Lateral variations in bulk density and porosity of the upper crust of the Moon

We determined variations in bulk density using most recent GRAIL gravity model GL1500 (Park et al., 2015) together with LOLA derived topography (Smith et al., 2017), both available on the Planetary Data System (https://pds.nasa.gov). Using the estimated bulk densities in combination with grain densities estimated from surface composition, the porosity of the upper crust was determined. Each grid point with a spacing of 0.75 deg was calculated using a circular analysis region of 3 deg radius. The grids are equally sampled following the sample theorem of Driscoll and Healy (1994).

本研究借助最新的GRAIL重力模型GL1500（Park等人，2015）以及由LOLA（Lunar Orbiter Laser Altimeter）反演得到的地形数据（Smith等人，2017）开展体密度变化分析，上述两类数据均可从行星数据系统（Planetary Data System, PDS，https://pds.nasa.gov）获取。结合估算得到的体密度与从表面成分反推的颗粒密度，本研究确定了上地壳的孔隙度。本研究采用半径为3°的圆形分析区域，对间距为0.75°的每个网格点进行计算。所有网格均遵循德里斯考尔与希利（Driscoll and Healy，1994）提出的采样定理实现均等采样。