East Coast Earthquake 8/23/2011: Rapid Reaction

At around 1:51pm, a magnitude 5.8 earthquake struck about 85 miles southwest of Washington, D.C. Judging from social media postings and talking to friends, approximately 20 to 30 seconds of noticeable shaking was felt in the D.C. metro area within a minute of the earthquake. Seismic activity propagated up and down the East Coast; shaking was felt in Philadelphia by 1:52pm, New York City by 1:53pm, and eventually up to Boston, Cape Cod, and even Toronto.

Question 1: Is the the Apocalypse?

No, it is not. This earthquake occurred in a region known as the Central Virginia Seismic Zone, where small earthquake activity has been commonly noticed since at least 1774. The largest previous earthquake in the Central Virginia Seismic Zone was a magnitude 4.8 in 1875. More recently, a magnitude 4.5 earthquake struck the Central Virginia Seismic Zone on December 9th, 2003. This will undoubtedly be the largest recorded earthquake within the Central Virginia Seismic Zone; however, if its current designation of a magnitude 5.8 holds, it will not be the strongest earthquake in the history of Virginia. That distinction belongs to the Giles County earthquake of 1897, a magnitude 5.9 centered near the West Virginia border that was felt all the way in Cleveland, Indianapolis, and Atlanta.

Question 2: How worried should I be about aftershocks?

Probably not too worried, but be cautious. From a cursory look through USGS earthquake records, previous Central Virginia Seismic Zone earthquakes (the 1875 and 2003 earthquakes) show little record of significant aftershocks. At the time my writing, there have already been two aftershocks, a magnitude 2.8 at 2:46pm Eastern Time and a magnitude 2.2 at 3:20pm Eastern Time (Figure 1). An aftershock would likely need to be at least magnitude 3 to be felt in the greater D.C. region. For comparison, the Giles Country Earthquake of 1897 produced aftershocks for a week after the earthquake, although every earthquake is different and we can't be sure of what features translate between earthquakes.

Figure 1. Seismic Activity in the Central Virginia Seismic Zone as of 4:14pm, 8/23/2011.

Question 3. Why did this happen? I thought earthquakes only occurred in California.

Earthquakes can occur anywhere there are faults, regardless of the age of the faults. Many faults are concentrated today at plate boundaries, where large portions of the Earth's crust join and grind against each other. California is the first and foremost example of this; the Pacific plate meets the North American plate at California, and the geologic happenings associated with this juncture lead to a lot of seismic activity. The Eastern Seaboard of the US is a geologically calm area today, but that was not always the case; when the Appalachian Mountains formed around over 200 million years ago, there was an active plate boundary just off the East Coast. Faults existed all along the East Coast then, and many of those faults are still preserved in the bedrock today. We don't know what triggers them to reactivate, but occasionally they do. And because they happen so less frequently on the East Coast than in California, we are always in for a surprise when they do occur.

The obligatory hands-on-the-face, "what-the-heck-is-going-on" East Coaster in an Earthquake look. Courtesy of New York Times.

Uncertainly Certain: The fossil fuel(less) future of human society

Today, I drove fifteen miles to work in my car, packed my lunch with plastic bags, used my plastic ID to get into my office, where I immediately sat down and turned on my (you guessed it) plastic-cased computer powered by an always-faithful supply of electricity. The common thread? Fossil fuels. Gasoline powers the internal combustion engine in my car, refined oil is used to create the omnipresent plastics on which we so rely, and the burning of fossil fuels is the dominant source of electricity for the world. Moreso than any other factor, it is this preponderance of fossil fuel applications that epitomizes the modern industrial era, an era that has—despite the invention of computers and the internet—remained fundamentally knotted to fossil fuels for over a century now.

My generation sits at an uncomfortable tipping point in this equation. Common sense dictates that the supply of fossil fuels is not limitless, and the extraction of fossil fuels—as the Deepwater Horizon event so (non)neatly demonstrates—is far from harmless. Legacies of environmental imperilment and callous mismanagement by drilling companies aside, there will come a time when the impetus to separate human society from fossil fuel use derives not from issues of sustainability, but from issues of necessity. The future of fossil fuels in human society is what I term “uncertainly certain”: certain in the sense that we will run out, uncertain in the sense of timing.

When will we run out? Well, there are quite a few different fossil fuels, and the answer is more suited to a book than a blog. But let’s focus on one in particular: oil. Oil is a vitally important substance used dominantly for transportation, industrial, residential, and utility applications. In 2008, nearly 71% of oil consumed in the United States—the world’s greatest consumer of oil, no less—went toward the transportation sector. If we were to run out of oil tomorrow, our transportation system would shut down, 8.1 million households in the US would freeze come winter, and a full 35% of the world's energy supply would disappear. The magnitude of such an event was not lost on the scientific community; the studies of oil reserves and expectations for future supply have existed for quite some time. Here I want to introduce the most widely circulated theory of our future oil supply—“peak oil”—analyze its validity in the face of strong criticisms, and perhaps provide some idea as to what we can expect for industry 50 years from now. If you can’t read any further, here’s a short summary: if the world is the same, we’re probably screwed.

Peak Oil

Marion King Hubbert was a research scientist at Shell Oil Company, professor at Columbia University, and vaguely looked like the late Burt Reynolds (at least to me). In 1956 he postulated what is now known as the “peak oil” theory: for any well, oil field, or even nation, the production of oil follows a bell-shaped curve. Great, who cares? No one did at the time, until Hubbert predicted that U.S. oil production would peak between 1965 and 1970…and he nailed it.

Source: S. Foucher

The important concept behind the “bell curve” shape for oil production is that there is a single point where oil production is at its maximum before it declines; this point is referred to as “peak oil”. This is significant due to issues of supply and demand. Demand for oil has almost constantly risen in modern times: Between 1965 and 2009, global oil consumption increased by 270% and shows no sign of slacking in the near future. As peak oil represents the time when the supply of oil is at its highest, it represents the timing of a fundamental shift between the supply and demand of oil. After peak oil is reached, oil supply can no longer grow to meet demand. As basic economics shows us, this means oil prices will skyrocket.

Show me the money

Peak oil theory has successfully predicted oil production from individual wells, oil fields, and nation-states, but has been criticized when applied at the regional or global level. One of the strongest counter-arguments states that peak oil theory is misleading because it is fundamentally insensitive to price. Quite simply, the amount of oil that a company can recover at a profit depends on the price at which they can sell the oil. Rising oil prices make the recovery of oil at more expensive/risky sites (hint hint Deepwater Horizon) economically viable, allowing for an increase in global production during higher prices.

Fortunately, whether oil price has any relation to oil production is easily testable. Figure 1 below plots inflation-adjusted crude oil price and total world oil production for the past few decades.

Figure 1

While both show generally increasing trends, especially after the early 1980s, they do not appear either very consistent or coherent. A scatter plot, Figure 2, reinforces this conclusion.

Figure 2

Remember I warned in a previous entry that correlation does not imply causation. Well, the opposite is not the case; a lack of correlation does indeed imply a lack of causation. If one variable forced another, we would expect them to show at the least a meaningful correlation (e.g. not an r-squared of 0.05). Therefore, because oil price and oil production do not correlate, oil production is in actuality price insensitive, at least between 1970 and present. This is an especially surprising result, as you would think oil companies would ramp up production during high oil prices to maximize profits. It is likely they are unable to; I dare say increasing oil production is not as simple as flicking a switch.

Have we reached peak oil?

Several more surprising results follow from this. First, looking back at Figure 1, it appears as if the rate of increase in oil production has slowed significantly in the last several years.

Uh oh:

The previous image shows the results of a compilation of oil production models (yellow path) indicating that we either have already reached peak oil or will reach it within the next couple years. Also noteworthy is that the International Energy Agency, or IEA, have significantly reduced their expectations for future oil production from 2006 to 2008, and now suggest that we will reach peak oil by around 2030. Note also that their forecast now underestimates the population model, which assumes that oil production is tied to the world population. Either way, it appears that in the coming decade, for the first time in recent history, population growth will outstrip global oil production.

There are other indications we may be approaching peak oil, as well. Figure 3 shows that, since 2000, both the average depth of “exploratory” wells drilled in search of untapped oil reserves and the cost of recovery of a barrel of oil have increased dramatically in the U.S.

Figure 3

Combined, these indicate that we are searching deeper than ever before for more oil, and at greater cost. Coincident with this greater cost is greater risk, as surely the Deepwater Horizon incident has awakened us to. In my last post, I argued that sealing off the Deepwater Horizon wellhead would be a nearly impossible feat due to the pressure at which the oil and gas mixture is escaping. Remember that this pressure relates in the first order to the depth at which the well was drilled. If we keep drilling deeper and deeper in search of more fossil fuels, we will be attempting to tap into fossil fuel deposits at higher and higher pressures, and as such we should expect greater risk and a greater chance for major, nearly uncontrollable environmental disasters like the Deepwater Horizon incident.

What about the future of fossil fuels in human society? It is safe, for now. Although oil production may be price insensitive, high oil prices have made other methods for extraction feasible (e.g. oil sands and oil shales), unlocking reservoirs that equal to or dwarf the largest current oil reserves. Further, even if we reach peak oil within the next decade, it will still be some time until oil reserves become depleted enough to consider an “oil-free future” as a reality.

Nevertheless, there is something we should be very concerned about: while oil supply may be close to leveling off, oil demand is far from level. Rising industrial nations like China and India will force a major rebalancing of world oil supplies; between 1995 and 2005, U.S. oil consumption increased 17%, while China’s more than doubled. Global energy consumption is projected to increase by nearly 50% by 2035, with oil use alone increasing by 22%. Such increases in demand without meaningful increases in oil supply will surely pressure oil prices upward. In closing, although we should not fear running out of oil, our society is so tied to oil that even the threat of a shortfall could wreak havoc. Although the environmental argument for an oil-free future is a strong one, there is a much better argument lurking beneath the surface: We’re going to have to face it someday, so we might as well start getting prepared now.

Agree? Disagree? Think I’m full of it? Post your comments below and I’ll try to answer them. Also, I’ve included some links I found very useful if this topic interests you:

The 2005 Hirsch Report: Peaking of World Oil Production- Impacts, Mitigation & Risk Management (U.S. Department of Energy).

BP’s 2010 Stastictical Review of World Energy (yeah, I know they f’ed up in the Gulf, but they’re still one of the most knowledgeable energy companies around).

Finally, I don’t endorse wikipedia much, but their section on peak oil is quite well-researched.

Thoughts on the BP Oil Spill

It goes without saying that the explosion of the Deepwater Horizon drilling rig and subsequent gushing of oil from the seafloor has saturated the news recently. Six weeks later, with no solution in place, many of us are feeling frustrated, even exasperated, at the lack of progress and at BP's inability to fix the mess it created. Tempers in the public, in the blogosphere, and within the Obama administration are flaring, with one question predominant: Why can't BP plug a damn hole on the bottom of the ocean?

It seems everyone wants to lend an opinion on the best way to fix the broken well (for an excellent list of the operations already attempted, go here). I've heard everything from dropping a giant sandbag on the wellhead to stuffing the bodies of BP CEO Tony Hayward and the totally-unconnected Dick Cheney into the well at ultra-high pressure.

Not a good time to be this man (Tony Hayward), but at least he's too skinny to realistically stop the flow of oil if his body were to be shoved into the well.

Unfortunately, in a bad little bit of public relations by BP, the American public has yet to grasp how excruciatingly difficult conducting operations on the seafloor are, especially when you are tied to a specific point (such as a gushing wellhead). I recently had the opportunity to conduct coring operations for my climate change research in 7000 feet of water (approximately two thousand feet deeper than the Deepwater Horizon's well) and figured I would share some of the lessons I learned from working in such deep water.

1. It takes quite a long time to get to the bottom of the ocean. Every single item that BP deploys to the ocean floor, whether it be a robot, containment dome, or massive saw, has to be lowered down with a winch (it is not simply left to fly with gravity!) The ship I worked on, the R/V Oceanus, had a trawl winch with 30,000 feet of high-tension steel cable, but was limited to lowering equipment at 150 feet per minute. While that's fast, you are still talking more than half an hour to get just a single piece of equipment to the seafloor at the depth of the Deepwater Horizon well. Every instrument swap or failure requires a half an hour to be raised to the surface, then another half an hour for a replacement to be lowered.

2. Lowering a piece of equipment to a precise spot on the ocean floor from a rocking boat and with ocean currents going every which way is not a simple procedure. This should be pretty obvious, but here's an example. Say your friend is lost in the woods and calls you with his exact location, asking to be picked up. How easy would it be to find him, even if you have an excellent GPS system? Oh yeah, and you're blindfolded, because you can't see anything in the ocean below 200 feet of depth. And you're stumbling around drunk, because ships rock on the ocean surface. I think you get my drift.

3. The pressure effect. Where we stand now, the pressure we face is a result of the weight of the overlying air, which adds up to 1 atmosphere. At 5000 feet depth in the ocean, the weight over the overlying water is about 150 atmospheres, or 150 times greater than at the surface of the earth.

This same analysis explains why the oil is currently flowing out at a (maximum) rate of 19,000 barrels per day, or 800,000 gallons per day (if that was all gasoline, that would be enough gas to drive a Toyota Prius, at 55 mpg, 44 million miles, or almost halfway to the sun. If you could drive in space and whatnot).

When the rig exploded, it was reportedly drilling 13,000 feet below the seafloor. To figure out what pressure this oil is under, we need to know the weight of the overlying rock and the water, which we know is 150 atmospheres. Rock is about 2.5 times denser than water, so it is about 2.5 times heavier; therefore, every foot of overlying rock increases the pressure of the oil 2.5 times more than a foot of water. So 13,000 feet of rock would add 1080 atmospheres of pressure. In other words, the oil that is currently gushing out from the Deepwater Horizon well is under 1230 atmospheres of pressure, or is pressurized over twelve hundred times greater than if at the surface of the earth.

This is why the well is gushing like a bunch of fire hoses, and why sealing it off is not a trivial operation. I'm not condoning BP's actions; they should have had a procedure in place, other than the blowout preventer, to avert such an ecological and economic disaster. But when they say that "this procedure has never been tried before at 5,000 feet", it is not a punch line. It is legitimately very difficult to deal with anything at 5,000 feet of depth, let alone a fluid gushing out at twelve hundred times surface pressure.

In short? Don't bother second guessing the BP scientists; there are very few people in the world who know the true difficulties of troubleshooting an accident under these trying conditions. But also don't expect much in the way of progress. Sadly, it looks like the Deepwater Horizon is going to keep on gushing until a relief well is finished drilling in August.

Maybe now we can reconsider what a ludicrous idea "drill, baby, drill" was. Such a careless attitude toward such a dangerous procedure can have devastating consequences. Unfortunately, we will be learning firsthand many of them in the coming months and years.

High Fructose Corn Syrup...no good.

America has serious weight problems. That is a given. But why??

An interesting study by the Princeton Neuroscience Institute demonstrated that, in rats fed equal amounts of calories in sugar water and in water with high-fructose corn syrup, the rats fed high-fructose corn syrup gained significantly more weight than rats fed with sugar, even though their caloric intake was exactly the same. In a parallel study, rats fed high-fructose corn syrup over a period of six months gained 48% more weight than rats on a normal diet, and showed classic symptoms of obesity.

Research Associate Nicole Avena, now of the University of Florida, remarked that "the excessive consumption of high-fructose corn syrup found in many beverages may be an important factor in the obesity epidemic [in humans]."

Yet studies in humans indicate that high-fructose corn syrup does not trigger different responses than normal table sugar. So is high-fructose corn syrup to blame for our country's weight issues?

I decided to crunch some data and see how the consumption of high-fructose corn syrup by Americans (available from the USDA, Table 52) and historical rates of obesity in the American population (from the CDC, Table 2) have changed. The results are probably not surprising:

Figure 1. Historical rates of adult obesity (BMI>30, %, blue) and extreme obesity (BMI>40, %, red) in 20-74 year olds in the United States, vs. per capita high-fructose corn syrup consumption (lb/year, green).

That's right, we Americans eat over 40 pounds of high-fructose corn syrup per year!!!

Then I wanted to see if there were any statistical relationships here (Remember, correlation does not imply causation):

Figure 2. Relationship between adult obesity (%) and per capita high-fructose corn syrup consumption (lb/year) from 1974 to 2006.

Interesting that a linear relationship between the obesity of the American population and corn-syrup consumption explains over 80% of the variance in the two factors. The relationship suggests that, between 1974 and 2006, a yearly increase in high-fructose corn syrup consumption of 1.8 pounds corresponded with a 1% increase in the obesity rate of the American adult population. If this relationship is projected forward, an increase in our current high-fructose corn syrup consumption by 4.5% will correspond to over 3 million more Americans becoming obese!!

Of course, as I said before correlation does not imply causation, so we cannot be certain that high-fructose corn syrup alone is driving American obesity levels (it likely is a plethora of factors). And this is by no means a complete dataset. Indeed, it appears from the last few years of data that high-fructose corn syrup consumption has leveled off, yet obesity rates continue to rise.

So what do we do about this public health problem? Perhaps reducing the egregious import tax on sugar and reducing subsidies for corn would aid in this sweetener transformation. In the meantime, I have actively tried to limit high-fructose corn syrup from my diet for the past several years, and I must admit I feel a heck of a lot better because of it.