As Mercury orbits the Sun, solar induced gravitational torques give rise to a planetary libration. While undergoing this 88 day period libration, the axes of minimum moment of inertia of the mantle and solid core, if present, become misaligned, leading to a gravitational torque which initiates a free-mode of axial oscillation between the inner core and mantle. For a large gravitational torque, the free-mode period approaches the period of the libration forcing, and should participate in the planets libration response. The goal of this work is to determine whether Mercurys observed librations can be used to place constraints on the inner core structure. Perturbations in Mercurys rotation rate are simulated for a range of interior structures. For models where the free-mode interferes with the libration signature, a marginally better fit between model response and observations is obtained, compared to models which exhibit the libration signature alone. / Geophysics
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1521 |
| Date | 11 1900 |
| Creators | Veasey, Martin James |
| Contributors | Dumberry, Mathieu (Physics), Sutherland, Bruce (Physics and Earth and Atmospheric Sciences), Heimpel, Moritz (Physics), Kavanaugh, Jeffrey (Earth and Atmospheric Sciences) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 11219219 bytes, application/pdf |
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