The water level of Texas' Edwards Aquifer was displaced about a foot Friday after energy released from a massive earthquake near Japan put the squeeze on the underground rock formation that supplies drinking water for much of Central Texas.
The 9.0-magnitude quake caused its walls to contract and expand, officials with the Edwards Aquifer Authority said Wednesday. A monitor in a Bexar County well that continuously records the aquifer's water level noted the oscillations, which lasted about two hours from late Thursday to early Friday morning, said Geary Schindel , the authority's chief technical officer. The force from the quake took about 15 minutes to reach the aquifer, he said. "When a wave from an earthquake passes, it slightly compresses and dilates the aquifer, and the water will shoot up and down," Schindel said. "Any time we see a major earthquake, it's commonly recorded in that well. They act as seismographs." The oscillations during high-energy earthquakes are common in artesian aquifers, or confined aquifers, where the water is pressurized, including the Edwards Aquifer, Schindel said. "We saw Haiti, we saw Sumatra, Japan, a couple in Mexico and Alaska," he said of recent earthquakes. The well, named J-17 , has been monitoring the aquifer's water level in Bexar County since the 1950s, Schindel said. A float that rests on the water surface hundreds of feet underground is connected to a wire and a wheel that records the level on pen and paper, he said. Water restrictions are tied to readings, Schindel said. The sprawling aquifer cuts underground through Central Texas and provides drinking water for about 1.7 million people, including most of San Antonio, said Roland Ruiz, spokesman for the regulatory agency that manages and protects the aquifer's San Antonio segment. ddoolit...@statesman.com; 445-3671 http://www.statesman.com/news/local/japan-earthquake-displaced-water-in-edwards-aquifer-1326387.html --------------------------------------------------------------------- Visit our website: http://texascavers.com To unsubscribe, e-mail: texascavers-unsubscr...@texascavers.com For additional commands, e-mail: texascavers-h...@texascavers.com
