Conamara Chaos Region, Europa: Reconstruction of mobile polygonal ice blocks
Conamara Chaos Region, Europa: Reconstruction of mobile polygonal ice blocks
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欧罗巴科纳马拉混沌地区：移动多边形冰块的重建
DOI：
10.1029/1998gl900176
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发表时间：
1998
影响因子：
5.2
通讯作者：
R. Pappalardo
中科院分区：
文献类型：
--
作者：
N. Spaun;James W. Head;Geoffrey C. Collins;L. Prockter;R. Pappalardo
伽利略号拍摄的欧罗巴新图像显示，在高度线性的背景平原上，地形混乱。对科纳马拉混沌的研究表明，该地区的59%由位于低海拔的细纹理基质材料组成，并由线性平原破坏形成，而其余部分由139个线性纹理背景平原的碎片多边形组成。使用直通线性特征，我们重建了混沌多边形的原始位置，发现发生了显著的横向平移和旋转：78%的多边形经历了水平平移，大多数移动在1到5公里之间，81%旋转（平均旋转11°）。多边形的运动似乎是从混乱的边缘向内和顺时针方向在中心，而多边形的旋转是均匀的顺时针和逆时针方向。因此，该区域的混沌形成涉及破坏超过一半的预先存在的地形，以及剩余多边形的移动，平移和旋转，这意味着近地表温度升高，并且在100 km的横向尺度上具有高度移动的基底。
New Galileo images of Europa reveal regions of chaotic terrain in otherwise highly‐lineated background plains. Examination of Conamara Chaos shows that 59% of the region is composed of fine‐textured matrix material lying at low elevations and formed by destruction of lineated plains, while the remainder consists of 139 fragmented polygons of linear‐textured background plains. Using through‐trending linear features, we reconstruct the original positions of chaos polygons and find that significant lateral translation and rotation have occurred: 78% of the polygons have undergone horizontal translations with most moving between 1 and 5 km, and 81% have rotated (average rotation of ∼11°). Movement of polygons appears to be inward from the chaos margins and clockwise in the center, while polygon rotation is evenly clockwise and counterclockwise. Chaos formation in this region thus involves destruction of over half of the pre‐existing terrain, and mobilization, translation, and rotation of the remaining polygons, implying elevated near‐surface temperatures and a highly mobile substrate over lateral scales of ∼100 km.