- Title
- Surface mass variation on the solid earth inferred from GPS deformation time series and GRACE gravity field measurements
- Creator
- Razeghi, Seyedeh Mahdiyeh
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2020
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Deformation time series from GPS and gravity field change observations by the GRACE satellite mission, used either as validation or in combination, have been deployed to quantify the Earth’s elastic and viscous responses to different kinds of surface mass loading. These two data sets can complement each other to study the surface mass variations, when they are made consistent in terms of spatial resolution, temporal resolution and their reference frames. This study explored the Slepian localization method to make two distinct geodetic data sets consistent in terms of spatial and spectral resolutions. This method also made it possible to determine regional surface mass change in Australia merely by GPS deformation data. The monthly surface mass variation not only agreed with other independent datasets, such as GRACE, the atmospheric model, and the hydrology model, but also presented significant sub-monthly changes throughout the area of the study. In terms of the reference frame, a new technique was developed to co-estimate geocentre motion and the gravitational potential field from global observations of the GPS and GRACE. Geocentre motions resulting from this new approach were mostly consistent with the SLR degree-1 solutions indicating an overall seasonal migration pattern from Europe to the South Pacific Ocean of the degree-1 surface mass load. In addition to estimating the Earth’s elastic responses, these two geodetic data sets can also be employed for estimating the Earth’s viscous responses, which are associated to GIA. A high-resolution ice mass model of the Totten Glacier’s outlet was constructed, which follows altimetry measurements in terms of spatial resolution, and GRACE gravity data in terms of temporal resolution, to calculate the elastic deformation over the area. The GIA uplift rate was computed by removing anticipated elastic responses from the GPS vertical time series, and then the residual deformation was considered to be the viscos deformation and compared to various GIA models. It is also found that removal of the predicted elastic deformation from the east and north components of GPS tie series resulted in a steady-state trend relevant to kinematic plate motions.
- Subject
- GPS; GRACE; gravity field; displacement; deformation; GIA; thesis by publication
- Identifier
- http://hdl.handle.net/1959.13/1412540
- Identifier
- uon:36497
- Rights
- Copyright 2020 Seyedeh Mahdiyeh Razeghi
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 20 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 387 KB | Adobe Acrobat PDF | View Details Download |