BOONEDr. Roland Gehrels will present a lecture on "Sea-Level Change and Global Warming" Oct. 16 at 4 p.m. in Rankin Science West 023 at Appalachian State University.
Gehrels is a professor of geology at the University of Plymouth, Plymouth, Devon, England. His talk is sponsored by the Department of Geology at Appalachian. Gehrels studies the different species of foram tiny single-celled organisms that construct shells preserved in peat dug from salt marshes to track changes in sea level. He has found that sea levels in parts of Nova Scotia in Canada have risen by almost two feet in the last 250 years. "Sea level today is rising faster than at any time in the past when it was subject to natural climate change," he says. Gehrels has compared his foram study of the past 100 years with tide-gauge records in Nova Scotia, which document sea-level change as measured from a harbor pier. Because the records match, he is confident in the accuracy of the data from the foram research. "Along the coast of Maine, these records are available for the period since 1912," Gehrels said in a 2004 report in the Geological Society of America's Science Blog. "My records are geological reconstructions from salt marsh sediments. They go further back in time than the instrumental observations. The most recent part of my reconstruction, the part that covers the 20th century and thus overlaps with the instrumental record, gives the same values as the tide-gauge record. This is important because it is a check on the validity of the reconstruction. If they didn't match, it would tell you something is wrong with the reconstruction." Gehrels told Science Blog that there had been two instances of a rise in sea level. "First, sea level rose at the end of the 18th century as a result of natural climatic warming. In the 19th century, sea level didn't rise much at all. But at the beginning of the 20th century, sea level took off again, in tandem with global and hemispheric temperature rise," he said. "But sea level is rising faster now than during times when there was only `natural' warming. This is a strong indication that current sea-level rise is not just the result of `natural' warming but is, at least in part, caused by human-induced climate change." To subscribe, send a message to: [EMAIL PROTECTED] Or go to: http://groups.yahoo.com/group/FairfieldLife/ and click 'Join This Group!' Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/FairfieldLife/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/FairfieldLife/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
