporting research that will see the deployment of three gliders beginning in May 2011. The gliders will gather information on local currents in the Gulf. Because of Spray's navigational capabilities, programmers will also direct the gliders through the Loop Current, the strong flow that can transport materials in Gulf waters to the Atlantic Ocean.
Spray operators will also deploy another glider in a different Gulf region as part of a collaboration with Mexican oceanographic research center CICESE. Data from both projects will feed models at Scripps that could eventually give rise to prediction products. Those products could assist oil and gas exploration companies and other end-users in applications ranging from platform safety in high currents to surface transport.
• High Frequency Radar Networks
Scientists at the Coastal Observing Research and Development Center (CORDC) continue to enable data access through the High-Frequency (HF) radar national network to seven shore-based high-frequency (HF) radar stations in the Gulf of Mexico. The stations, three of which operated by the University of Southern Mississippi and four by the University of South Florida, deliver near-real-time surface current data. CORDC also installed one of the first platform-mounted HF radar on BP's Atlantis platform. The station has been operational since September 2010. Radial currents from this radar are made available to researchers and utilized in circulation models to improve forecasts. Initial plans are under way for deployment of a second radar on BP's Thunder Horse, another deepwater platform in the Gulf of Mexico.
CORDC is also planning to deploy an array of ocean drifters for measuring waves and currents in the Gulf of Mexico later this year. The drifters will provide data on hurricane-generated waves and will enable study of how the Loop Current influences ocean waves.
• FEATURE STORY: A more detailed look at Scripps' involvement with the oil leak appeared in the November/December issue of Scripps' e-magazine explorations, which examines the efforts that Scripps researchers made in the field including monitoring marine mammals, looking for subsurface oil plumes using programmed gliders and bringing dormant radar stations online to make near real-time maps of surface currents.
• SPECIAL LECTURE: On Tuesday, April 5, 2011, Scripps Institution of Oceanography hosted Nancy Rabalais, executive director and a professor at the Louisiana Universities Marine Consortium, who presented "Troubled Waters in the Gulf of Mexico" during the 12th annual Roger Revelle Commemorative Lecture, presented by the Ocean Studies Board, part of the U.S. National Research Council.
With the approach of the one-year anniversary of the Deepwater Horizon oil well blowout, Rabalais' lecture highlighted the challenges of developing and implementing large-scale restoration plans for the Gulf Coast ecosystem.
THE INITIAL RESPONSE
On April 20, the explosion and subsequent sinking of the oil rig Deepwater Horizon triggered a seafloor oil leak that had ejected at least six million gallons of oil into the Gulf of Mexico as of May 20. As the ensuing human and environmental catastrophe unfolded, Scripps research expertise was brought to bear to monitor and evaluate atmosphere and ocean conditions.
Scripps scientists performed a variety of research in the oil spill region:
Climate and Physical Oceanography
• Scripps researchers have conducted surveys of the Gulf of Mexico using Spray gliders. In response to the Deepwater Horizon incident, Scripps researchers diverted another Spray instrument originally intended for deployment off the California coast to the gulf in an attempt to assess the dimensions of the mass of leaking oil spreading in the gulf's water column. Researchers have outfitted the glider, which was deployed on June 7, with a fluorometer and an acoustic doppler profiler to image the dispersed oil by two different means.
• Oceanographers use various tools to track ocean currents for oil spills, including ocean buoys that follow the currents, satellites that measure ocean temperatures and measure winds, and a new technology called high-frequency radar that generates maps of ocean surface currents in near-real time. Scripps' Coastal Observing Research and Development Center (CORDC) helped prepare three radar stations operated by the University of Southern Mississippi to track the trajectory of the spilled oil in the Gulf of Mexico. Data is managed by Scripps to distribute these data to national agencies and first responders via the HF radar national network. Scripps is processing the data to a quality level that allows it to be directly used by NOAA HAZMAT officials in their spill trajectory model. CORDC would coordinate and distribute data from more HF radar units currently proposed for installation along the Gulf Coast.
• The region of the oil leak is known for its population of sperm whales along the continental shelf. Researchers in the Scripps Whale Acoustics Lab have deployed an instrument designed to capture animal sounds approximately eight nautical miles northwest of the Deepwater Horizon well, along with four other strategically determined sites around the Gulf of Mexico. The Scripps-developed high-frequency acoustic recording package, or HARP, has recorded marine mammal and other sounds in an effort to document which marine mammals are present in an area that had been consistently within the surface oil slick. By mid-October, preliminary analysis of the data shows that whales and dolphins remained in the vicinity of the well during the leak. Further details are pending. The installations have been supported by the Louisiana Universities Marine Consortium, the U.S. Navy, the Marine Mammal Commission and BP.
• Scripps scientists have studied the effects of marine contaminants in various locations around the world. Their research--from the wetlands to the deep sea--can help describe how pollutants can alter normal ecological processes. A Scripps researcher played a key role in assessing the ecological damage from a series of oil spills that devastated the coastlines of Panama (1968, 1986, and 1987), and a new video (courtesy of the Smithsonian Ocean Portal) features his compelling thoughts on lessons learned for the Deepwater Horizon oil spill.
• Scripps geochemists have extensively studied masses of methane hydrates on the gulf seafloor. The solid forms of hydrates are commonly co-located with subseafloor reservoirs of oil, especially in deep ocean regions where technology has enabled more widespread explorations. The researchers also study the numerous methane seeps that dot the gulf seafloor. Much of the methane locked beneath the seafloor that escapes through these seeps is oxidized by bacteria before it reaches the atmosphere, especially from greater depths. But the researchers have recently challenged assumptions about how much of the greenhouse gas can rise through the water column and reach the atmosphere. They found that methane can reach the sea surface from seeps as deep as 1,200 meters (3,900 feet), six times deeper than previously believed. Scripps geophysicists note that since the oil spill began, there is anecdotal evidence that numerous seeps have appeared on the adjacent seafloor, the result of accelerated formation of methane hydrates, which can rupture the seafloor.
• Scripps geophysicists have made extensive use of the kinds of remotely operated vehicles now being employed to cap the seafloor oil seep. ROVs are used in a number of seafloor exploratory missions, including an ongoing collaboration between Scripps and Norwegian oil company Statoil to assess the feasibility of sequestering carbon dioxide beneath the seafloor in a project taking place in the North Sea.