This map, by Augustus Petermann, was the first bathymetric map of the
Pacific Ocean. Data was acquired by the CHALLENGER, the USS TUSCARORA, and the
German research ship GAZELLE. Note the much denser sounding information on the
TUSCARORA as the result of first use of piano-wire sounding. Note the Tuscarora
Deep, first discovery of a trench, today called the Japan-Kuril Trench.