Guatemala Sinkhole, 2010
Heavy rains from tropical storm Agatha likely triggered the collapse of a huge sinkhole in Guatemala on Sunday, seen above a few days afterward.
In the strictly geologic use of the word, a sinkhole happens when water erodes solid bedrock, carving an underground cavity that can then collapse. Many parts of the United States are at risk for that type of event.
The Guatemala sinkhole fits into a broader use of the term, which refers to any sudden slump of the ground's surface. Instead of solid bedrock, much of Guatemala City rests atop a layer of loose, gravelly volcanic pumice that is hundreds of feet thick. And at least one geologist says leaking pipes—not nature—created the recent sinkhole.
Overall, the risk for repeat sinkholes in Guatemala City is high—but highly unpredictable.
(See more pictures of the 2010 Guatemala sinkhole.)
Pictures: Guatemala Sinkhole Adds to World's Famous Pits
The sinkhole that opened up in Guatemala adds to the chasms—natural and human-induced—that have appeared from Alabama to Iceland.