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doi:10.2204/iodp.sp.333.2010 Sampling planExpedition 333 will sample retrieved cores following traditional IODP policy, including discrete samples, whole-round samples (both individual requests and "community whole rounds"), and sample clusters (see additional explanation of community whole rounds and sample clusters in "Sampling sediment cores"). The sampling strategy was developed by the NanTroSEIZE PMT in consultation with the Sample Allocation Committee (SAC) (see "Sample requests and coordination") to best meet the project's objectives and the individual desires of the science party. A short review of core sampling and archiving is provided below. Shipboard and shore-based researchers should also refer to the IODP Sample, Data, and Obligations Policy (www.iodp.org/program-policies/). Sampling sediment coresCores are typically split into a "working half" and "archive half," with the working half being available for sampling by shipboard and shore-based scientists. Although the archive half is also available for sampling in certain circumstances, it is primarily designed to preserve retrieved material while providing flexibility and broader access to important material postcruise. Samples of whole-round cores can also be requested following IODP policy. The multiexpedition nature of NanTroSEIZE requires modification of normal IODP sampling policy and routines in sampling sediment cores. Specifically, these include: (1) community whole-round cores that are archived (at the Kochi Core Center [KCC]) for postcruise distribution and (2) co-located sample clusters taken as a suite from slices (1–2 cm thick) next to all whole rounds. Sampling basement coresSampling of basement cores is typically handled in a more deliberate manner, particularly if recovery is limited. Once the cores are split, interested scientists will be able to identify specific pieces or features (e.g., veins) for sampling, and adjustments will be made if more than one request is made for the same piece. If the amount of time available for basement sampling is insufficient because it is planned as a later part of the expedition, this part of the sampling plan could be implemented after the expedition at the KCC. Community whole-round samplesAs usual, individual scientists will be able to collect whole-round samples for their postcruise research. In addition, however, we will collect "community" archive whole-round samples to augment and/or provide redundancy for those requested by shipboard scientists. The goal is to preserve samples for a wide range of overall science objectives over the duration of NanTroSEIZE. Community whole-round samples are typically collected from each core, depending on the length of each recovery. This strategy, for example, will enable additional analyses of critical intervals once those zones are identified from initial shore-based laboratory tests. Sample clustersTo maximize the project's ability to correlate different shipboard and shore-based data sets, it will be essential to co-locate suites of basic data types (pore water, organic geochemistry, carbon/carbonate, moisture and density, bulk-powder X-ray diffraction [XRD], and bulk chemistry X-ray fluorescence). Sample clusters are normally collected next to each whole-round specimen, including those used for interstitial water geochemistry. Clusters will also include subsamples for shore-based measurements of grain size, clay mineral XRD, microfabric, and cation exchange capacity as specified by individual sample/data requests. Sample requests and coordinationNanTroSEIZE is a long-term drilling project with several linked expeditions over several years. Consequently, sampling and coordination of individual samples and data requests are somewhat different than for single expeditions. These differences include the role of Specialty Coordinators, data sharing opportunities, and a more integrated sample/data request program that includes use of designated labs for some shore-based analyses. Key aspects of these differences are described below. Specialty CoordinatorsUnlike traditional stand-alone Ocean Drilling Program/IODP legs and expeditions, unusual amounts of coordination and collaboration must occur among different science parties to achieve NanTroSEIZE goals. Specialty Coordinators, in collaboration with Co-Chief Scientists, will be responsible for facilitating collaborations between the participants of Expeditions 322 and 333. They will also identify research or sampling gaps, help organize efficient sampling strategies (to minimize redundancy and overlap), and facilitate collaborations beyond those planned by the shipboard science party for Expedition 333. The Specialty Coordinators will also provide technical and scientific guidance to the science party before and during the expedition to ensure seamless data sets, particularly with respect to existing shipboard data from Expedition 322. The NanTroSEIZE PMT has identified six specific research areas that require the oversight of Specialty Coordinators over the project's duration:
Data/Sample sharing between expeditionsData sharing across expeditions is normally accommodated through a formal data/sample request; that is, a scientist from one expedition can apply as a shore-based scientist for data/samples from a completed or planned expedition. In the case of NanTroSEIZE, contingency operations sometimes overlap across two or more expeditions to such an extent that the expeditions are considered one expedition in terms of shipboard data and samples. In such cases, data can be shared without a separate data/sample request. This type of merger may occur, for example, for scientific or logistical reasons during preexpedition planning. It could also occur during an expedition if contingency sites are drilled that overlap with another planned expedition. The decision as to whether an expedition is a stand-alone or merged in terms of data/samples is made by the NanTroSEIZE PMT in consultation with the SAC and the Co-Chiefs of the involved expeditions. In the case of Expedition 333, it is also important to realize that members of the science party for Expedition 322 will be interested in collaborative postcruise research using samples from intervals that had not been cored before. Balancing the research interests of individual scientists from both expeditions against the project's needs for seamless data sets at each site will be a responsibility of the Specialty Coordinators. The desire will be to enhance opportunities for fruitful collaboration. Community labs for postexpedition analysesWhereas many analyses can and will be conducted at sea, others require state-of-the-art instrumentation that is only available on shore. We are particularly concerned about stable isotopic measurements that depend on dedicated instruments not found at all universities and government laboratories. For example, we expect to collect pore water to measure at least Sr, B, Li, O, H, Cl, and C stable isotopic compositions. It is doubtful that any individual scientist has the on-site capability to make all of the measurements listed above. Issues regarding quality assurance/quality control become significant. To get the most consistent and reliable data for all Stage 1 expeditions, the NanTroSEIZE PMT proposed that all samples for each category of geochemical analysis go to a single laboratory. Several laboratories (to be determined) will have to be involved. For example, one laboratory might measure O, H, and C isotopes while another might measure Cl isotopes or Li. The choice of a particular laboratory (and analytical technique) will be reached by consensus of the inorganic geochemists who sail on Expedition 333, mediated by the Specialty Coordinator for Geochemistry and approved by expedition SACs. We anticipate that data generated from each laboratory will be shared by all members of the Expedition 322 and 333 scientific parties for use as defined by the approved research plans. Similarly, shore-based collaborators who are part of the community team will be granted access to the results of shipboard geochemical analyses at the earliest convenience (i.e., as site reports are completed). This strategy was implemented successfully during the postexpedition phase of NanTroSEIZE Stage 1. Sample and data requests (research proposals)All shipboard scientists must submit at least one data or sample request in advance of the drilling expedition. Additional requests also may be submitted during or after the expedition if appropriate. The initial sample requests provide the basis for the SAC and Specialty Coordinators to develop an integrated sampling program of both shipboard and postcruise sample requests. Careful planning and vertical mapping of sample distributions is particularly important for whole-round sampling. The initial sampling plan, of course, will be subject to modification depending upon the actual material/data recovered and on collaborations that may evolve between scientists before and during the expedition(s). Substantial modifications to the sampling plan during the expedition require the approval of the SAC. To provide enough time for the SAC and Specialty Coordinators to develop a detailed and integrated sampling strategy, sample requests are due by 15 November 2010. The IODP Sample, Data, and Obligations Policy (www.iodp.org/program-policies/) outlines the policy for distributing IODP samples and data and defines the obligations incurred by both shipboard and shore-based scientists. Both groups of scientists should also use the Sample/Data Request form (smcs.iodp.org/) in submitting their requests. Additional sampling guidelinesThe SAC is composed of Co-Chief Scientists, Expedition Project Managers, the shipboard curatorial representative, and the IODP curator on shore; the SAC for the expedition(s) must approve access to data and core samples requested during the expedition and during the 1 y moratorium, which starts at the end of the drilling expedition. It is important to note that Specialty Coordinators merely provide advice to the SAC within their fields of expertise; they are not responsible for the decisions to approve/revise/reject the sample/data requests. All sample frequencies, spacing, and sizes must be justified on a scientific basis. Implementation of the sampling plan will depend on core recovery, the full spectrum of other sample/data requests, the expedition objectives, and project-wide NanTroSEIZE objectives. When critical or volumetrically limited intervals are recovered, there may be considerable demand for samples because of the limited amount of cored material. These intervals (e.g., highly deformed fault zone) may require special handling, a higher sampling density, reduced sample size, or continuous core sampling for a set of particular high-priority research objectives. With advice from Specialty Coordinators, the SAC may request an additional formal sampling plan before critical intervals are sampled. All sampling to acquire ephemeral data types (e.g., for microbiology) or to achieve essential sample preservation will be conducted during the expedition. Most sampling for each individual scientist's postcruise research will be conducted during the expedition, but some sampling could be deferred to postcruise. A postexpedition sampling party is particularly likely for cores collected during the final days of the expedition. |
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