Erratum
In table 1 of the report "Rock avalanches caused by earthquakes: Source characteristics" by David K. Keefer (23 Mar., p. 1288), data for location 20 (Buller River Canyon, New Zealand) was incorrect. Under the column headings "Intense fracturing," "Planes of weakness dipping out of slope," and "Previous slidest," the entries should have been "Yes" rather than "No." In addition, the following citation should have been included in reference 13: M. R. Johnston, Trans. N.Z. Inst. Eng. 1, 239 (1974).