Subsidence Has Many Causes

Comparing Apples and Oranges
Arthur Berman''s editorial in the October 2005 Bulletin is very informative and should help focus investigators research on subsidence in Houston, the Mississippi Delta, and surrounding areas of the Gulf Coast.  I''d like to make one observation based on Berman''s summary of findings by the various published investigators and govenment agencies.  Nowhere in the various quoted comments is it acknowledged that Houston''s geologic setting is very different from that of the lower Mississippi Delta.  Groundwater and hydrocarbon withdrawl having caused significant subsidence in the Houston area does not mean that they are the dominate factors in the delta.  Likewise, crustal downwarping as a result of the tremendous sediment column associated with the Mississippi should not be assumed to be the major culprit in Houston.  The various interested parties would do well to put asside their preconcieved ideas and work together to understand this serious issue and its various causes on a regional basis.