This book deals with the most important results achieved in marine geology over the last three decades. Relevant geophysical, geochemical, sedimentological and paleontological methods are briefly described. Information on new results from plate tectonics, marine sedimentation from the coasts to the deep sea, climatological aspects, paleoceanography and the use of the sea floor is presented. The authors attempt to communicate the excitement of marine geological research - both on research vessels and in modern laboratories. Basic mineralogical, geochemical, biological and other relevant data and a detailed list of books and symposia are given in an Appendix. The second edition of "The Sea Floor" is an updated version with many new aspects and illustrations.