Acknowledgments

Jon Claerbout's encourangement and challenging suggestions motivated my interest in the subject. I am also grateful to Biondo Biondi, Gennady Ryzhikov, Bill Harlan, Jim Berryman, Bill Symes, Dave Nichols, and Yalei Sun for insightful discussions. The topic of regularization deserves a more detailed study than this short paper, and I hope to continue discussing it with the experts.

The 3-D North Sea dataset was released to SEP by Conoco and its partners, BP and Mobil.