Tech: An oil spill off China's coast is the world's biggest since Deepwater Horizon — and it more than tripled in size over the weekend

A tanker carrying 122,000 tons of oil sank in the East China Sea, and investigators are only beginning to figure out the scale of the spill.

• An Iranian oil tanker carrying 122,000 tons of oil sank after it collided with a Hong Kong-based tanker in the East China Sea.
• The collision caused an explosion that sent thousands of tons of oil spilling into the ocean.
• The tanker was carrying condensate, a type of ultra-light crude oil that is more difficult to clean up than heavy crude oil.
• It's still not clear how big the spill will become, or what the impact on marine life will be.

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An oil spill off the coast of China is now the world's largest since the Deepwater Horizon disaster, which spilled millions of gallons of crude oil into the Gulf of Mexico in 2010.

A 900-foot Iranian oil tanker called the Sanchi was carrying over 122,000 tons of condensate — a refined form of ultra-light crude oil — when it collided with a Chinese cargo ship earlier this month. The crash caused the tanker to explode into flames, killing all 32 crew members aboard the ship and dumping millions of gallons of oil into the East China Sea. The tanker slipped beneath the waves on Sunday, eight days after the collision.

China's State Oceanic Administration said in a statement that the oil spill more than tripled in size over the weekend. There are currently more than three oil slicks with a surface area of approximately 332 square kilometers, or 128 miles. That's up from 101 square kilometers (38 square miles) on Wednesday. It's still not clear how large the spill will become, as much of the oil may have burned up in the initial collision.

Here's what the scene looks like:

The explosion that resulted from the crash sent flames shooting into the air, and the tanker continued burning for days afterwards.

Rescue ships sailed to the area and worked to extinguish the fire on the Sanchi after the collision.

The three rescue ships shown from above in this image provide a sense of the spill's scale.

Condensate spills are more difficult to clean up than heavy crude oil spills like Deepwater Horizon or Exxon Valdez.

The lighter oil is highly flammable, so traditional cleaning methods like containment and dispersal are too dangerous, The Atlantic reports.

Condensate also doesn't form a containable oil slick for long — the toxic substance can evaporate into the atmosphere or dissolve in water.

That poses a problem for fish, mammals, and other marine life. The substance can last in water for months and cause cancer and other complications at low concentrations, Buzzfeed reports.

The area where the Sanchi sank is an important fishing ground for blue crab and yellow croaker fish, according to Greenpeace.

But because scientists haven't dealt with many large condensate spills, it's not clear what the long-term effects will be on the environment.

Chinese, Japanese, and Iranian authorities launched search-and-rescue missions to find survivors and contain the flames, but reports suggest only three bodies have been found in the wreckage.

Source: The Guardian

A tanker carrying 122,000 tons of oil sank in the East China Sea, and investigators are only beginning to figure out the scale of the spill. Read Full Story