It sounds like a Syfy movie or the next Michael Bay summer blockbuster. An oil spill covers the Gulf of Mexico at the same time that a tropical gathers strength in the Bahamas. As the tropical storms gathers strength, it takes up oil, which is ignited and leads to a blazing storm of fury pointed toward the mainland United States. Many worried about this before Hurricane Katrina and again after the 2010 Deepwater Horizon spill. But could it really happen? (And can you imagine the premiums for firecane insurance?) Let's take a look at the likelihood of this firestorm.
What Is Crude Oil?
Crude oil is made up of number of components, with "fuel oils" being separated by changes in temperature during the refining process. Once the oils are removed (the last will boil off at approximately 315 °C ), and what remains is tar, wax, and other organic industrial products. This is part of a typical refinement process that takes a single barrel of oil out of the earth and turns it into 36 gallons of fuel oil, with the residual hydrocarbons divided up to create asphalt or machine oils, or chemical reactants used in scientific experiments like sulfuric acid. The constituents of crude oil are less dense than water, causing it to float to the surface and stay there once released (looking similar to the gasoline "rainbows" you might see in a parking lot after it rains).
The 2010 Deepwater Horizon spill saw roughly 205 million gallons of crude oil spilled. That oil spread through the hurricane-ridden Gulf of Mexico at a pace of up to 60,000 barrels a day. Could this crude stuff get sucked into a hurricane?
The Vast Energy of a Hurricane
Hurricanes develop as tropical storms gather force over thousands of miles and several weeks, eventually reaching a magnitude where they release the equivalent of a 10 megaton nuclear bomb in heat every 20 minutes. The area hurricanes cover is phenomenal as well, with just they eye of the hurricane occupying an average of 40 miles, with the spiraling storms extending hundreds of miles more. Also remember that due to their size, hurricanes are very different visually when compared to tornadoes. You won't see the hurricane touching down like a tornado would - by the time a hurricane is near you, it has already engulfed you.
What Could Be the Spark?
Lightning. Enough said. The extremely flammable portions of crude oil have a very low flash point and evaporate or burn off quickly once the oil surfaces. The remaining crude oil components need a temperature of over 300 °C to change phases. Lightning immediately meets and exceeds these temperatures - one strike is all it would take to ignite the remaining oil, as lightning can reach temperatures of 30,000 °C (54,000 °F), enough to vaporize all of the fuel oil and further saturate the atmosphere. Lightning was noted as the cause of at least one severe fire in the aftermath of the Deepwater Horizon spill. There is one problem with the lightning hypothesis, however - lightning rarely comes along with hurricanes. When lightning does strike during a hurricane, it is typically confined to the eye wall of the hurricane. Even if the some of the crude oil caught fire, it would likely be extinguished before setting more crude oil aflame.
Oxygen consumption would also be an issue. Ever extinguish a candle by covering it? The flame was gone in a matter of seconds, right? A relatively large volume of oxygen in the air is necessary in order to sustain a flame. While the fire would theoretically have an inextinguishable supply of oxygen in the earth's atmosphere, the amount of oxygen available in a hurricane, due to wind and other variables, would be substantially diminished.
Blanketing a Coastal City in Oil
It is difficult to get an estimate on the volume of water in a hurricane, but flood estimates suggest over 200 billion gallons of water blanketed New Orleans alone during Hurricane Katrina. This dwarfs the amount of oil released in the Deepwater Horizon spill. An enormous amount of crude oil could be caught up within a hurricane and subsequently "dumped" ashore at landfall. This would be more likely than the firecane (and still a quite devastating) scenario, with crude oil blanketing sections of the impacted areas after it reaches shore.
Such an event conjures images of the Exxon Valdez oil spill and the environmental aftermath. This environmental impact juxtaposed with the necessity to maintain some sort of living conditions amidst the oil covered area would be a phenomenal logistics problem. Additionally, if the crude oil happened to pool in some areas, lightning and a plethora of other outside factors would be waiting to ignite the vapors above and the components below.
Verdict: You will not be living in this Michael Bay Movie
Hurricanes are just too big, both in size and energy, to significantly alter their characteristics. Sure, if the water in the Gulf of Mexico was replaced with crude oil, we would be in a ton of trouble and possibly consumed by an apocalyptic firecane, but I don't think there are enough liquified fossils deep in the Earth to pull this off. More likely, a hurricane could suck up and dump tons of crude on a nearby land area. As much as I want life to resemble a Michael Bay movie, it won't be this one.