Three‐dimensional density modeling of the EGM2008 gravity field over the Mount Paekdu volcanic area
Three‐dimensional density modeling of the EGM2008 gravity field over the Mount Paekdu volcanic area
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DOI：
10.1002/jgrb.50266
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
Sungchan Choi;C. Oh;H. Götze
中科院分区：
文献类型：
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作者：
Sungchan Choi;C. Oh;H. Götze
在这里，我们使用全球重力场数据集EGM 2008对位于朝鲜和中国边境的白头山成层火山及其周边地区进行三维地壳密度建模。曲率分析和欧拉反褶积用于辅助解释，三维模型受到多个地质和地球物理数据集的约束。白头山的特征是布格异常低，为-110 × 10-5 m/s2，这是由以下因素的综合重力效应造成的：（1）莫霍面深度约为40 km，（2）P波速度和密度低于周围的区域，（3）表面上的低密度火山岩，以及（4）存在以前未被发现的岩浆房。模拟的岩浆房平均厚度为5 km，密度约为2350 kg/m3，距离地表<10 km。在望天山和南波泰山下也有岩浆室的模型。然而，三维密度建模的结果并没有证实之前提出的在白头山以北70公里的地区存在中地壳低速带。自上新世以来，白头山地区的火山活动从朝鲜东海岸向西北方向迁移，沿着西北-东南向断层的路径。
Here we use the global gravity field data set EGM2008 for 3‐D crustal density modeling of the Mount Paekdu stratovolcano and surrounding area located on the border between North Korea and China. Curvature analysis and Euler deconvolution are used to assist interpretation, and the 3‐D model is constrained by multiple geological and geophysical data sets. Mount Paekdu is characterized by a low Bouguer anomaly of −110 × 10−5 m/s2, which is caused by the combined gravity effects of (1) a depth to the Moho of about 40 km, (2) a zone with lower P wave velocity and density than the surrounding, (3) low density volcanic rocks on the surface, and (4) the presence of a magma chamber that has not previously been identified. The modeled magma chamber has a mean thickness of 5 km and a density of about 2350 kg/m3 and is located <10 km from the surface. Magma chambers are also modeled beneath Mount Wangtian and Mount Nampotae. However, the results of the 3‐D density modeling do not confirm the existence of a previously proposed midcrustal low‐velocity zone in the area 70 km to the north of Mount Paekdu. Since the Pliocene, volcanic activity in the Mount Paekdu region has migrated from the east coast of North Korea to the northwest, following the path of NW‐SE trending faults.