This paper presents a new broadband ocean bottom seismograph (OBS) developed by the SUSTech OBS lab for passive-source seafloor seismic observations. This instrument, called Pankun, has several key features that set it apart from traditional OBS instruments. In addition to the seismometer-separated scheme, these features include a unique shielding structure to minimize current-induced noise, a compact gimbal for accurate leveling, and low power consumption for extended operation on the seafloor. The design and testing of Pankun’s primary components are thoroughly described in this paper. The instrument has been successfully tested in the South China Sea, demonstrating its ability to record high-quality seismic data. The anti-current shielding structure of Pankun OBS has the potential to improve low-frequency signals, particularly on the horizontal components, in seafloor seismic data.

This study presents a passive-source ocean-bottom seismograph (OBS) experiment conducted in the southwest subbasin of the South China Sea (SCS) aimed at exploring the geodynamic processes shaping this short-lived oceanic basin. The successful deployment and recovery of 24 passive-source OBS units, including 14 I-7C types and 10 Pankun OBS units, resulted in the acquisition of one of the most extensive passive-source seismic data sets ever recorded in the SCS. We provide comprehensive details of the experiment, with a focus on evaluating the data quality and performance of the Pankun OBS units. This evaluation includes assessments of horizontal orientation determination, leveling system effectiveness, timing accuracy, and ambient noise spectrum. In addition, we compared the waveforms recorded by the Pankun OBS units with those from land stations and I-7C units, as well as the noise spectra between Pankun and global OBSs using the same seismometer. Although these comparisons suggest that the Pankun OBS achieves satisfactory performance, we identified a few inadequacies with this new instrument, such as issues with the differential pressure gauge, clock shifts, and sensor package calibration.

This paper presents a new broadband ocean bottom seismograph (OBS) developed by the SUSTech OBS lab for passive-source seafloor seismic observations. This instrument, called Pankun, has several key features that set it apart from traditional OBS instruments. Besides the seismometer-separated scheme, these features include a unique shielding structure to minimize current-induced noise, a compact gimbal for accurate leveling, and low power consumption for extended operation on the seafloor. The design and testing of Pankun's primary components are thoroughly described in the paper. The instrument has been successfully tested in the South China Sea, demonstrating its ability to record high-quality seismic data. The anti-current shielding structure of Pankun OBS has the potential to improve low-frequency signals, particularly on the horizontal components, in seafloor seismic data.

This article describes an ocean-bottom seismic data set collected offshore New Zealand’s North Island as part of a multinational amphibious experiment investigating the Auckland volcanic field. From August 2023 to September 2024, 20 broadband ocean-bottom seismographs were deployed at water depths of 1200–2700 m, yielding approximately one year of continuous recordings from 15 successfully recovered instruments. We present comprehensive quality metrics including instrument orientations (determined via Rayleigh-wave polarization with uncertainties < 7.5°), tilt characteristics (predominantly < 2.5°), and clock drift corrections (achieved to 0.1 s precision using ambient noise cross correlation for five units lacking Global Positioning System synchronization). The data set exhibits excellent signal fidelity in the microseismic band (2–20 s), with vertical components showing substantially lower noise than horizontal components. Notably, two instruments (R12 and R42) had a delayed recovery, and recorded 16–18 months of continuous data. All data will be publicly archived at the U.S. National Geophysical Facility Data Repository following a three-year proprietary period, providing critical offshore coverage to complement New Zealand’s land-based seismic network for studies of intraplate volcanism and subduction zone dynamics.