The Revelle will depart from Pago Pago May 9 and end in Honolulu May 29. Water depths here are 3 to 5.5 kms and the region is thickly sedimented. Our objectives are to determine the crustal grain here with Seabeam, SCS, and gravity, to ascertain ancient spreading directions, to look for M series anomalies parallel to either scarp, to determine the seismic stratigraphy across the scarps to compare with the Rapuhia and Wishbone scarps, and to model the gravity field to study crustal thickness variations. Magnetic surveying will determine whether M series anomalies are associated with any of these features and therefore constrain the timing of their formation and tectonic events. Geophysical profiles across the Suvarov Scarp can test if it is a conjugate rift feature to the Rapuhia-Udintsev trend forming the NE border of the Hikurangi Plateau.
Key data are seismic stratigraphic sections and magnetics.
Our data will in combination, determine the type and ages of the plate boundaries in the region near the Manihiki Plateau. Hussong, D. M., L. K. Whipperman, and L. W. Kroenke, The crustal structure of the Ontong Java and Manihiki Oceanic Plateaus, J. Geophys. Res., v. 84, p. 6003-6010, 1979. American Geophysical Union, Monograph 77, p. 171-185. 5. AGU Fall Supplement, p. F721.