Over 3 km-long crack opens up in Arizona

A gaping 3.2 kilometre long crack has opened up in the barren land of Arizona, possibly due to the withdrawal of groundwater for agricultural activities, say scientists who have warned that the fissure is likely continue growing.
A footage from an Arizona Geological Survey (AZGS) in the US drone showed the extent of the huge fissure splitting the barren land.
The crack is so big that it dwarfs people walking along its edges in the video.
The northern part of the fissure, which is older and partially filled in, is shallow, while the southern portion is tens of feet deep in some spots, according to Joseph Cook, a geologist with the AZGS.

"Some areas are about three metres across and up to 7.5 to nine metres deep, while others are a narrow surface crack less than an inch across," Cook said.
"These narrow sections sometimes have open voids underground, so collapse of the overlying material is possible - this is how the deep open portions of the fissure formed," he said.

Cook first spotted the crack in Google Earth imagery from December 2014. After mapping the fissure using GPS, the researchers got another look using a drone, 'Live Science' reported.
Water withdrawal, primarily for agriculture, is the culprit, Cook said. As groundwater is pulled up, it leaves a void and the land above it subsides, leading to cracks.

Researchers have set up 26 study areas where they have mapped a total of 275 kilometres of these earth fissures.
Not only does Cook expect the crack to lengthen, but the opening beneath the surface is likely bigger than what can be seen.