October 17, 2013
Big Cut Dome
image by Rik ter Horst
|No one knows the exact structural reasons that result in so many rilles occurring near the Moon's center of face. Rik's excellent image has captured a number of varieties of linear rilles including the Ariadaeus and Hyginus and their faint extensions and connections, and the very subtle Pau Rille (after master imager K.C. Pau who documented it) at top left of the image. But what really caught my attention was the fractured floor of Boscovich near the image center. There is a strong sense that the floor is domed, but is it? the LRO QuickMap provides a resounding yes answer. The east side of the central fracture line is strongly tilted upward about 220 meters and then drops 80 m or more. The drop on the south to north transect that passes through the triple junction of rilles is even more abrupt, perhaps 200 m in just about a 3 km horizontal distance. The north-south rille that crosses Boscovich has a very strong vertical offset - it is a fault as well as a rille.
Yesterday's LPOD: A Little History Peeking Out
Tomorrow's LPOD: Dome or Kipuka?