1. Introduction 　　　　　　　　　　　　　　　　　　　　　　　　

The trip to the Hawaiian water in the summer of 2001 must be one of most unforgettable voyages for the shipboard scientists both from Japan and USA. It may be more so for the people who supported this cruises in JAMSTEC (e.g., Mr. Nakai), for the Ship Crew led by the Captain Mr. Ukekura and for the ROV Operating Team led by Mr. Hirata. After the ship accident in the early spring of 2001, ROV search for the sunken site of the fishery training ship Ehimemaru was added as the task of the JAMSTEC Hawaii cruise. Our ship schedule was thus modified several times before we started Japan and revised every week even while we are at the sea. Furthermore, we were awakened at off coast of Maui Island by the shocking news in the early morning of September 11^th.  Due to the emergence in the air traffic, three Japanese (Drs. S. Umino, T. Matsumoto and N.Geshi) who tried to join the ship on Sept.15^th could not fly from Japan.  The ship remained nearly a month in the Hawaiian water after we got off at Honolulu on Sept. 20^th and finally returned JAMSTEC port on Oct. 31^st, 2001.  Because of the strenuous effort of the ship people, we could accomplish under this difficult condition as many as 17 ROV dives (more than we originally planned) and nine piston cores acquired at far distance from Hawaiian archipelago.

The 2001 JAMSTEC Hawaii Cruise has been carried out with ROV-Kaiko and its mother ship Kairei. The Cruise was subdivided into following Legs and Segments: Leg-1 Seg. A (the Piston Core Leg, Aug. 15-Aug 25), Leg-1 Seg-B (West of Oahu Island, Aug. 26-Aug.31), Leg-2 Seg. A-1 (Hilina South Kona, Sept.1-Sept.8), Leg-2 Seg. A-2 (Haleakala and Kohala, Sept.9-Sept.15) and Leg-2 Seg. B (South Arch and North Kona, Sept.16-20).   Scientific outcomes of the 2001 Hawaii Cruise are enormous and innumerable. Just to show some example; 1) First and most comprehensive collection of turbidite layers around the Hawaiian Islands in the form of piston cores, 2) reconnaissance samplings at the great Hana ridge (to the 150km east of Haleakala volcano), 3) complete cross section of the deep root of Kilauea volcano acquired at the west end of the Hilina slump, 4) precious dive at the South Arch representing the southernmost edge of the Hawaiian plume. 

During the seabeam survey in the west of Oahu Island, we unexpectedly found a large yet unrecognized volcano (tentatively called West Oahu volcano here). The volcano is almost 100km in diameter with very gentle slope (submarine low shield) and about 1 km elevation from the normal sea floor. It consists of numerous flat-topped volcanic cones and many steep pointed volcanic cones. Preliminary sampling by ROV at two different localities on the volcano suggests that the volcano records long volcanic activity similar in age to the subaerial volcanoes on Oahu Island (Waianae and Koolau). 

These are just example of numerous new findings in the 2001 Hawaii Cruise. Abundant rocks and core samples just arrived to the hands of researchers wait years of analysis. Clearly the cruise was a great reconnaissance to the 2002 Hawaii cruise in which manned submersible dives using Shinkai 6500 are being planned for the focused target areas.

With gratitude to all people who supported 2001 Hawaii Cruise,

                                    Chief Scientist, Eiichi TAKAHASHI

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