Scientists say water samples
give ample quake warning

Swedish geologists say their
work in Iceland may also apply
to Hawaii and Japan

STOCKHOLM, Sweden >> Swedish geologists may have found a way to predict earthquakes weeks before they happen by monitoring the amount of metals like zinc and copper in subsoil water near earthquake sites, scientists said yesterday.

The technique could apply to other regions containing basalt rock such as Hawaii and Japan, they said.

Predicting earthquakes has been a notoriously tricky business -- accurate warnings can usually only come seconds before a quake -- and the Swedish scientists are touting their findings as a breakthrough that could save lives.

"Everyone knows that a big quake will hit San Francisco sometime," said Lillemor Claesson, a doctorate student at Stockholm University who was part of the research team.

"But if the prediction is within a few seconds, no one has time to react," she said in a phone interview from Iceland, where she is conducting fieldwork. "So this is a very good time frame."

The findings were presented in the latest issue of Geology, a journal published by the Geological Society of America.

In one case detailed by the scientists, water samples taken 4,900 feet beneath the surface in northern Iceland show the content of several metals increased dramatically a few weeks before a magnitude-5.8 earthquake struck.

Afterward, the amount of the metals in the water returned to normal levels.

"This could save lives," Claesson said. But before the method can be proved, similar tests have to be done prior to other earthquakes, said Alasdair Skelton, a geologist at Stockholm University who came up with the idea for the study.

Claesson said bedrock near earthquake sites is usually full of cracks that contain water. Before earthquakes, the bedrock heats up, releasing the metals into the water.

In the water samples taken in Iceland, the levels of manganese, zinc and copper all increased by up to 1,000 percent before quakes.

The bedrock at the test site is basalt, which is also found in other earthquake-prone areas like Hawaii and Japan. That means the same tests could be used in those places, she said. Tests in areas with a different type of bedrock would have to be modified depending on which metals are common.

Claesson said she and other scientists will try to simulate an earthquake in a lab, to test its effects on the water in basalt.