Beneath the Surface: if only it were just a nightmare
After Oceanographers, Scientists and Official recognition of underwater plumes, Undersea robot aimed for 3-D image of BP oil plume.
By Xavier Briand, Reuters.
Scientists geared up on June 16th, for a 12-day trip in the Gulf of Mexico with an undersea robot they hope will capture 3-D images of oil plumes from the BP spill.
Oceanographers and others have been monitoring the plumes of oil, gas and dispersant chemicals coming from the broken BP wellhead since soon after the April 20 explosion on the Deepwater Horizon drilling platform.
An underwater video camera shows the oil gushing from the wellhead on the sea floor, and aerial and ship observations have charted where the spill has drifted on the water’s surface.
But the exact location and the extent of oil and other chemicals in the water column have been harder to determine.
The scientists’ robotic vehicle would try to figure out how big the plume is, where it is and what it is made of, said Christopher Reddy, director of the Coastal Ocean Institute at Woods Hole Oceanographic Institution.
“The technology that we’re bringing to bear is perhaps more suited to interrogate the size, shape and chemical composition of those plumes than what traditional oceanographers have been using,” Reddy said by telephone from St. Petersburg, Florida.
The robot, called Sentry, can be put over the side of a research vessel for 14 to 18 hours at a time, with a mass spectrometer that can “sniff for oil,” Reddy said.
Circling The Plume
Unlike robotic vehicles that are directed remotely by computer, Sentry can change course by itself, like a bloodhound following a scent, to track oil, gas or other hydrocarbons leaking from the sea bottom, Reddy said.
The Sentry AUV (autonomous underwater vehicle) is on the research vessel Endeavor, a 184-foot (56-meter) oceanographic ship owned by the U.S. National Science Foundation and operated by the University of Rhode Island.
Reddy is among some 30 scientists and crew set off from the Florida Gulf coast for the area near the spill, focusing on the so-called southwest plume that has been seen about 20 miles south of the wellhead.
Instead of sensors dropped over the side of boats almost like fishing lines, which can observe only a small portion of the plume, Sentry would move around on its own to circle the oil, move up and down or go through it.
“At the end of the day, we’ll have a three-dimensional, almost holographical image of the plume,” Reddy said.
National Science Foundation Article
Beneath The Surface
OIL PLUME EXPLAINED
By Donald Reinhardt, Professor of Georgia State University in Atlanta, Georgia.
“Oil and water don’t mix” but “oil and water and dispersants do mix” and then large underwater oil plumes will exist and wreak havoc wherever they go.
The BP Gulf of Mexico oil spill of April 20, 2010 at the Deepwater Horizon Rig in Mississippi Canyon 252 is a historic, economic, environmental, engineering and scientific event of major significance. The spill is already one of the greatest man-made and natural disasters in American history with hundreds of thousands gallons of Louisiana crude streaming daily into the Gulf waters from one mile below. Deepwater Horizon is an ongoing story that involves: an exploded oil rig, 11 dead workers, a damaged riser pipe, multiple attempts by robots to control and cap the damaged pipe and BOP (Blow Out Protector), oil contamination of living and non-living things, and underwater oil plumes.
Oil, Water and Oil Dispersants Mix Well
Oil dispersants are useful to separate or dissociate large masses of oil into smaller patches. The EPA has approved 18 different dispersant products for oil spill situations similar to BP’s Deepwater Horizon spill in the Gulf of Mexico.
BP is using Nalco’s COREXIT dispersant at the damaged BOP site. Here escaping oil actively mixes with BP’s pumped-down dispersant about 5000 feet below the Gulf’s water surface. The oil and dispersant interact with the saltwater to form a oil-dispersant-water combination or mixture. The complex oil-dispersant-water mixture is too heavy to float completely upward, but not heavy enough to sink down to the bottom. Therefore, the oil plume remains in the water column.
Any oil that floats to the surface has not mixed with dispersant or has separated from the dispersant. Floating oil has a lower density than water. This oil remains on the surface unless a dispersant is dropped onto the oil by aircraft or from dispersant boats . When this is done the oil will sink below the surface.
Oil Plumes are Oil-Dispersant-Water Mixtures
Despite protestations from some (BP), oil plumes are very real. These oil plumes have been independently observed and proven to exist. Forensic oil and dispersant chemical analyses of different Gulf oil plume samples can reveal the true nature and source of these documented oil plumes. Jane Lubchenko, Head of NOAA, held a briefing in Washington (Npr.org) and confirmed that one oil plume, some 3000 feet deep and 40 miles northeast of the Deepwater Horizon drill site, represents oil from the BP rig accident.
Oil plumes are made even more real when there are large masses of oil mixed deep down in the water with massive amounts of dispersants as has occurred in the BPO oil spill of 2010. These oil plumes can migrate and be carried far and wide by various underwater currents.
What Happens to Oil Plumes?
As plumes travel within water columns they tend to separate or dissemble into smaller and smaller pieces or fragments. Various plumes that form are complex combinations of different amounts and types of the original crude oil, saltwater and dispersant. Some of the oil breaks free of dispersant and floats to the surface. Some of the plume mixture attaches to living seaweed, phytoplankton, zooplankton, fish, shrimp and other life forms.
Some of the plume mixture attaches to dead organic matter such as submerged wood, dead animals and plants. Some of this oil complex settles downward toward the bottom of the Gulf and other portions of oil and oil-dispersant move to beaches, marshes and waterways where they make landfall. Some of the smaller plume combinations are digested by microbes. Some of the plume complex is ingested by crabs, shrimp, and fish. Some contaminated fish may be eaten by pelicans, gulls and other Gulf birds.
How does the oil plume looks like? in Washington Post
Recent Tests confirm spreading of plume, in NY Times
