P41C-2082
The Deep Lunar Interior with a Low-Viscosity Zone: Revised Constraints from Recent Geodetic Parameters on the Tidal Response of the Moon
Thursday, 17 December 2015
Poster Hall (Moscone South)
Yuji Harada1, Sander J Goossens2, Koji Matsumoto3, Jianguo Yan4, Jinsong Ping5, Hirotomo Noda3 and Junichi Haruyama6, (1)Macau University of Science and Technology, Taipa, China, (2)University of Maryland, Baltimore County, Baltimore, United States, (3)National Astronomical Observatory of Japan, Oshu, Japan, (4)Wuhan University, Wuhan, China, (5)National Astronomical Observatories, Beijing, China, (6)Institute of Space and Aeronautical Science, Sagamihara, Japan
Abstract:
We revisit the constraints from our earlier investigation on the deep lunar interior with a possible low-viscosity layer by describing the Moon's tidal response. In here we consider several tidal parameters that have been improved or are newly determined from recent geodetic observations and analyses. First, providing the internal structure of the Moon, especially its viscosity profile, we compute its tidal quality factors (i.e., Q) and Love numbers (i.e., k2, k3, and h2) for the monthly, annual, triennial, and sexennial tidal periods. Second, we compare these theoretical values with observational ones. As a result of this comparison, we can find a viscosity profile with the low-viscosity zone which is consistent with the frequency-dependent quality factors although its viscosity range is slightly larger than that constrained previously. In addition, we can completely or nearly explain each Love number by considering the above constraint on the viscosity range revised here, at least limited to the monthly tide. Finally, we conclude that this layer reaches just below or inside the place where many seismic nests of deep moonquakes are located.
