Crustal Deformation due to Atmospheric Pressure Loading in New Zealand

Crustal Deformation due to Atmospheric Pressure Loading in New ZealandWe investigate atmospheric pressure loading displacements in New Zealand using global and regional air-pressure data collected over a period of 50 years (1960-2009). The elastic response of the Earth to atmospheric loading is calculated by adopting mass loading Love numbers based on the parameters of the Preliminary Reference Earth Model (PREM). The ocean response to atmospheric loading is computed utilising a modified inverted barometer theory. The results reveal that the atmospheric loading vertical displacements are typically smallest along coastal regions, while gradually increasing inland with the maximum peak-to-peak displacement of 13.1 mm for this study period. In contrast, the largest horizontal displacements are found along coastal regions, where the maximum peak-to-peak displacement reaches 2.7 mm. The vertical displacements have a high spatial correlation, whereas the spatial correlation of the horizontal displacement components is much smaller. A spectral decomposition of the atmospheric loading time series shows that the signal is a broad band with most energy between 1 week and annual periods, and with a couple of peaks corresponding to approximately annual forcing and its overtones. The largest amplitudes in the atmospheric loading time series have an annual and semi-annual period.

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Analysis of Time Series of GPS Height Estimates with Regard to Atmospheric Pressure Loading

International Association of Geodesy Symposia - Vertical Reference Systems ◽

10.1007/978-3-662-04683-8_19 ◽

2002 ◽

pp. 97-100

Author(s):

Petra Häfele ◽

Klaus Kaniuth

Keyword(s):

Time Series ◽

Atmospheric Pressure ◽

Pressure Loading ◽

Height Estimates ◽

Atmospheric Pressure Loading ◽

Analysis Of Time Series

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Identifying the sensitivity of GPS to non-tidal loadings at various time resolutions: examining vertical displacements from continental Eurasia

GPS Solutions ◽

10.1007/s10291-021-01135-w ◽

2021 ◽

Vol 25 (3) ◽

Author(s):

Anna Klos ◽

Henryk Dobslaw ◽

Robert Dill ◽

Janusz Bogusz

Keyword(s):

Time Series ◽

Seasonal Changes ◽

System Modeling ◽

Sea Level Changes ◽

Observation Level ◽

Earth System Modeling ◽

Atmospheric Loading ◽

Modeling Group ◽

Vertical Displacements ◽

Almost All

AbstractWe examine the sensitivity of the Global Positioning System (GPS) to non-tidal loading for a set of continental Eurasia permanent stations. We utilized daily vertical displacements available from the Nevada Geodetic Laboratory (NGL) at stations located at least 100 km away from the coast. Loading-induced predictions of displacements of earth’s crust are provided by the Earth-System-Modeling Group of the GFZ (ESMGFZ). We demonstrate that the hydrological loading, supported by barystatic sea-level changes to close the global mass budget (HYDL + SLEL), contributes to GPS displacements only in the seasonal band. Non-tidal atmospheric loading, supported by non-tidal oceanic loading (NTAL + NTOL), correlates positively with GPS displacements for almost all time resolutions, including non-seasonal changes from 2 days to 5 months, which are often considered as noise, intra-seasonal and seasonal changes with periods between 4 months and 1.4 years, and, also, inter-annual signals between 1.1 and 3.0 years. Correcting the GPS vertical displacements by NTAL leads to a reduction in the time series variances, evoking a whitening of the GPS stochastic character and a decrease in the standard deviation of noise. Both lead, on average, to an improvement in the uncertainty of the GPS vertical velocity by a factor of 2. To reduce its impact on the GPS displacement time series, we recommend that NTAL is applied at the observation level during the processing of GPS observations. HYDL might be corrected at the observation level or remain in the data and be applied at the stage of time series analysis.

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