Scientists in the United States have developed a method that may help to predict earthquakes earlier. They say it could give people who live in deadly earthquake areas enough warning to leave before an earthquake hits.
Currently, the most modem systems for predicting earthquakes find them only a short time before the event. Like most strong earthquakes , the one that hit Southwestern China in May was not identified early enough for people to flee the area. That earthquake killed more than 69,000 people, which rated eight point zero in intensity.
But scientists who study earthquakes are reporting that new technology could measure very small changes in the Earth's surface. Their report was published this month in Nature magazine.
Fenglin Niu is a seismologist in Rice University in Houston, Texas. He and his team performed experiments along California's San Andreas Fault, an area famous for its many earthquakes. The team placed highly sensitive electrical devices about one kilometer below ground in two different places. The devices were able to measure even small changes in air pressure on the Earth's surface. The scientist says such changes are caused when rocks push together, forcing air out of small cracks in the rock. When this happens, seismic waves travel faster than usual through the rock.
The experiment was performed near Parkfield,California. Two earthquakes hit the area in late 2005. The first took place on December 25. A smaller earthquake struck five days later. The scientists noted changes in the Earth's surface about ten hours before the first earthquake struck. That earthquake rated three in intensity. They then found similar changes taking place two hours before the other earthquake struck five days later.
If additional tests confirm the changes are linked to earthquakes ,the scientists believe that their equipment could be used for early warning systems. A system that provides a warning signal ten hours before a major earthquake could help move people from the area and save lives.
The scientists now hope they can find earthquakes with even greater intensity by placing their equipment deeper in the ground.
What is the best title for the passage?
A.A new way to help predict earthquakes |
B.The earthquake in Southwestern China |
C.A better understanding of earthquakes |
D.Early warning systems of earthquakes |
If the new way works, ______ .
A.fewer earthquakes will break out |
B.rescue workers can save more buried people in ruins |
C.a warning can be given at least ten days before the major earthquake |
D.fewer people will be killed in an earthquake |
The devices can predict the earthquake by ______ .
A.reaching the center of the earthquake |
B.detecting the temperature changes in the Earth's crust |
C.measuring changes in air pressure on the Earth's surface |
D.recording sound waves under the ground |
We can infer that ______ .
A.the equipment is perfect enough to be used in practice |
B.it is unknown if greater earthquakes can be predicted by the equipment |
C.the deeper the equipment is placed, the less accurate the measurement is |
D.the equipment has helped save many lives in the earthquake in Sichuan in May |