Boston Marathon Bombings

April 16, 2013

I’m sure that I’m like most other Americans in reacting with a mixture of sorrow, disgust, and anger to the horrible bomb attacks in Boston yesterday.   Of course, we all extend our sympathies, thoughts, and prayers to the victims and their families, too.  The story of what happened is still unfolding: physical and other evidence is still being analyzed, and no one, so far, has claimed responsibility for this crime.  I think it is not only foolish, but also counter-productive, to jump to conclusions based on incomplete facts or speculation.  I expect this will be the first in a number of posts on this incident.

I was able to keep current with the press coverage of the story through most of yesterday afternoon.  (The incident probably struck home for me a bit more than average, since I lived in Boston for about ten years, within a few blocks of Copley Square, and worked nearby as well.)  When the prospect of an inch or two of snow gets reporters hyper-ventilating, I guess it is not too surprising that this incident really got them going.  It was clear that someone in the newsroom was trying to rein in the more extreme speculation, but some fairly obvious products of someone’s imagination made it through anyway.

One early report showed a very jerky video of one of the explosions (it later became clear it was the first), with breathless commentary about “an enormous bomb”.  Now, “enormous” is one of those words that, to paraphrase Mark Twain, allows a considerable return in speculation for a trifling investment of fact.  I am certainly not an explosives expert, but I have seen the immediate aftermath of a couple of large explosions in similar environments.  For example, I was perhaps half a mile away in the City of London when the Provisional IRA detonated a bomb at the Baltic Exchange in St Mary Axe on April 10, 1992.  That was a large bomb,  estimated to contain 45 kg (100 lb.) of Semtex, plus about a ton of fertilizer based explosive.  I have never seen so much broken glass in my life; it was impossible to walk without stepping on it.

In that early video, there was no noticeable glass on the pavement, and there were a couple of large plate glass windows visible, intact, within a few yards of the explosion site.  I remarked at the time that the bomb, if that’s what it was, could not have been very big — probably something in a backpack or briefcase.  (I do have a little background knowledge on this point.  As part of my job, I had some security responsibilities for our operations in the City, and got periodic briefings from the security services.)  That the devices were small, perhaps 2-3 pounds of explosive, seems to be the current consensus from authorities today.

The Associated Press [AP] initially made a rather strange report yesterday afternoon, saying that cellular telephone service was being shut down.

A law enforcement official, citing an intelligence briefing, said cellphone service had been shut down Monday in the Boston area to prevent any potential remote detonations of explosives.

The TV reporter presenting this suggested that this was being done to prevent further bombs from being detonated by cellphones, and that, for the same reason, people should not use their landline phones, either.  Now this last bit is just complete nonsense; my avoiding use of my phone does not prevent a Bad Guy from using his; in fact, if anything, his call will be completed more expeditiously.  AP later retracted the story, having checked with the cellular carriers.  I suspect the original story was based on a garbled request to avoid unnecessary phone usage; it is almost a given that networks will be stressed by heavy usage following any sort of man-made or natural disaster.

I know that the media have a difficult job, and that trying to piece together a narrative from fragments of information is especially tricky.  I’d hope, though, that everyone, reporters and audience alike, would try to maintain a rational view of the situation, and not let their emotions run amok.  Terrorism is, after all, a tactic that is intended to produce fear, fear out of proportion to the actual damage done.  As I’ve written before, we need to take care not to let terrorists win “on the cheap”.

Over at The Atlantic‘s site, Bruce Schneier has a revised version of an earlier essay, focusing on this same point.

As the details about the bombings in Boston unfold, it’d be easy to be scared. It’d be easy to feel powerless and demand that our elected leaders do something — anything — to keep us safe.

It’d be easy, but it’d be wrong.  We need to be angry and empathize with the victims without being scared.

He also has an interview with Ezra Klein of The Washington Post on the paper’s “WonkBlog”.

Contrary to what our instincts and emotions may be screaming, terrorism is a rare event, and mounting a successful terrorist attack is not easy.  Evil geniuses, like Professor Moriarty or the Joker, are denizens of fiction, not reality.  And, no matter how draconian our security response is, there is no way to guarantee perfect safety.  We need to remain as level-headed as we can.

Refuse to be terrorized.

Subterranean Rumblings

April 7, 2013

Especially in the winter months, first time visitors to New York City are often bemused by the sight of plumes of steam rising from manholes in the street (sometimes surmounted by jolly red-and-white “smokestacks”).  Where do they come from?  Are they byproducts of some subterranean “dark satanic mills”, or perhaps a covert entrance to Saruman’s workshops at Isengard?   Actually, they come from the Con Edison steam distribution system,which distributes steam from seven generating plants through underground pipes to most of Manhattan south of about 90th Street.  [Coverage map PDF]  The steam is used to provide heat, hot water, and other services; it serves around 100,000 commercial and residential establishments with more than 13.5 million tons of steam every year.  Since about 50% of the steam is produced as a by-product of electricity generation, the system as a whole is more efficient than individual building heating and hot water plants.  The system, the first parts of which went into service in 1882, works fairly well, though there have been some spectacular failures in the aging infrastructure, notably the 2007 explosion at 41st Street and Lexington Avenue, which left a crater in the street 35 feet wide and 15 feet deep.

Here in Washington DC, we have our own peculiar sub-surface activity: our manholes do not spout steam, but do occasionally explode.  Natural gas has been suspected as a cause of these explosions, but hard evidence for this has been scarce.  Now, the ScienceNOW news service of the AAAS reports that researchers have found high methane concentrations in the city, and very high concentrations in manholes.

Researchers who mapped methane concentrations on the streets of the nation’s capital found natural gas leaks everywhere, at concentrations of up to 50 times the normal background levels, they reported here last week at a meeting of the American Physical Society. The leaking gas wastes resources, enhances ozone production, and exacerbates global warming—not to mention powering the city’s infamous exploding manholes.

Methane [CH4] can come from a variety of sources, including landfills, swamps, cattle flatulence, and oil/gas production.  It is also the principal constituent of natural gas.  It is potentially an important source of global warming, since it is more than 20 times more potent as a greenhouse gas than carbon dioxide [CO2], the usual suspect.  The research team, headed by Robert Jackson of Duke University, suspected that natural gas leaks might be contributing to increased methane concentrations in the atmosphere; the results confirmed their suspicions:

… they drove along every street in the District of Columbia and regularly sampled the air, mapping the concentration of methane over a period of 2 months. They found thousands of places with air concentrations significantly above the 2 parts per million background level typically found in cities, with some areas as high as 100 ppm.

Methane itself is non-toxic and odorless (the gas company adds a chemical, typically a thiol like tert-butyl mercaptan, to make the gas stink); however, methane can promote the formation of ozone, which is a respiratory irritant.

The research team got more striking results when they sampled methane concentration in manholes.  In some locations, they detected methane concentrations of 100,000 ppm (or 10%).  My well-worn Handbook of Chemistry and Physics gives (approximate) explosive limits for methane / air mixtures at 5% and 15%, so the detected values are well within the danger zone.  The team suspects corroding iron gas distribution mains as the source of the leaks.  There are an average of 38 “manhole incidents” per year in Washington, so something is clearly amiss. (The same researchers have some similar data from Boston.)

It is of course sort of interesting to discover what may be causing incidents like exploding steam pipes or manholes, but these incidents reflect a larger issue.  There is a great deal of very old infrastructure in the US. much of which has not received very much in the way of maintenance.  (As another, unrelated, example, in August 2007, a highway bridge carrying Interstate 35-W across the Mississippi River in Minneapolis collapsed.)  For years, the American Society of Civil Engineers, has issued an annual report card on the parlous state of the nation’s infrastructure; it does not make for encouraging reading.

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