Satellite Pictures: Gulf Oil Spill's Evolution

April 25: Oil Slick Grows, Gleams

Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA

As winds blow the oil southeast, away from land, on April 25, reflected sunlight turns the slick into an unfortunate silver lining (pictured in a NASA satellite image) for the clouds of crude now known to be gushing from the floor of the Gulf of Mexico.

At this point, the slick's "rainbow sheen" stretched about 40 by 30 miles (64 by 48 kilometers). The thick, dull layer of oil at the slick's southern edge (not visible), just above the seafloor leak site, measured roughly 16 miles (26 kilometers) long, according to a BP map.

The initial oil spill on April 22 had comprised about 8,400 gallons (31,800 liters) of oil, U.S. Coast Guard Petty Officer 3rd Class Tom Atkeson told National Geographic News on April 23, when the well was thought to have stopped leaking. That would have made it a "minor" spill, in the view of U.S. federal response agencies. (See "Oil-Spill Fears Subside at Rig-Explosion Site.")

But on April 25 the Coast Guard announced that remotely operated submersibles had found evidence that the pipe was leaking about 42,000 gallons (160,000 liters) of oil a day—a "very serious spill" and a threat to Gulf Coast ecology, Rear Adm. Mary Landry said at a press conference. (See "Oil Spill From Sunken Rig Site May Be Serious.")

May 4, 2010

April 26: Spill Stretches Toward Delta

Image courtesy ESA

Blown by welcome winds from the west-northwest, the Gulf of Mexico oil slick continued to stretch seaward on April 26. But it was also growing.

The slick's thin sheen—pictured in a European satellite radar image—was nearly a hundred miles (160 kilometers) wide at this point and about 21 miles (34 kilometers) from Louisiana's Mississippi Delta (at center-left in picture). The slick displayed thick, rusty "streamers" (picture of oil streamers) visible at closer distances, according to a BP map based on an early April 27 air survey.

On April 27, the U.S. Coast Guard announced they were considering controlled burns to keep the oil slick away from land. "We're prepared to use every tool in the tool kit," said Coast Guard Rear Adm. Mary Landry.

That tool kit, as of April 27, included miles of tubelike booms being floated offshore to stop surface oil from spreading; remotely operated vehicles, used in an unsuccessful attempt to shut a valve on the leaking pipe; and detergent-like chemicals that break oil into smaller droplets so it can be further broken down by natural processes.

Still to come: three four-story containment "domes" to be dropped atop the seafloor leaks in mid-May and a relief well, which should stop the spill for good but will take months to drill.

May 4, 2010

April 29: Ill Wind Spurs Oil's Landfall

Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA

Now roughly the size of Puerto Rico, the Gulf of Mexico oil slick, propelled in part by a shift in wind direction, snakes toward the coast as seen in an April 29 NASA satellite picture.

Later that day the oil would make its first landfall along Louisiana's "bird's foot" delta and barrier marshes, home to rare species. (Pictures: Gulf Oil Spill Hits Land—And Wildlife.)

On April 28 the U.S. Coast Guard increased its estimate of oil leaking daily by a factor of five, to 210,000 gallons (795,000 liters).

(Related blog: "Who's Still Spilling Oil in the Seas?")

May 4, 2010

May 1: Double Trouble for Spill Fighters

Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA

High winds delivered a double whammy on May 1, spawning rough waters that hampered oil-cleanup efforts at sea and pushing the slick (pictured in a NASA satellite image) farther into Louisiana's wetlands.

On April 30 the joint federal-industry response team said that more than 217,000 feet (66,142 meters) of boom had been deployed to try to protect these ecologically sensitive areas and that loud cannons had been fired to "haze" birds from the water's edge.

In addition to birds, many other coastal animals were reported at risk, including heavily furred animals such as otters and nutria, or semiaquatic rodents. Dolphins and whales can get skin irritations, and sea turtles are susceptible to oil ingestion, because they often come to the surface to feed.

The Gulf of Mexico oil spill comes at an especially bad time for sea turtles, which are entering their spring nesting season, conservationists said. (Read "Oil Spill Hits Gulf Coast Habitats.")

May 4, 2010

May 2: Spill Swirling Eastward

Image courtesy ESA

Spied by a European satellite, the Gulf oil slick spreads farther on May 2, with no immediate remedy in sight.

The same day U.S. President Barack Obama visited the Mississippi Delta in Louisiana to survey the response effort, and he declared the leak a "potentially unprecedented environmental disaster."

At its current estimated rate, the Deepwater Horizon oil spill could in a couple of months surpass the 11-million-gallon (42-million-liter) Exxon Valdez tanker disaster of 1989. (See "Exxon Valdez Photos: 20 Years On, Oil Remains.")

Meanwhile the slick continues to swirl and stretch, with some experts sounding a tentative alarm for even U.S. East Coast beaches.

May 4, 2010