近日，南方科技大学胡佳顺团队报道了夏威夷热点纵向运动的动力学和夏威夷帝王湾的形成。这一研究成果发表在2025年9月23日出版的《美国科学院院刊》杂志上。

夏威夷帝王湾的形成一直是一个关键的地质难题，涉及板块构造和羽流动力学。受古地磁资料的限制，南向热点运动被认为是弯曲形成的主要原因，但纵向热点运动的作用在很大程度上被忽视了。

研究组分析了夏威夷热点运动主题板块运动学和热点轨道之间的地理距离。这两种分析都表明夏威夷热区有大量的纵向运动。进一步应用全球地幔对流模式发现，除了弯曲前后的向南运动外，还存在向西（~6°）再向东（~2°）的热点漂移，其中向西运动主要受东北太平洋洋内俯冲控制。

研究组人员发现西向运动和南向运动都需要适应海山链，前者贡献了大量的~20度的弯曲角，不少于后者，挑战了传统的观点。结合地球动力学预测的47 Ma太平洋板块运动变化，他们的模型提供了一个几乎完美的海山链拟合。这一结果表明，夏威夷的地幔柱导管向西南倾斜，为地震学研究中长期存在争议的夏威夷地幔柱的存在提供了强有力的证据。

附：英文原文

Title: Dynamics of longitudinal Hawaiian hotspot motion and the formation of the Hawaiian-Emperor Bend

Author: Zhang, Jie, Hu, Jiashun

Issue&Volume: 2025-9-23

Abstract: Formation of the Hawaiian-Emperor Bend has been a key geological puzzle that involves both plate tectonics and plume dynamics. Constrained by paleomagnetic data, southward hotspot motion has been considered a major contributor to the formation of the bend, but the role of longitudinal hotspot motion remains largely overlooked. Here, we analyze the Hawaiian hotspot motion using plate kinematics and geographical distances between hotspot tracks. Both analyses indicate a substantial longitudinal Hawaiian hotspot motion. Further application of global mantle convection models reveals a westward (by ~6°) and then an eastward (by ~2°) hotspot drift in addition to the southward motion before and after the bend, with the westward motion primarily controlled by the intraoceanic subduction in Northeast Pacific. We find that both the westward and southward motion are required to fit the seamount chain, with the former contributing a substantial amount of ~20 degrees to the bend angle, no less than the latter, challenging traditional views. Combined with a geodynamically predicted Pacific Plate motion change at 47 Ma, our model provides a nearly perfect fit to the seamount chain. This result suggests that the Hawaiian plume conduit is tilted toward the southwest, providing a strong indication for the source of the Hawaiian plume that has long been debated among seismological studies.

DOI: 10.1073/pnas.2510972122

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2510972122