The Gulf versus Valdez: and the winner (or loser) is...

Tom Foreman | BIO
AC360° Correspondent

[cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2010/images/05/06/c1main.oil.slick.jpg caption="Closer scrutiny of the Exxon Valdez and Deepwater Horizon accidents, however, reveal profound differences along with the similarities. " width=300 height=169]

Cry havoc and unleash the experts! Over the past week or so, the public arena has been filled with the voices of people who know (or purport to know) precisely how bad the oil spill in the Gulf will ultimately be, and time and again, one word keeps coming up: Valdez. The worst oil spill in the nation’s history has loomed like a dark, dripping specter over all that has happened since that Gulf rig exploded and sank, killing close to a dozen people, and unleashing a torrent from a wellhead far beneath the waves.

Closer scrutiny of the Exxon Valdez and Deepwater Horizon accidents, however, reveal profound differences along with the similarities.

First, let’s consider the amount of oil. If we do the math on the Gulf spill, based on the official estimates of how much oil is pumping up every day, we end up with around 3.5 million gallons spilled so far. That’s a bit less than a third of the 11 million gallons spilled in Valdez. But there are important differences to note here. The Valdez spill came pretty much all at once. It rushed into the beautiful and pristine waters of Prince William Sound and went to shore immediately; giving neither marines mammals, birds, sea life, nor humans much time to react or try to stop it. The Gulf spill has been a gradual process. But it has been constant. We don’t know when it is going to end. And so, while it lags behind Valdez now, it could greatly surpass it if that big dome-under-the-sea plan does not stop the flow.

Second, let’s talk about the area being affected. Prince William Sound is about 11,000 square miles, and largely wrapped within surrounding land masses. The oil spilled there was held captive by geography, and that gave nature and/or luck little chance of helping out. The Gulf is around 615,000 square miles, and the location of the current spill is bounded on only one side by land. I’m not discounting the damage that oil can do in the open sea, but there is a reason we have talked so much about the marshlands and tidal areas; they, in many ways, are more critical to the life cycle of the Gulf because that’s where much of marine life begins or finds its food. To put it simply, if Valdez was like pouring a small cup of oil rapidly into a saucepan of water, the Deepwater Horizon incident is more like gradually pouring that same cup of oil into a wading pool. It is still serious, but the ability of the receiving body to absorb the blow is greater.

And third, what about chance? Some of the most sober scientists I have heard from on this say the simple truth of the Gulf spill right now can be summed up in four words: We do not know. Beyond a doubt, the Gulf spill has the potential of becoming an environmental disaster much worse than Valdez; but we don’t know if it will. The currents, the winds, a rogue storm, could suddenly push the oil toward shore with terrible results, even sweeping it around Florida and up the east coast…or could push it out to sea, disperse it, with little effect; we just don’t know. The well could keep leaking, or be stopped by week’s end; we don’t know.

We can look at the similarities between these two disasters and wring our hands, or look at the differences and be hopeful. Both are valid viewpoints. But which one will prove more sound? We do not know.