Shipboard Cruise Report on Leg Two of Expedition South Tow: Studies in the Southeast Pacific

摘要

The report summarizes Leg 2 of Expedition South Tow, conducted by the R/V THOMAS WASHINGTON from Papeete, Tahiti to Valparaiso, Chile during 15 February - 20 March 1972. Extensive near-bottom geophysical data over the Pacific-Antarctic Rise at 51 degrees S were obtained in order to study the detailed structure of the magnetic time scale between magnetic Anomaly 3 on both sides of the rise crest. Underway bathymetry, magnetic, and navigation plots are included. An excellent surface magnetic profile on the west flank of the Pacific-Antarctic Rise showed Anomalies 1-20 clearly with an abrupt increase in the spreading half-rate from 2.3 cm/yr for anomalies older than Anomaly 5 to 4.8 cm/yr for the younger anomalies. (Author)