P-wave velocity of discrete samples (DPW) from IODP Hole 386-M0085C

P-wave velocity data from discrete samples from the above given hole of International Ocean Discovery Program (IODP) Expedition 386 (Japan Trench Paleoseismology). During the onshore phase of expedition 386, which took place between 2022-02-14 – 2022-03-15 onboard D/V Chikyu, discrete samples for P-wave velocity measurements were taken from the work halves approx. every 2 meter down core using syringes with an inner diameter of 2 cm. Samples measured 2.5–3 cm long for a sample volume of ~10 cubic centimetres. Samples were then shipped to the European Petrophysics Consortium (EPC) laboratory at the University of Leicester (UK) for processing. Measurements were performed with a Geotek P-wave logger for discrete samples (PWL-D). Measurements were attempted for each sample, however, the unconsolidated lithology of some samples proved unsuitable for the instrument (e.g. too soupy or too friable to be placed between the transducers).Operator notes: Data from section numbers > 30 can be associated to a decrease in velocity values, this is likely due to cracks opening in the samples when applying pressure on it at the time of measurement (as observed by operators). For holes M0081E & F Sections 1-29 velocity values are overestimated due to an issue with the calibration.For further methodological information see methods chapter in Strasser, M. et al., 2023 https://doi.org/10.14379/iodp.proc.386.102.2023

本数据集为国际大洋发现计划（International Ocean Discovery Program, IODP）386航次（日本海沟古地震研究）指定钻孔的离散样品P波速度数据。该航次陆上作业阶段于2022年2月14日至2022年3月15日期间在“地球号”（D/V Chikyu）钻探船上开展，研究人员以约每2米的间隔从岩心工作半段中，使用内径2 cm的注射器采集用于P波速度测试的离散样品。所采集样品长度为2.5–3 cm，样品体积约为10立方厘米。随后所有样品被运送至英国莱斯特大学欧洲岩石物理联盟（European Petrophysics Consortium, EPC）实验室进行处理。测试采用Geotek离散样品P波测井仪（Geotek P-wave logger for discrete samples, PWL-D）完成。研究人员尝试对所有样品开展测试，但部分样品的未固结岩性不适用于该仪器（例如过于黏稠或过于松散，无法放置在换能器之间）。操作员备注：井段编号大于30的样品速度数据偏低，这可能是由于测试过程中施加压力导致样品内部产生裂隙（操作员观测所得）。对于M0081E与M0081F钻孔的1-29号井段，由于校准问题导致速度值被高估。更多方法学细节可参考Strasser M等2023年发表的研究中方法学章节，链接：https://doi.org/10.14379/iodp.proc.386.102.2023