Hawaii Deep Water Cable Program : plan for the second bottom roughness survey cruise of the Alenuihaha Channel, June, 1986

Abstract

This document is a general plan for the second Bottom Roughness Cruise of the Alenuihaha Channel for the Hawaii Deep Water Cable Program. The survey will be conducted by the Scripps Institute of Oceanography utilizing the vessel NEW HORIZON and the research vehicle DEEP TOW in June of 1986. This plan outlines the goals, requirements, schedule and surveying techniques: it is to be used as a guideline in preparation for this cruise. An eight-day Bottom Roughness Cruise was performed in October/November, 1985, of the Alenuihaha Channel using the MOANA WAVE and a bottom roughness survey package specifically developed for this cruise, This survey was the first detailed look at the bottom roughness in the Alenuihaha Channel. Its purpose was to characterize the bottom roughness in terms meaningful to the HDWC cable laying process. It attempted to find an acceptable cable path across the Alenuihaha Channel, identify the degree of placement accuracy required for the successful deployment of the cable, to identify an optimal bottom cable tension and to identify the needs for subsequent surveys. In addition to accurately measuring the bottom roughness, the first survey included operating the Sea MARC II, a wide-swath sidescan sonar system, over the area. A cruise report is available with all the profiles and side scan data illustrated.