Despite numerous observational and geodynamic modeling studies, the presence of the northwest Pacific slab tear and its influence on mantle dynamics remain controversial. By imaging the mantle transition zone (MTZ) discontinuities beneath the Japan Sea and adjacent areas, we demonstrate an ESE-WNW elongated zone with significant MTZ thinning extending from central Honshu, Japan, to the Korean Peninsula, which provides additional supporting evidence for the existence and distribution of a large-scale slab tear. Our results, when combined with other geophysical and geochemical evidence, indicate that the hot mantle material oceanward of the slab may flow through the slab tear and contribute to surface volcanism. Substantial MTZ thickening is widely observed in the region south of the slab tear and suggests the existence of slab stagnation, possibly related to the strong resistance at the bottom of the MTZ.

中文翻译：

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俯冲西北太平洋板块的停滞和撕裂

尽管进行了大量的观测和地球动力学建模研究，但西北太平洋板片撕裂的存在及其对地幔动力学的影响仍然存在争议。通过对日本海和邻近地区下方的地幔过渡带（MTZ）不连续性进行成像，我们展示了一个从日本本州中部延伸到朝鲜半岛的具有明显 MTZ 减薄的 ESE-WNW 拉长带，这为存在的存在提供了额外的支持证据并分布大面积的板坯撕裂。我们的结果与其他地球物理和地球化学证据相结合，表明板块向海洋的热地幔物质可能流过板块撕裂并有助于地表火山活动。在板片撕裂以南的区域广泛观察到大量的 MTZ 增厚，表明存在板片停滞，