The population density and the topography are just 2 of the different factors to consider.
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The BP spill, at a depth of nearly 5,000 feet, is proving more complicated to choke off than Ixtoc, a shallow-water rig about 150 feet deep. The Ixtoc well could be accessed directly, while the Deepwater spill must be combated remotely, using robots to wield clamps, saws and other tools while monitoring the action by video feed.
"They could fight Ixtoc from and at the surface," said Robert Bea, a professor of engineering at University of California at Berkeley who has studied offshore drilling for 55 years and worked for Pemex for a number of years. For Deepwater, "they must fight from the sea floor remotely, from the sea surface miles above."
Most recently, BP tried to stop the gusher by pumping in heavy drilling mud and cement. The tactic, called a "top kill," had never been tried 5,000 feet underwater. It didn't work.
The good news is the Ixtoc experience suggests the Gulf of Mexico has natural properties that help it cope with massive oil spills, scientists say. Warm waters and sunlight helped break down the oil faster than many expected. Weathering reduced much of the oil into tar balls by the time it reached Texas.
Two decades after the Ixtoc disaster, marine biologist Wes Tunnell sank his diving knife into an area where he had spotted a tar patch just after the spill. The blade came out black and tarry but the hardened surface of the patch was under sand, shells and algae that had completely covered it.
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"No one else would know that it was anything other than a rock ledge," said Tunnell of Harte Research Institute for Gulf of Mexico Studies at Texas A&M University.
"I think that the Gulf of Mexico is hugely resilient, or at least it was 30 years ago. We've insulted it a lot since then in various ways."The Gulf has also long dealt with oil that naturally seeps from the seafloor. Some experts estimate that tens of millions of gallons seep into the Gulf from natural up-wellings each year, fostering large populations of oil-eating bacteria and microorganisms.
However, it is unclear how much any of that will help this time around.
The Deepwater spill is closer to sensitive coastlines than Ixtoc was. And it is affecting Louisiana marshlands that are more sensitive than the
more sparsely populated Texan and Mexican coastlines Ixtoc reached."Obviously there were some helping factors — nature, climate, current — that in the end helped people (with Ixtoc) so that's good news," said Patzek. "However ... the Ixtoc well seemed to have been a little farther out from sensitive places."
The depth of the BP spill could also complicate the Gulf's ability to cope.
The oil-eating bacterial populations are located mainly on the surface or near shore, where the Ixtoc oil appeared. BP has tried to break up the oil deep underwater, pumping chemical dispersants directly into the damaged well.
That could be a mistake, said Larry McKinney, the director of the Harte Research Institute.
While chemically dispersing the oil keeps the spill less visible and ugly than Ixtoc, it prevents the oil from floating up to the surface where wind, waves, bacteria and sunlight could help break it up, he said. And some environmentalists question the safety of the dispersant itself.http://www.brownsvilleherald.com/articles/mexico-112879-city-oil.htmlSome other differences:
That spill had a far lesser environmental impact than the BP/Halliburton/Deepwater Horizon gusher has already had. Firstly, the leak was in the Bay of Campeche, so it was effectively isolated by land on 3 sides and favorable wind patterns from the open side; its encroachment on the Gulf proper was much easier to track, anticipate and defend.
Conversely, the BP/Halliburton/Deepwater Horizon gusher is open to the Gulf on 3 sides, and the open-face coastline of the United States on the 4th side, and has no barrier between the slick and the Gulf Loop current which carries the oil at an accelerated pace to the Florida Keys, the Caribbean and the Gulf Stream, North Atlantic Current and South Atlantic Current, which can transport the toxic sludge pretty much anywhere in two hemispheres.
A great portion of the Ixtoc I BURNED OFF! There was a continuous fire that consumed a huge portion of the oil that therefore was not able to infect, degrade or destroy the aquatic environment.
Compared to the 5,000-foot depth of the BP/Halliburton/Deepwater Horizon spill, the Ixtoc I was in much shallower waters, about 160 feet, still within the reach of divers. So the pressure relief efforts and the ultimate capping of the spill had a much higher chance of success - and it STILL took TEN MONTHS. There is no guarantee that the relied wells aggressively touted as an August completion will work. The idea that this gusher will be capped any time this year is pretty optimistic.
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This ignores the economic impact in the comparison. The wildlife in the Bay of Campeche and adjacent areas of the Gulf did rebound, but only because they closed all commercial and recreational fishing for both finfish and shellfish in the entire area for a measure of years.
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The surrounding coast of the Bay of Campeche, as well as the extending Mexican coastline reached by the spill was almost all sandy beaches. Easy to clean and not supportive of or critical to many forms of wildlife. The BP/Halliburton/Deepwater Horizon gusher is surrounded by wetlands - in fact they make up most of the coastal areas the spill will reach from Texas to Florida. This spill has already contaminated more wetlands that were ever touched by Ixtoc I.
Beaches are relatively easy to clean, and oil rarely reaches the dunes vegetation set well beyond the highest tide line. And if you don't clean them, they weather into tar and then to asphalt, making it even easier to clean. But every minute in wetland area is deadly. Wetland contamination is extremely difficult to reverse. As wetland plants' roots suffocate and degrade, the sediments they hold in place wash away, leaving nothing for new growth to anchor in. Only a few mangrove areas were lost in Ixtoc I - more have already been contaminated in the BP/Halliburton/Deepwater Horizon spill and will be lost just in Louisiana where it's made landfall.
Even with all these relative "advantages", it took 5 years to "complete" the clean-up for the Ixtoc I - I put "complete" in quotes because they still have not cleaned it all up - but the portions on beaches that were not cleaned up had degraded into asphalt and were left there, eventually losing most of the toxicity through evaporation (which was then dispersed piecemeal throughout the bay and countryside in the form of tainted & acid rain).
The environmental destruction all has to do with the density and diversity of the surrounding flora & fauna. The Ixtoc I had relatively small ecological impact because of all the reasons listed above, but also because of the lesser density of wildlife in the area.
For instance, due to the beach topography of the surrounding coasts, there were "only" up to 10,000 seabirds killed by Ixtoc I; conversely, an estimated 250,000 seabirds were killed by the Valdez spill because it occurred adjacent to and destroyed huge tracks of nesting grounds. And as has been widely reported in the news, the BP/Halliburton/Deepwater Horizon gusher has made landfall in one of the biggest seabird nesting rookeries in the Gulf.
The most imperiled animals in the Ixtoc I spill were the Kemp's Ridley sea turtles, as the spill surrounded Rancho Nuevo, one of the few nesting sites in the world for the species. Thousands of baby sea turtles were airlifted to a clean portion of the Gulf of Mexico to help save the rare species - to date, nothing has been done to save any species in the BP/Halliburton/Deepwater Horizon spill, short of picking up individual stranded animals as they're found, cleaning them off and re-releasing them some miles down-shore outside the immediate spill zone (something that will have limited effect, since birds, turtles, etc., are instinctively programmed to return to the same nesting site, so they will try to migrate back to the spill area from whence they were temporarily rescued).
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http://www.businessweek.com/news/2010-04-30/relief-well-plan-was-used-in-worst-blowout-ever-took-9-months.htmlhttp://www.gatorcountry.com/swampgas/showthread.php?p=4056401#ixzz0r0gi7iff