Geonews Clips – April 28, 2008

• The argon-argon age analysis method is used to determine the age of rocks over a wide time span. However, Paul Renne, director of the Berkeley Geochronology Center and an adjunct professor of earth and planetary science at UC Berkeley, has contended that this method had systematic errors that resulted in uncertainties of about 2.5 percent in age analyses. Recent refinements to this technique have greatly improved precision in age analyses.

• The National Seismic Hazard Maps just published by the U.S. Geological Survey provides assessment of earthquake hazards estimation for the United States.

• Carbon dioxide levels were well regulated for hundreds of thousands of years by the Earth's natural feedback mechanism say scientists in the journal Nature Geoscience. They also state that human activity is now the cause for elevated CO2 emissions such that the planet's natural balancing mechanism cannot keep up.
  
  Go to www.earthmaps.com/geology_news.htm for links to these topics.