Changes in the earth's chemistry could help scientists predict earthquakes, according to researchers in Sweden. The method involves determining the concentration of iron, chromium, manganese, zinc, and copper. Alasdair Skelton of Stockholm University and his colleagues found a correlation between the levels of these metals in groundwater at a depth of 1.5 km before and after a major earthquake (5.8 on the Richter scale) that occurred in northern Iceland in September 2002. They monitored the concentrations ten weeks before and for one year after the earthquake and spotted chemical peaks at 10, 5, 2, and 1 week before the earthquake. The concentrations returned to normal levels after the earthquake. The researchers suggest that the dissolved metals migrate upwards from deeper in the earth entering the groundwater at about 1.5 km as the permeability of the earth's crust changes when an earthquake is imminent. Skelton suggests that the findings must now be confirmed for other earthquake prone regions of the world.
Heavy metals signal quake