Earthquake Precautions and Judging Sources of Information
Not long ago, I came across a fairly detailed discussion of earthquake precautions, somewhere online; unfortunately I no longer remember where. The author appeared to be well informed, with extensive experience in dealing with disasters.
According to him, "take cover under a sturdy desk" is lethally mistaken advice. The sturdy desk, table, or whatever is likely to have its less solid parts crushed, and you, under it, will in turn be crushed by its more solid parts. Where you want to be is next to the sturdy desk or equivalent--ideally, I suppose, between two of them--so that you end up with at least one end of the chunk of the ceiling that fell on you held up by the solider part of the desk, and you under it and uncrushed. He had similar critiques, along essentially the same lines, for other parts of the standard advice.
I have no independent information on the author's expertise and do not even remember where I saw the information. Nonetheless, I am on the whole more inclined to believe him than to believe the sources of the advice reported in the BBC story. Why?
There are basically three ways of judging sources of information. One is internal evidence--does the author sound like a competent, well informed person who takes reasonable care to make sure that what he says is true? A second is external evidence about the information--does it fit other things I have reason to believe are true? A third is authority--do I have good reason to believe that the source of the information is reliable?
The earthquake advice I read passed the first test and, to the extent I could apply it, the second--it was at least consistent with the relevant geometry and physics, and what little I know of the construction of ceilings and the appearance of collapsed buildings. I had no easy way of verifying the author's claimed expertise, so could not apply the third.
The advice reported by the BBC, at least in the forms have seen it in the past, passes none of the tests. It is presented in a "this is official information, believe it" form, with none of the explanations and qualifications that signal a source taking care not to overstate its claims. It is routinely offered as advice to schoolchildren, presumably the ones most likely to have a convenient desk available to hide under--and my observation of school desks suggest that they are unlikely to have legs strong enough to bear the weight of a collapsed roof. The source is typically not a single, identifiable expert but the sort of bureaucratic organization that sets up an earthquake drill for five million people or generates civil defense instructions to be distributed to schoolteachers and read to children. My experience with the information produced by such organizations in other context is that it reflects less a concern with being right than a concern with not admitting to having been wrong.
Absent further information, I don't plan to hide under a desk if there is an earthquake--especially not under a classroom desk, if I happen to be in a classroom at the time. Are there any readers out there who can point me at better sources of information on the subject?
[Commenters pointed me at what is probably the piece I remember--on my son's blog. The ultimate source appears to be an article, "Triangle of Life," by Doug Copp. Snopes is critical of Copp. Looking at both of the pieces they link to (Red cross and Turkish) that critique Copp's arguments, I find their arguments rather less convincing than his; their strongest point is that building collapse is more likely in the third world disasters his arguments are largely based on than in a country like the U.S., where buildings are more solidly constructed, making optimal precautions different here.
I have not checked out the links Snopes provides to pieces that attack Copp rather than his arguments.]