University of Tasmania
Browse
137483 - Present-day vertical land motion of Australia from GPS observations.pdf (1.17 MB)

Present‐day vertical land motion of Australia from GPS observations and geophysical models

Download (1.17 MB)
journal contribution
posted on 2023-05-20, 11:00 authored by Anna RiddellAnna Riddell, Matt KingMatt King, Christopher WatsonChristopher Watson
The secular rate of Australia's vertical surface deformation due to past ice‐ocean loading changes is not consistent with present vertical velocities observed by a previously sparse network of Global Positioning System (GPS) sites. Current understanding of the Earth's rheology suggests that the expected vertical motion of the crust should be close to zero given that Australia is located in the far field of past ice sheet loading. Recent GPS measurements suggest that the vertical motion of the Australian continent at permanent sites is between 0 and −2 mm/year. Here we investigate if vertical deformation due to previous ice sheet loading can be recovered in the time series of Australian GPS sites through enlarging the number of sites compared to previous studies from ~20 to more than 100 and through the application of improved data filtering. We apply forward geophysical models of elastic surface displacement induced by atmospheric, hydrologic, nontidal ocean, and ice loading and use independent component analysis as a spatiotemporal filter that includes multivariate regression to consider temporally correlated noise in GPS. Using this approach, the common mode error is identified, and subsequent multivariate regression leads to an average reduction in trend uncertainty of ~35%. The average vertical subsidence of the Australian continent is substantially different to vertical motion predicted by glacial isostatic adjustment and surface mass transport models.

History

Publication title

JGR Solid Earth

Volume

125

Article number

e2019JB018034

Number

e2019JB018034

Pagination

1-17

ISSN

2169-9313

Department/School

School of Geography, Planning and Spatial Sciences

Publisher

Wiley-Blackwell Publishing Inc.

Place of publication

United States

Rights statement

Copyright 2020 Geoscience Australia, Commonwealth of Australia. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Expanding knowledge in the earth sciences

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC