Mea Culpa: through an ash cloud, darkly

Questions of language and style in last week’s Independent, arbitrated by John Rentoul

Mount Semeru sends clouds of ash a long way into the air (EPA)

It is hard to work out exactly how this could have happened, but we ended up with a remarkable case of spurious precision in a report of the eruption of a volcano in Indonesia. “The eruption led to thick columns of ash spread over 49,212ft (15km) into the sky, according to Japan’s Meteorology Agency,” we wrote. Thanks to Roger Thetford and Richard Thomas for drawing my attention to this sentence.

First, the ash was not “spread over” a distance. If we were reporting how far it spread, we would have used a unit of area, such as a square mile. What we were reporting was that the ash shot upwards, in approximately a straight line, into the sky. Fifteen kilometres is a long way, and it doesn’t really need to be converted into other units for the reader to understand that. Yet we gave the distance first in feet, and to five significant digits. The ash went up not 49,211 feet, or 49,213, but 49,212.

Some of what happened here is discernible through the cloud of debris. The Japanese Meteorology Agency does indeed use feet, which is conventional in the fields of weather, atmosphere and air travel. Only it uses feet in round thousands or, mostly, tens of thousands. What the agency actually said was that the plume of ash reached a height of 50,000ft.