危地马拉为什么总出现“天坑”？（双语）

 

    地质专家表示，危地马拉城街道上出现的天坑可能不是自然因素造成的，而是人为活动的结果。 Human activity, not nature, was the likely cause of the gaping sinkhole that opened up in the streets of Guatemala City, a geologist says.

    美国新罕布什尔州达特茅斯学院地质学家萨姆•博尼斯称，可能是由于地下管道爆裂或雨水排放下水管道渗水，在地下掏出一个洞穴，最终导致这个塌陷洞形成。 A burst sewer pipe or storm drain probably hollowed out the underground cavity that allowed the chasm to form, according to Sam Bonis, a geologist at Dartmouth College in New Hampshire.

    据估计，危地马拉城天坑宽60英尺(18米)，深300英尺(100米)，看起来是受到热带风暴“阿加莎”强降水的影响而形成的。 The Guatemala City sinkhole, estimated to be 60 feet (18 meters) wide and 300 feet (100 meters) deep, appears to have been triggered by the deluge from tropical storm Agatha.

    不过地洞形成的首要原因是与该城和它的地下排水设施所在的位置有关，其地表以下深达数百米的地层主要是由之前火山爆发产生的浮石填充物构成。 But the cavity formed in the first place because the city—and its underground infrastructure—were built in a region where the first few hundred meters of ground are mostly made up of a material called pumice fill, deposited during past volcanic eruptions.

    博尼斯说：“许多情况下，火山浮石大多是由(像沙砾一样松散的)流动性粒子形成的，它们在高温和重压下结合在一起，变成固体岩石。” "Lots of times, volcanic pumice originates as a flow [of loose, gravel-like particles], and because of the heat and the weight, it becomes welded into solid rock," Bonis said.

    他提到：“危地马拉城的(浮石)非常松散，至今仍未形成坚硬的岩石，因此很容易被侵蚀，尤其易受快速流动的水体影响。” "In Guatemala City [the pumice is] unconsolidated, it's loose," he said. "It hasn't been hardened into a rock yet, so it's easily eroded, especially by swift running water."

    总的来说，危地马拉城的地区规划条例和建筑法规非常薄弱，为数不多的几项规章制度也常常被忽视。也就是说泄漏的下水管道长期得不到维护，为这种天坑的形成创造了先决条件。