Ocean Bottom Seismometer data from profile OBS2017-1 in the southern Mariana Trench, covering the subducting plate

In 2017, following the successful development of the 10,000-meter-depth OBS, profiles OBS2017-1 was conducted in the southern Mariana Trench aboard the R/V Tan Suo Yi Hao. Profile OBS2017-1 is 430 km-long, oriented parallel to the profiles OBS2017-1 and OBS2016-2 . This study focuses on a 150-km-long segment of the profile OBS2017-1, extending from the Caroline Plateau to the trench axis, including the bend-faulting zone. Fifteen OBS stations were analyzed, including three 10,000-meter-deep instruments (OBS26, 27, 28), which were deployed at depths 8,000–10,000 m and successfully recovered. The seismic survey employed a four-air-gun array with a total volume of 6,000 cubic inches, firing shots every 80 s at an average speed of 5 knots, resulting in a total of 750 shots being fired. This setup enabled detailed examination of the structural variations within the crust and upper mantle as the Caroline Plateau approaches the trench.