In the report by John C. Behrendt et al. "Aeromagnetic and radio echo ice-sounding measurements show much greater area of the Dufek Intrusion, Antarctica" (29 Aug., p. 1014), the word "expedition" should have read "exploitation" in line 13 of the first paragraph on page 1014. Also, in line 2 of the next to last paragraph on page 1016, "50 to 60 cm/sec(2)" should have read "50 to 60 (cm sec(2)) x 10(-3)."