Small aftershocks occur with a greater frequency than large ones; however, aftershock frequency falls off with the passage of time.
Survey officials reported two small aftershocks, of magnitude 2.8 and 2.2, within 90 minutes of the original jolt.
With small aftershocks continuing to shake Padang on Thursday, residents sat in streets and on curbs, listening to small radios as the city's mayor gave live updates.
But it is wonderful to find premonitions of them and small aftershocks, and their contexts can now be imagined much more clearly.
My colleague Henry Fountain adds: The geological survey reported two small aftershocks, of magnitude 2.8 and 2.2, within 90 minutes of the earthquake, which occurred at 1 51 p.m. Meredith Nettles, a seismologist at Lamont-Doherty, said that such smaller aftershocks, up to magnitude 4 to 5, would be expected following the quake.
Small aftershocks from the Eliot wars bob up here, as when the lower-case "jew" and "jews" of "Gerontion" and "Burbank with a Baedeker: Bleistein with a Cigar" are awarded a face-saving majuscule, though the lower-case "jew" of "Dirge" remains ("Graves' disease in a dead jew's eyes!").
Numerous small aftershocks were also reported on Sunday.
The amplitude was magnified to see the small aftershocks.
A relatively shallow alluvial station, HASTAHANE, experienced considerable amplification for small aftershocks and deamplification for the strongest aftershock in frequencies between 0.5 and 2 Hz.
However, in the case of short-term missing of small aftershocks, the variation of detection is usually unknown.
