Plates and their motions

The last reviews which covered research in plate motions were those of Herron and Pitman [1975] on marine magnetic anomalies and Dewey [1975] on plate tectonics, both reporting on research for the period 1971–1974. In the last 12 years there has been considerable refinement of relative motion models, as well as further development of global models. Also, major effort has gone into defining reference frames for the study of plate motions, and discriminating between them. More recently, the role of errors in individual plate rotations and the associated uncertainties in reconstructions have received attention. In this report I concentrate on work published in the last 4 years, 1983–1986, citing a minimum of publications from previous years; however, some papers in press for early 1987 have been included. This report first reviews work on relative plate motions for the present and past, and reconstructions, and then models for these motions, global ones for driving forces and local ones determining subduction history and back‐arc spreading. The problem of reference frames, both hotspot and paleomagnetic, is discussed next. I end with a review of work on the errors in plate motions.