groundwater removal by over pumping added enough stress to a fault in spain to cause a deadly earthquake
Groundwater removal triggered the unusually shallow and deadly earthquake that hit Lorca, Spain, in 2011, according to a new study.
Scientists have known for decades that pumping water into the Earth can set off small earthquakes. But this is the first time that removing water has been identified as an earthquake trigger, researchers said. Both the size and the location of the quake were influenced by groundwater pumping, the study found.
"The fact that the very tiny stress changes due to normal processes, such as the extraction of groundwater, could have an effect on very large systems such as faults, that's very surprising," said Pablo González, lead study author and a postdoctoral scholar at the University of Western Ontario in Canada.
The researchers were also able to precisely calculate the physical changes that generated the quake. The results will help seismologists better understand the physics that control when an earthquake starts and stops — an important step in predicting when and where a quake will occur, and its size.
"We need observations of this sort to calibrate physical models" of faults, said Jean-Philippe Avouac, a geologist at Caltech in Pasadena, Calif., who was not involved in the study. "The initiation and arrest of [fault] ruptures are something we are trying to constrain," he told OurAmazingPlanet.
Small quake, devastating effect
The May 5, 2011, earthquake was a relatively moderate magnitude 5.1. Quakes of this size usually don't cause significant damage in developed countries. A 2006 earthquake of magnitude 4.8 near Lorca did not cause any deaths. [Video: What Does Earthquake 'Magnitude' Mean?]
But the 2011 quake ruptured only 0.6 miles (1 kilometer) below the Earth's surface, which meant the earthquake's energy was concentrated at the surface. Nine people were killed and dozens were injured, and both unreinforced masonry, like medieval churches, and modern buildings were damaged.
http://news.yahoo.com/deadly-spain-...RhaWQDBHBzdGNhdANob21lBHB0A3NlY3Rpb25z;_ylv=3
Groundwater removal triggered the unusually shallow and deadly earthquake that hit Lorca, Spain, in 2011, according to a new study.
Scientists have known for decades that pumping water into the Earth can set off small earthquakes. But this is the first time that removing water has been identified as an earthquake trigger, researchers said. Both the size and the location of the quake were influenced by groundwater pumping, the study found.
"The fact that the very tiny stress changes due to normal processes, such as the extraction of groundwater, could have an effect on very large systems such as faults, that's very surprising," said Pablo González, lead study author and a postdoctoral scholar at the University of Western Ontario in Canada.
The researchers were also able to precisely calculate the physical changes that generated the quake. The results will help seismologists better understand the physics that control when an earthquake starts and stops — an important step in predicting when and where a quake will occur, and its size.
"We need observations of this sort to calibrate physical models" of faults, said Jean-Philippe Avouac, a geologist at Caltech in Pasadena, Calif., who was not involved in the study. "The initiation and arrest of [fault] ruptures are something we are trying to constrain," he told OurAmazingPlanet.
Small quake, devastating effect
The May 5, 2011, earthquake was a relatively moderate magnitude 5.1. Quakes of this size usually don't cause significant damage in developed countries. A 2006 earthquake of magnitude 4.8 near Lorca did not cause any deaths. [Video: What Does Earthquake 'Magnitude' Mean?]
But the 2011 quake ruptured only 0.6 miles (1 kilometer) below the Earth's surface, which meant the earthquake's energy was concentrated at the surface. Nine people were killed and dozens were injured, and both unreinforced masonry, like medieval churches, and modern buildings were damaged.
http://news.yahoo.com/deadly-spain-...RhaWQDBHBzdGNhdANob21lBHB0A3NlY3Rpb25z;_ylv=3
