David Wolman in Medium:
During the winter and early spring of 2009, Selvaggi and other seismologists at Italy’s National Institute of Geophysics and Volcanology had been monitoring numerous tremors around L’Aquila. The sequence of small quakes over a short period of time, known as a “seismic swarm,” is distinct from the aftershocks that follow a big quake.
And in places like L’Aquila, they are not necessarily abnormal. Local media repeatedly relayed that generic message to the public. Regional government officials insisted there was no need to fret, despite chronically unenforced building codes. The Civil Protection Department for Abruzzo, the region where L’Aquila is located, even issued a press release flatly proclaiming there would be no big earthquake.
But the people of L’Aquila were understandably concerned. Over the centuries, the city had been devastated by several major quakes: One in 1703 killed 10,000 people, and a magnitude 7.0 quake in 1915 killed 30,000. This history has given rise to a culture of caution. When the ground seems especially temperamental, many residents — like their parents and grandparents before them — grab blankets and cigarettes and head outside to mill about in a piazza or a nearby park. Others sleep in their cars. Better not to be in an ancient building that hasn’t been seismically reinforced.