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On the Origin of Gravity and Topography Anomalies of the Tharsis Rise on Mars
| Content Provider | Semantic Scholar |
|---|---|
| Author | Zhong, S. J. |
| Copyright Year | 2002 |
| Abstract | The Tharsis rise displays the most significant long-wavelength gravity and topography anomalies on Mars [1,2] and it is characterized by successive and concentrated tectonic activity and volcanism that spans Noachian to Amazonian [3]. Understanding the origin of gravity and topography anomalies of the Tharsis rise has important implications for studies of Martian tectonics, volcanism, and long-term thermal evolution [4]. Two competing models have been proposed to explain the origin of the topography and geoid anomalies for the Tharsis. In the first model the Tharsis rise is attributed to loading of volcanic construction on lithosphere [5], while in the second model the elevated topography and geoid of the Tharsis are explained as dynamic effects of one-plume thermal structure below the Tharsis [6,7]. In this study we seek to distinguish between these two models by formulating a generalized viscoelastic (VE) loading model that determines responses (i.e., deflection at the surface and CMB and the geoid) to loads at different depths. With this new formulation, we found that the instantaneous viscous flow (IVF) loading formulation used in [7] may significantly overestimate the geoid from the plume because the elastic effects of lithosphere are ignored. We suggest that the one-plume structure if currently existing below the Tharsis may only be responsible for a small fraction (~10%) of the Tharsis geoid provided that elastic thickness is ~150 km or larger [8]. This suggests that other processes including surface loading of volcanic construction may be the primary cause of the geoid. This may also put a constraint on how much the elevated topography of the Tharsis rise can be attributed to plume buoyancy. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.lpi.usra.edu/meetings/lpsc2002/pdf/1812.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
