物探化探计算技术2025，Vol.47Issue(3)：340-351,12.DOI:10.12474/wthtjs.20240313-0001
波场梯度法在阿拉斯加地区的应用研究
Application of wave gradiometry method in Alaska
摘要
Abstract
In this paper,Rayleigh wave phase velocity distributions at periods of 20s～150s in Alaska are obtained using wave gradiometry method.Our results provide new references and constraints for the structural characteristics and tectonic deformation in the subduction zones of Alaska.At periods of 20s～30s,the low-velocity zone corresponds to the region north of the Kobuk fault and south of the Denali fault,which is consistent with thick crust in these areas.The Wrangell Volcanic Field is a distinct low-velocity anomaly,which may be a reflection of a big magma chamber.At periods of 50 s and longer,the high-velocity anomaly in the south-central region characterizes the subducting Pacific-Yakutat plate,the high-velocity anomaly in the north indicates the thick and cold lithosphere of Arctic Alaska Terrain and North American Craton.At the same time,the mantle wedge shows a distinct low-velocity anomaly.The distribution of low-velocity anomalies in the Pacific plate back-arc region corresponds well to the volcanoes in the western Alaska coast at 50 s and more extended periods.Combined with previous studies,we suggest that the magma of these volcanoes may originate from the thermal upwelling of the big mantle wedge.In addition,Denali Volcanic Gap shows an average velocity at a period of 20s～30s,indicating that there may be a lack of magmatic activity in the mantle wedge of the Yakutat slab.关键词
波场梯度法/瑞利波相速度/岩石圈结构/太平洋-雅库塔特俯冲带/德纳利火山空区Key words
wave gradiometry method/rayleigh wave phase velocity/lithospheric structure/pacific-Yakutat subduction zone/Denali Volcanic Gap分类
地质学引用本文复制引用
刘智金,梁春涛,陈春美,曹飞煌..波场梯度法在阿拉斯加地区的应用研究[J].物探化探计算技术,2025,47(3):340-351,12.基金项目
国家重点研发计划项目(2022YFF0800601) （2022YFF0800601）
国家自然科学基金项目(42174071) （42174071）
四川省重点研发计划项目(23ZDYF2412) （23ZDYF2412）
