Whatever turns out to be the case, the incident again highlights the vulnerability of the world’s most important energy waterway, one which Iran has periodically threatened to block, in retaliation for international pressure over its nuclear program.
Up to 40 percent of the world’s daily oil supply – including three-quarters of Japan’s needs – traverses the Persian Gulf’s Strait of Hormuz chokepoint en route to markets in the West and Asia. Situated between Iran, Oman and the United Arab Emirates, the channel is less than 30 miles across at its narrowest point.
The 160,000-ton M. Star, a Japanese-owned, Marshall islands-flagged supertanker, was anchored off Fujairah in the UAE on Thursday, undergoing inspection of its damaged hull.
A photo released by the UAE’s WAM news agency showed a large, square-shaped dent in the vessel’s hull, near the waterline.
The unexplained incident in Omani waters early Wednesday morning was first described by the owners, Mitsui O.S.K. Lines (MOL), as “an explosion which seemed to be an attack from external sources.” The statement that prompted speculation that pirates, terrorists or a military force may have been responsible.
MOL said one of the crew was lightly injured, but none of the 270,200 tons of crude oil taken onboard in the UAE the previous day had leaked from the damaged hull.
The “explosion” theory appeared to be backed up by a statement from the Japanese transportation ministry, which said one of the 31-member crew reported seeing “a flash on the horizon immediately before the blast.”
But maritime officials in the UAE, Iran and Oman said that the M. Star had been hit by a large wave. A UAE port captain was quoted as telling local media the wave was “a result of seismic shock” while an Iranian official cited an “earthquake.” One report cited the Omani coastguard as saying the wave was triggered by a 3.2 magnitude earthquake in the Iranian port city of Bandar Abbas.
The U.S. Geological Survey, which monitors earthquakes worldwide and lists all events 2.5 magnitude and bigger, has no report of any quake in that region in recent days. The most recent quake in the region was a 4.8 magnitude tremor on Saturday, July 24, in southern Iran.
The Pacific Tsunami Warning Center also has had no tsunami warnings in the entire Indian Ocean region since June 12. Prof. Mike Sandiford, earthquake expert and director the Melbourne Energy Institute at the University of Melbourne in Australia, said Thursday there was “zero chance” of a wave being caused by a quake four days earlier. A “submarine slope failure” – an underwater landslide – could be a possibility, he said.
MOL was sticking to its guns Thursday, with an official telling a briefing in Tokyo a quake-induced wave was unlikely the cause of the incident, and that the damage suggested the ship had been hit from the outside. A spokesman for the U.S. Navy Fifth Fleet, based in Bahrain, said the ship had reported by radio that an “explosion” had occurred. The Navy had offered assistance, but the ship’s master determined it was not necessary. The ship made its way to Fujairah under its own steam.
The spokesman said the M. Star incident did not affect the shipping lane. State Department spokesman Philip Crowley said the U.S. had no information to suggest that the event was anything other than an accident but would be “watching carefully as more information comes in on that.”
Piracy, terrorism, military action
Maritime security experts have long warned of the danger of a terrorist or pirate attack on a supertanker in one of the world’s strategic sea chokepoints, which include the Strait of Hormuz, the Malacca Strait between Singapore, Malaysia and Indonesia, Gibraltar and the Panama and Suez canals.
Apart from the environmental impact should a tanker’s hull be intentionally or accidentally breached, the economic cost and disruption of an incident blocking a crucial waterway for a period of time would be massive.
Islamist terrorists have targeted ships before. The destroyer USS Cole< was bombed in Yemen’s Aden port in 2000, an attack that killed 17 sailors, and boat-borne suicide bombers attacked the French oil tanker Limburg off the coast of Yemen in 2002.
In 2004 two sailors died when a U.S. Navy patrol vessel intercepted a dhow heading for an oil terminal in Iraq and the dhow exploded in an apparent suicide bombing. In 2005, two U.S. Navy ships docked in Jordan’s Aqaba port were targeted by Katyusha rockets. Al-Qaeda-affiliated terrorists claimed responsibility.
In what is believed to be the deadliest terrorist attack at sea, an al-Qaeda linked group in the Philippines bombed the Superferry 14 passenger ferry near Manila in 2004, killing 116 people.
The Iranian government and its Islamic Revolution Guards Corps (IRGC) has on several occasions in recent years threatened to close the Strait of Hormuz, typically in response to Western statements or pressure relating to its nuclear activities.
Last month Tehran warned that if Iranian ships were stopped and searched as part of a sanctions regime it would retaliate by stopping foreign ships in the Gulf and Strait of Hormuz.
In 2008 Iranian gunboats approached U.S. warships in the Gulf in what the Pentagon said was a deliberately provocative maneuver.
Oil tankers traversing the strait do so along two-mile wide channels demarcated in each direction, sailing through Iranian territorial waters in the north and Omani waters in the south.
Under the U.N. Convention on the Law of the Sea, ships have the right of “innocent passage” through the territorial seas of a coastal state.
In the event of the chokepoint’s closure, an alternative route for the oil would be via the 745-mile East-West pipeline across Saudi Arabia to the Red Sea, from where tankers would have to sail north through the Suez canal or south through the Gulf of Aden and piracy-affected Horn of Africa waters.
Alternative routes would also be longer, further pushing up costs, the EIA says.