Editor, Gazette-Journal:

In his Nov. 17 article "Study addresses concerns about saltwater intrusion in region," Bill Nachman presents his "cherry picked" portions of a four-page report from the Virginia Institute of Marine Science. His readers would benefit from knowing that not all "sea level rise" is the same.

There is global sea level rise, and is measured by tidal gauges and more recently by satellites. The numerical values depend where, and over what period of time the measurements are taken. Portions of the oceans can be rising as other portions are falling. The most recent data quoted are for a global average rise of about seven inches over the past 100 years, and a deceleration in the rate of rise.

Local sea level rise is the relative rise measured in a particular region, once such factors as land mass rebound and subsidence are factored in. Chesapeake Bay is an active geological region reflecting the original meteor impact and ice coverage...