The US Coast Guard said Friday that an anchor likely damaged an underwater oil pipeline in Southern California many months to a year before a break spilled tens of thousands of gallons of petroleum.
Hastened Investigation
According to Capt. Jason Neubauer, commander of the Coast Guard's office of investigation and analysis, a giant vessel may have impacted the enormous pipeline, fractured the concrete casing but not necessarily produced the narrow fracture from which oil poured last weekend.
The extended timetable was predicated in part on discovering marine vegetation on the pipe during an underwater survey.
He noted that the pipe, which was discovered intact last October, may have been struck by other ships' anchors multiple times throughout the period.
However, no ships have been discovered.
"For the entire year, we're going to be watching at every vessel movement over that pipeline and every close incursion from the anchor," the skipper added.
Pipeline Conditions
According to Neubauer, the pipeline was dragged as far as 105 feet down the seabed.
He believes this implies a huge vessel was involved. Cargo ships carrying multiton anchors pass through the region regularly from Los Angeles and Long Beach ports.
Beaches were polluted, and seabirds were killed as a result of the spill.
According to an Associated Press examination of more than 10,000 complaints submitted to federal authorities, at least 17 pipeline incidents carrying crude oil or other hazardous liquids have been connected to anchor strikes or suspected anchor strikes since 1986.
Studying Government Records
According to government records, in certain situations, such as the 2012 from an ExxonMobil pipeline in Louisiana's shallow Barataria Bay, a direct impact by a barge or other boat was also considered a possibility. However, an anchor strike is never clearly confirmed.
The evidence of an anchor hit was evident in others. For example, during Hurricane Andrew in 1992, a drifting drilling rig pulled a 30,000-pound anchor across a Texaco pipeline in the Gulf of Mexico, producing a dent that subsequently blew open when the line was re-started.
In the Gulf of Mexico in 2003, a 7,000-pound anchor was discovered approximately 10 feet from a minor spill on a Shell Oil pipeline.
Although a trench in the sandy bottom appears to lead to a bend in the underwater line in a Coast Guard video published Thursday, experts have differed on the importance of the brief, blurry pictures. A tiny, 13-inch-long break in the bar was shown in an earlier video.
Considering Other Factors
The second video appears to show a trench in the seabed formed by a dragging anchor leading to the broken pipeline, according to Robert Bea, an engineering professor at the University of California, Berkeley, and a former Shell Oil engineer.
Other factors, such as water currents in the seabed, are anticipated to be considered by investigators as possible causes of the pipe's movement and damage.
It'll take some time.
"Validation - or corroboration - of the findings from the analysis is required. This procedure may result in even more inquiries, "Bea remarked. "Internal pressures in the pipeline created the crack, based on the form of the trial. But, if that's the case, how come the pipeline didn't burst? "when was it?
According to Frank G. Adams, president of Houston-based Interface Consulting International, "doesn't necessarily seem like anchor damage," he wrote in an email.
When an anchor or other large item strikes a pipeline, "physical damage occurs, which might lead to a fracture," he added.
Related Article: Disastrous California Oil Spill Cleanup Faces More Challenge Due to Stormy Weather
Initial Reports
The initial reports of a probable spill off Huntington Beach surfaced on Friday evening, but the leak wasn't located until the morning of Saturday. While the exact extent of the leak is unknown, the Coast Guard amended their estimates on Thursday to include at least 25,000 gallons and no more than 132,000 gallons.
About 5,500 gallons of crude oil were retrieved from the water, according to the Coast Guard. In addition, small quantities of oil have been reported washing up on the beach in San Diego County, some 50 miles from the original spill location.
Local health authorities stated Friday that air tests from locations where oil might spread are below background levels - similar to air quality on a regular day - and that the contaminants found are below California health requirements.
The impact on wildlife has been minor thus far - 10 dead birds and another 25 found alive and treated - but environmentalists warn that the long-term consequences might be far worse. While cleanup on the beach continues, certain Laguna Beach beaches reopened on Friday. However, the public can still enter the ocean.
Critical Hours
Investigators are trying to figure out what happened in the critical hours after the initial indications of an oil spill.
The tiny hole visible in one video might explain why there were symptoms of an oil slick on Friday night, yet the leak went unnoticed for more than 12 hours by the pipeline operator.
When pipelines break catastrophically, the breach is generally considerably larger, referred to in the industry as a "fish mouth" rupture because it gapes out like a fish's mouth, he added.
Amplify Energy, a Houston-based firm that owns and manages three offshore oil rigs as well as a pipeline south of Los Angeles, claimed it was unaware of the leak until its workers saw an oil sheen on the sea at 8:09 a.m. on Saturday.
According to authorities, the leak happened roughly 5 miles offshore at a depth of around 98 feet. According to Amplify CEO Martyn Willsher, a 4,000-foot piece of the pipeline was displaced 105 feet and twisted back like a bowstring.
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