Editor＇s Note

P. R. Castillo is a Professor of Geology at Scripps Institution of Oceanography （SIO）, University of California at San Diego. He received a BSc from University of the Philippines in 1977, an MSc from University of Akron （USA） in 1983, and a PhD from Washington University （USA） in 1987. He held positions at Carnegie Institution of Washington and University of Miami before he joined SIO in 1990.