July 2016 – TEXAS – Satellite
radar images reveal ground movement of infamous sinkholes near Wink,
Texas; suggest the two existing holes are expanding, and new ones are
forming as nearby subsidence occurs at an alarming rate. Residents of
Wink and neighboring Kermit have grown accustomed to the two giant
sinkholes that sit between their small West Texas towns. But now radar
images taken of the sinkholes by an orbiting space satellite reveal big
changes may be on the horizon.
A new study by geophysicists at
Southern Methodist University, Dallas, finds the massive sinkholes are
unstable, with the ground around them subsiding, suggesting the holes
could pose a bigger hazard sometime in the future. The two
sinkholes—about a mile apart—appear to be expanding. Additionally, areas
around the existing sinkholes are unstable, with large areas of
subsidence detected via satellite radar remote sensing.
That leaves the possibility that new
sinkholes, or one giant sinkhole, may form, said geophysicists and study
co-authors Zhong Lu, professor, Shuler-Foscue Chair, and Jin-Woo Kim
research scientist, in the Roy M. Huffington Department of Earth
Sciences at SMU. “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 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.”
Lu and Kim reported the findings in the
scientific journal Remote Sensing, in the article “Ongoing deformation
of sinkholes in Wink, Texas, observed by time-series Sentinel-1A SAR
Interferometry.” The research was supported by the U.S. Geological
Survey Land Remote Sensing Program, the NASA Earth Surface &
Interior Program, and the Shuler-Foscue Endowment at Southern Methodist
University. The sinkholes were originally caused by the area’s prolific
oil and gas extraction, which peaked from 1926 to 1964. Wink Sink No. 1,
near the Hendricks oil well 10-A, opened in 1980. Wink Sink No. 2, near
Gulf WS-8 supply well, opened 22 years later in 2002.
It appears the area’s unstable ground
now is linked to changing groundwater levels and dissolving minerals,
say the scientists. A deep-seated salt bed underlies the area, part of
the massive oil-rich Permian Basin of West Texas and southeastern New
Mexico. With the new data, the SMU geophysicists found a high
correlation between groundwater level in the underlying Ogallala Aquifer
and further sinking of the surface area during the summer months,
influenced by successive roof failures in underlying cavities.
Satellite images and groundwater
records indicate that when groundwater levels rise, the ground lifts.
But the presence of that same groundwater then speeds the dissolving of
the underground salt, which then causes the ground surface to subside. –Physics
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