Long-term broadband underwater acoustic recordings from McMurdo Sound, Antarctica (2017-2019)

Abstract: Broadband underwater acoustic recordings from the McMurdo Oceanographic Observatory mooring near the seaward terminus of the McMurdo Station seawater intake jetty. An omnidirectional Ocean Sonics icListen hydrophone (SB2-ETH, SN 1713) recorded continuously at 512 kilosamples/second (256 kHz Nyquist frequency; 24 bit) for 2 years. The hydrophone was mounted vertically on a steel strut (insulated with rubber sheet) at about 70 cm above the mud/gravel seabed at 21m deep, with the sloping 45° rubble face of the jetty just behind the hydrophone. Temporal coverage is >90%, with gaps and truncated files arising due to network and power outages and software bugs. The audio recordings are 10 minute WAV files, compressed using the lossless FLAC code (Free Lossless Audio Codec, xiph.org; about 33MB of data/minute compressed; 100MB/min uncompressed). The hydrophone was under thick (to 3 m) sea ice cover for the majority of the dataset. The majority of the recorded biological sounds were produced by Weddell seals. Orca were present intermittently (~10 days total) in January-March in both summers. Known non-biological sounds include irregular low-intensity, broad-spectrum clicks and cracks from the sea ice cover, occasional wind noise, a 1.5-s gurgle with components to 200kHz every 90s from the CTD’s pump, a broad-spectrum mechanical sound for 3 min every 4 h from the observatory's underwater camera cleaning system, low-intensity whines (about 18, 58, 83, and 130 kHz, though variable over the dataset) thought to be from the station seawater pumps (>100 m away within the jetty’s well casing), and intermittent noises from tracked-vehicles and helicopters (September–February), SCUBA divers (October–December), and ships (January). Given hosting limitations, only every 6th file (roughly 10min/hour) has been archived here. Additional data can be obtained by contacting the primary author of the dataset, who will maintain it for as long as possible. Audio spectrogram images (PNGs) at three frequency ranges (three stacked panels per image, upper limits of 2.5, 25, and 256 kHz) from the entire dataset (all data, not subsampled) are also archived separately.摘要：本数据集源自部署于麦克默多站（McMurdo Station）海水取水码头近海端附近的麦克默多海洋观测站锚系平台获取的宽带水下声学录音。本次采集使用一台全向型Ocean Sonics icListen水听器（hydrophone，型号SB2-ETH，序列号SN 1713），以512千采样每秒的采样率（奈奎斯特频率256 kHz，采样精度24比特）进行了连续两年的录音。该水听器垂直安装于钢制支架（包裹橡胶绝缘层）上，部署于水深21米处，距离泥砾质海底约70厘米，水听器后方紧邻码头45度倾斜的碎石坡面。数据集的时间覆盖率超过90%，因网络中断、电力故障及软件缺陷存在部分数据缺口与截断文件。 录音文件为10分钟时长的WAV格式，采用无损FLAC（Free Lossless Audio Codec，xiph.org）编码压缩，单分钟压缩后数据量约33 MB，未压缩状态下为100 MB/分钟。数据集的绝大多数时段内，水听器处于厚度可达3米的海冰覆盖之下。本次录制的生物声学信号绝大多数源自威德尔海豹。虎鲸会间歇性造访该海域（累计约10天），出现在每年夏季的1月至3月期间。 已识别的非生物声学信号包括：海冰覆盖层产生的不规则低强度宽频谱咔哒声与破裂声；偶发的风噪声；温盐深仪（CTD，Conductivity-Temperature-Depth）泵每90秒产生一次、时长1.5秒、频谱成分可达200 kHz的汩汩声；观测站水下相机清洁系统每4小时产生一次、持续3分钟的宽频谱机械噪声；被推测来自码头井套内100米外的站区海水泵的低强度嗡鸣声（频谱峰值约为18、58、83与130 kHz，具体数值随数据集存在波动）；以及履带式车辆与直升机（9月至次年2月）、水肺潜水员（10月至12月）和船舶（1月）产生的间歇性噪声。 受限于存储容量限制，本平台仅存档了每6个文件中的1个（约合每小时留存10分钟的录音数据）。若需获取完整数据集，可联系本数据集的第一作者，其将尽可能长期维护该数据集。此外，针对完整原始数据集（未进行抽采样处理）生成的三种频段范围的声谱图（PNG格式，单张图片包含三个堆叠面板，频率上限分别为2.5 kHz、25 kHz与256 kHz）已单独存档。