sinkholes in Wink, Texas
© Google Maps The Wink sinkholes are about one mile apart.
Just days after a massive sinkhole opened up in the Ottawa downtown core, scientists are now warning that two giant and rapidly expanding sinkholes in Texas are at risk of collapsing into each other.

They are about 2 km apart and sit between the cities of Wink and Kermit in the West Texas oil patch. A population of nearly 7,000 people live in the area.

Satellite radar imagery shows the sinkholes are growing and new ones are forming at an "alarming rate" as nearby subsidence occurs, according to a study recently published in the scientific journal Remote Sensing.

Geophysicists at Southern Methodist University (SMU) in Dallas, Texas say the area surrounding the two massive sinkholes is unstable, which could lead to the development of one giant sinkhole.

"This area is heavily populated with oil and gas production equipment and installations, hazardous liquid pipelines, as well as two communities. The intrusion of freshwater to underground can dissolve the interbedded salt layers and accelerate the sinkhole collapse," said Jim-Woo Kim, who leads the SMU geophysical team reporting the findings. "A collapse could be catastrophic. Following our study, we are collecting more high-resolution satellite data over the sinkholes and neighboring regions to monitor further development and collapse."

Wink sinkholes in Texas
The sinkholes were originally caused by the area's prolific oil and gas extractions, which peaked from the mid-1920s to the mid-1960s.

Scientists say the first hole, dubbed Wink Sink No.1, opened up in 1980 near the Hendricks oil well. While it is the smallest of the two sinkholes at 110 metres wide, it appears to be the most unstable. Wink Sink No. 2 opened up 22 years later in 2002 and currently varies from about 200 to 270 metres across.

The holes continue to grow due to changing groundwater levels and dissolving minerals beneath the Earth's surface.

Meanwhile, the greatest rate of ground subsidence is not at either sinkhole, but at an area northeast of No.2 where the ground has been eroding at an annual rate of over 13 centimetres for the last eight years.

"Sinkhole formation has previously been unpredictable, but satellite remote sensing provides a great means to detect the expansion of the current sinkholes and possible development of new sinkholes," said Kim. "Monitoring the sinkholes and modeling the rate of change can help predict potential sinkhole development."

Source: SMU