长白山火山地壳岩浆系统的背景噪声波形伴随成像研究

位于中朝边境的长白山火山是中国现存规模最大、保存最为完整和潜在喷发危险最强的活火山，其在公元946年的“千年大喷发”被认为是有人类历史记载以来的最大火山喷发事件之一。2002至2005年间增强的火山岩浆活动使长白山火山存在近期喷发危险性的讨论成为国内外广泛关注的地学热点问题，但人们目前对其下方地壳岩浆系统的了解却十分不足，已有的研究对长白山火山壳内岩浆房存在的深度位置、形态规模及其部分熔融程度的认识仍存在较大分歧。本项目将汇集长白山火山及邻区（包括朝鲜境内）多个密集流动地震台阵和区域固定地震台网的观测资料，采用新近发展的背景噪声波形伴随成像方法反演建立长白山火山区高分辨率的三维地壳速度模型，以精细刻画长白山火山地壳岩浆系统，揭示地表火山活动的岩浆来源，为深入理解长白山陆内火山作用的形成、演化及喷发机制提供精细的地震学约束。

The Changbaishan volcano, geographically straddling the border between China and North Korea, is the volumetrically largest, most well-preserved and also hazardous active volcano in China. Its “Millennium eruption” occurred around 946 Common Era is identified to be one of the largest explosive volcanic events ever recorded in human history. Recently, a growing concern over the instability of this potentially hazardous volcano manifested by increased magmatic activities during 2002 and 2005 has drawn much attention from the geoscientific community. However, the crustal structure related to the magmatic pluming system underlying this volcano has not been well constrained. Previous research findings still remain hotly debated in terms of the depth extent, spatial distribution and the degree of partial melting associated with the crustal magma chamber. Here we propose to first collect all the available seismic data from several portable arrays and the local permanent network densely distributed around the Changbaishan volcano (including those from the North Korean side). Then we will apply the newly developed ambient noise adjoint tomography to the seismic data in order to construct a high-resolution 3D crustal velocity model in the Changbaishan volcanic field. Our research goal is to decipher the detailed crustal magmatic pluming system beneath the volcano, and to provide seismic constraints on the formation, evolution and eruption mechanisms related to the intraplate volcanism of the Changbaishan volcano.