Moon's pull triggers earthly tremors

Seismic sensors show the moon's tug on Earth not only causes ocean tides but also tremors triggered by the rising and falling seas, U.S. researchers said.

Moon's pull triggers earthly tremors

Data from the detection equipment set up on Washington's Olympic Peninsula and British Columbia's Vancouver Island Ocean showed ocean tides exert pressure that produces periodic seismic activity deep underground along the northwest coast off North America, the San Francisco Chronicle reported.

Earth's tides are caused by the moon's gravitational pull.

University of Washington researcher Justin Rubenstein, head of the team of Seattle scientists whose documentation of the previously unknown effect appears on the online version of the journal Science Express, said they still are at a loss to explain how or why the phenomenon occurs. The tremors aren't noticeable on the surface, the scientists said.

William Ellsworth of the U.S. Geological Survey said the researchers' work "is an exciting and extremely important development.

"The discovery gives us a new window into parts of the Earth that we haven't seen before, and into events that occur at the deep roots of earthquake faults," said Ellsworth, who wasn't involved in the project. "Now we are all thinking about their possible causes."


Güncelleme Tarihi: 25 Kasım 2007, 15:10