open access

https://hdl.handle.net/2115/95693

Interference of ocean and land mass changes in seasonal crustal deformation of coastal stations: A case study in northern Australia

英語

Australia

2023-07-15

Elsevier

Earth and Planetary Science Letters

614

118212

In tropical regions, alternation of rainy and dry seasons causes significant land hydrological mass changes. It brings “landward” seasonal crustal movements of coastal global navigation satellite system (GNSS) stations in rainy seasons. Here, we report that the coastal region of the Gulf of Carpentaria (GOC), northern Australia, behaves oppositely, i.e., they move “oceanward” during austral summer months despite large precipitations on land. Here we study seasonal gravity changes there with satellite gravimetry and analyze seasonal movements of GNSS stations in that region. During the austral summer, hydrological mass increases in nearby land areas. In addition to that, sea water mass within the gulf also increases due to east-southeastward seasonal winds. It has larger amplitudes than on land, and its peak comes a few months earlier, resulting in seasonal displacements of coastal GNSS stations driven predominantly by ocean mass changes. In this study, we emphasize the importance of seasonal horizontal crustal movements, i.e., the oceanward displacements of coastal stations there in austral summer clearly indicate the dominance of the excessive ocean mass over those on land. Such seasonal mass changes within GOC have been largely overlooked because of insufficient spatial resolution of satellite gravimetry. This study presents a model case for interpreting complicated seasonal surface deformation caused by significant seasonal load changes on land and ocean, often found in coastal areas of half-closed oceans in the world.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

©2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

0012-821X

AA00631029