Expedition 396 methods

Abstract

publications.iodp.org • 3 known because of the deviation of the pipe below the ship, which can vary depending on water currents, tides, and water depth; the hole position is thus known typically within 10 m accuracy.Drilling sites were numbered according to the series that began with the first site drilled by the D/V Glomar Challenger in 1968. Starting with Integrated Ocean Drilling Program Expedition 301, the prefix "U" designates sites occupied by JOIDES Resolution. When drilling multiple holes at a site, hole locations are typically offset from each other by ~20 m. During Expedition 396, we offset holes at an average of 115 m, except for Site U1570, where holes were offset as far as 1772 m. Site U1570 was approved by EPSP as a 2 km long "ribbon" or transect west of Site U1569 with start and end coordinates. This ribbon provided an alternate coring strategy to Site U1569, where deep stratigraphic targets were outcropping at shallower subseafloor depths. A letter suffix distinguishes each hole drilled at the same site. The first hole drilled is assigned the site number modified by the suffix "A," the second hole takes the site number and the suffix "B," and so forth. During Expedition 396, 21 holes were drilled at 10 sites (U1565-U1574; see Figure F4 in the Expedition 396 summary chapter [Planke et al., 2023a]).