Research Interests

  • Seismology, especially seismic structure of the seafloor
  • Scholte waves
  • Seafloor instrument development, especially of Ocean-Bottom Seismometers (OBSs) and seismic sources
  • Current: Seafloor seismic noise and its propagation through seafloor sediments


  • B.S., Georgia Institute of Technology
  • M.S., University of Wisconsin-Madison
  • Ph.D., University of Wisconsin-Madison
Principal Works:
In the three publications:

Dorman, LM, Lewis BTR.  1970.  Experimental Isostasy .1. Theory of Determination of

the Earths Isostatic Response to a Concentrated Load.
Journal of Geophysical Research. 75:3357.  
Lewis, BTR, Dorman LM.  1970.  Experimental Isostasy .2. An Isostatic Model for USA
Derived from Gravity and Topographic Data. Journal of Geophysical Research. 75:3367.
Dorman, LM, Lewis BTR.  1972.  Experimental Isostasy .3. Inversion of Isostatic Green-Function and
Lateral Density Changes. Journal of Geophysical Research. 77:3068   

Brian and I showed that the relationship between the earth's

topography and its gravity field could be represented as a
Fredholm integral equation of the first kind*.
Moreover, the kernel of this equation could be
extracted from gravity and topographic data.  And, that this
kernel, could be transformed into a function of depth for the
case of 'local compensation', which represents an earth
whose lithosphere can support topography only 'locally'.
This is called the Pratt model, after John Henry
The transformation from the kernel, or Greens Function, into the variation of
density with depth is through application of an inverse Laplace Transform, which
is a process which amplifies high spatial frequencies, and requires regularization,
such as use of the method of Backus and Gilbert.
Thus we claim to have solved the inverse problem of Pratt Isostasy.

Brian and I were students of Robert P. Meyer, who was a student of George P

Woollard, who devoted much effort to the prediction of gravity from geology.
So we had an appropriate scientific heritage.

* See and