Mystery lingers around cause of California oil pipeline leak

HUNTINGTON BEACH, Calif. (AP) — Investigators searching for the cause of an oil pipeline break off the Southern California coast have pointed to the possibility that a ship anchor dragged the line across the seabed and cracked it, but two videos released so far provide only tantalizing clues about what might have happened 100 feet (30 meters) below the ocean surface.

A Coast Guard video released Thursday appears to show a trench in the seafloor leading to a bend in the submerged line, but experts offered varied opinions of the significance of the brief, grainy shots. An earlier video revealed a 13-inch (33-centimeter) rupture in the line, but the pipe showed no evidence of damage that they said would be expected from a collision with a multi-ton anchor from cargo ships that routinely move through the area off the ports of Los Angeles and Long Beach.

The slight bow in the line displayed in one video “doesn’t necessarily look like anchor damage,” Frank G. Adams, president of Houston-based Interface Consulting International, said in an email. When a pipeline is hit by an anchor or other heavy object “that typically results in physical damage that may lead to a fracture.”

Ramanan Krishnamoorti, a petroleum engineering professor at the University of Houston, said he considered the video that runs along a bend in the line “revealing.”

"It seems to me you’ve got something that was dragged in the sand that might have impacted the pipeline,” he said. However, he remained puzzled that the leak came from a crack and not a larger gash, assuming it was hit by an anchor or some other object.

Key questions remain: Could the line have been hit days before the leak started? What ship is responsible? And if a ship anchor is not the culprit, what else could it be?

Investigators,...