Author ORCID Identifier

https://orcid.org/0000-0001-6398-9723

Year of Publication

2021

Degree Name

Master of Science (MS)

Document Type

Master's Thesis

College

Arts and Sciences

Department/School/Program

Earth and Environmental Sciences (Geology)

First Advisor

Dr. Dhananjay Ravat

Abstract

We use a Bouguer mass-sheet approximation for spectral admittance and correlation modeling to estimate elastic thickness, crustal thickness, crustal density, and load density across the Mars crustal dichotomy boundary near the landing site of NASA’s InSight Lander. We derive and constrain the parameter ranges using RMS misfit between the observed and theoretical admittance and their error bars. Spherical cap windows of 15° (900 km) radius are used to study 15 locations in the Northern Lowlands, the Southern Highlands and near and on the boundary which suggest distinct, but not sharp, difference in lithospheric properties. Elastic thickness estimates range generally between 0 and 30km in the Northern Lowlands, between 0 and 50km in the South Highlands and between 0 and 40km on the boundary itself. Crustal density varies from generally 2300-2900kgm-3 in the Northern Lowlands to 2200-2500kgm-3 in the Southern Highlands with intermediate values of 2200-2600kgm-3 directly on the boundary. It was not possible to adequately constrain well the surface (load) density for any of regions studied. No elastic thickness estimates for this region were thicker than 50km and the elastic thickness was always smaller than the crustal thickness. This region of the Northern Lowlands could have originally had similar elastic thickness as the neighboring Southern Highlands, and the large impacts that re-molded the northern hemisphere into the Northern Lowlands may have also increased the crustal density and reduced elastic thickness. In a couple of locations on the Highlands, however, the elastic thickness is small and these parts could have been weakened by local tectono-thermal processes after the formation of the boundary.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2021.331

Share

COinS