Sources of persistent sheen in Gulf of Mexico remain unknown

 HOUSTON, Dec. 18 (Xinhua) -- The U.S. Coast Guard said on Tuesday that underwater inspections¹ at the site of BP's 2010 rig explosion have failed to identify the sources of a persistent² sheen on the surface of the Gulf³ of Mexico.

Meanwhile, it said that recent inspections confirmed BP's Macondo well is secure and not leaking any oil, according to a report on the website of The Houston Chronicle.

The Coast Guard said that remote-operated vehicles investigating the sheen concluded operation on Saturday, and that no sources of leaking oil were identified.

However, investigators⁴ collected samples of a white, cloudy substance that appeared to be coming from several areas near the rig wreckage⁵. The substance is not believed to be oil, said the report.

A prior sheen was reported on Sept. 16 in waters near the site of the 2010 spill. It was later determined⁶ to have originated from a steel containment⁷ dome⁸ that was used in the early stages of the response in the 2010 spill to trap oil and methane⁹ hydrates from a leaking drill pipe in an attempt to funnel¹⁰ it to the surface.

A cap and plug were successfully put in place and no further oil emissions¹¹ from the containment dome have been observed, the Coast Guard said later.

The 2010 blowout of BP's Macondo well in the Gulf of Mexico triggered an explosion that killed 11 rig workers and unleashed¹² the worst oil spill in U.S. history.

1 inspections   

n.检查( inspection的名词复数 )；检验；视察；检阅

参考例句：

• Regular inspections are carried out at the prison. 经常有人来视察这座监狱。
• Government inspections ensure a high degree of uniformity in the standard of service. 政府检查确保了在服务标准方面的高度一致。 来自《简明英汉词典》

2 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

3 gulf   

n.海湾；深渊，鸿沟；分歧，隔阂

参考例句：

• The gulf between the two leaders cannot be bridged.两位领导人之间的鸿沟难以跨越。
• There is a gulf between the two cities.这两座城市间有个海湾。

4 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

5 wreckage   

n.（失事飞机等的）残骸，破坏，毁坏

参考例句：

• They hauled him clear of the wreckage.他们把他从形骸中拖出来。
• New states were born out of the wreckage of old colonial empires.新生国家从老殖民帝国的废墟中诞生。

6 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

7 containment   

n.阻止，遏制；容量

参考例句：

• Your list might include such things as cost containment,quality,or customer satisfaction.你的清单上应列有诸如成本控制、产品质量、客户满意程度等内容。
• Insularity and self-containment,it is argued,go hand in hand.他们争论说，心胸狭窄和自我封闭是并存的。

8 dome   

n.圆屋顶，拱顶

参考例句：

• The dome was supported by white marble columns.圆顶由白色大理石柱支撑着。
• They formed the dome with the tree's branches.他们用树枝搭成圆屋顶。

9 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

10 funnel   

n.漏斗；烟囱；v.汇集

参考例句：

• He poured the petrol into the car through a funnel.他用一个漏斗把汽油灌入汽车。
• I like the ship with a yellow funnel.我喜欢那条有黄烟囱的船。

11 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

12 unleashed   

v.把（感情、力量等）释放出来，发泄( unleash的过去式和过去分词 )

参考例句：

• The government's proposals unleashed a storm of protest in the press. 政府的提案引发了新闻界的抗议浪潮。
• The full force of his rage was unleashed against me. 他把所有的怒气都发泄在我身上。 来自《简明英汉词典》