Dissertation/Thesis Abstract

Layered Cartesian Half-Space Models for Earth's Elastic Response to Contemporary Surface Loading Phenomena
by Zhou, Hao, Ph.D., The Ohio State University, 2008, 178; 10631419
Abstract (Summary)

Postglacial rebound (PGR) represents a complicated interplay of the solid Earth and ice history, through which scientists can investigate past climate changes. During the past decades, the advancement of spatial technology significantly enhanced scientists' capability to observe PGR signals. However, in many glacial regions of the world, PGR signals are 'contaminated' by vertical elastic crustal deformation, which is induced by present ice mass change.

In order to estimate the magnitude and pattern of the elastic crustal deformation, a layered elastic loading model has been developed in this dissertation work. It is capable of computing surface deformation due to an arbitrary shape load. The high-speed computing capability of this model provides us possibilities to investigate elastic properties of the Earth's crust in detail.

This elastic loading model is applied to the Patagonia ice field to eliminate elastic rebound signal due to present ice loss. Using different combinations of ice loss models and Earth's elastic structures, we estimated that the present ice loss contributes 5-25% to the total crustal uplift. In addition, we used geodetic measurements to further confirm that the broad pattern of uplift in the Patagonia region reflects the Earth's response to the deglaciation of the Little Ice Age (LIA) rather than that of the Last Glacial Maximum (LGM), due to the unique tectonic setting of this region.

The Inverse Bousinessq Response (IBR) effect observed by the strainmeters in California is also explained by numerical modeling using the layered elastic loading model. High Poisson's ratio and strong stiffness contrast of the crust's soft and hard sediment layers play an important role in the IBR's occurrence. The thickness of the soft sediment layer controls the location and spatial extent of the IBR effect.

In Greenland, we used the elastic loading model and the most complete estimate of ice mass change (1993 - 2000) to demonstrate that by using continuous GPS measurements, we can detect and assess ice loss acceleration in Greenland faster than by using other geodetic tools.

Indexing (document details)
Advisor: Bevis, Mike
School: The Ohio State University
Department: Geological Sciences
School Location: United States -- Ohio
Source: DAI-B 78/11(E), Dissertation Abstracts International
Subjects: Geology, Geophysics
Keywords: Bousinessq, Crust, Elastic loading, Pgr
Publication Number: 10631419
ISBN: 978-0-355-01659-8
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