In the latest event, two quakes hit on Friday at around 11:30 a.m. and shortly after noon (local time) along the borders of Guizhou and Yunnan provinces, a mining and agricultural region home to some of the nation’s poorest people.
Though of moderate strength, the quakes were shallow, which media reports suggest often cause more damage.
The worst-hit area was Yiliang County, where all but one of the deaths occurred. Media reports have suggested that dodgy building construction contributed to the relatively high death toll in that county, along with the area’s high population density and landslide-prone hillsides.
Damaged roads made it difficult for rescuers to reach some outlying regions and towns, while mobile phone services were down and regular phone lines disrupted.
Though quakes occur frequently, houses and buildings in rural China are often constructed poorly. In 2008, for example, badly-built structures were blamed for a significant portion of the almost 90,000 which occurred during a horrific magnitude 7.9 quake that hit Sichuan province.
The death toll from the latest quake contrasts with that of a 7.6 magnitude quake that struck Costa Rica last week in which only two people died and damage was kept to a minimum through a combination of the depth of the quake (41 kilometres below the surface) and well-constructed buildings.