Journal ArticleDOI
The impulse response of a Maxwell Earth
TLDR
In this paper, an extended form of the correspondence principle is employed to determine directly the quasi-static deformation of viscoelastic earth models by mass loads applied to the surface.Abstract:
An extended form of the correspondence principle is employed to determine directly the quasi-static deformation of viscoelastic earth models by mass loads applied to the surface. The stress-strain relation employed is that appropriate to a Maxwell medium. Most emphasis is placed on the discussion of spherically stratified self-gravitating earth models, although some consideration is given to the uniform elastic half space and to the uniform viscous sphere, since they determine certain limiting behaviors that are useful for interpretation and proper normalization of the general problem. Laplace transform domain solutions are obtained in the form of ‘s spectra’ of a set of viscoelastic Love numbers. These Love numbers are defined in analogy with the equivalent elastic problem. An efficient technique is described for the inversion of these s spectra, and this technique is employed to produce sets of time dependent Love numbers for a series of illustrative earth models. These sets of time dependent Love numbers are combined to produce Green functions for the surface mass load boundary value problem. Through these impulse response functions, which are obtained for radial displacement, gravity anomaly, and tilt, a brief discussion is given of the approach to isostatic equilibrium. The response of the earth to an arbitrary quasi-static surface loading may be determined by evaluating a space-time convolution integral over the loaded region using these response functions.read more
Citations
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GLOBAL GLACIAL ISOSTASY AND THE SURFACE OF THE ICE-AGE EARTH: The ICE-5G (VM2) Model and GRACE
TL;DR: The impact of the changing surface ice load upon both Earth's shape and gravitational field, as well as upon sea-level history, have come to be measurable using a variety of geological and geophysical techniques.
Journal ArticleDOI
Sea Level Change Through the Last Glacial Cycle
Kurt Lambeck,John Chappell +1 more
TL;DR: For example, in this paper, the authors show that the earth-response function is depth dependent as well as spatially variable, and that the migration of coastlines can be predicted during glacial cycles, including the anthropologically important period from about 60,000 to 20,000 years ago.
Journal ArticleDOI
Sea level and global ice volumes from the Last Glacial Maximum to the Holocene.
TL;DR: From ∼1,000 observations of sea level, allowing for isostatic and tectonic contributions, this work quantified the rise and fall in global ocean and ice volumes for the past 35,000 years and provides new constraints on the fluctuation of ice volume in this interval.
Journal ArticleDOI
Ice Age Paleotopography
TL;DR: The results show that LGM ice volume was approximately 35 percent lower than suggested by the CLIMAP reconstruction and the maximum heights of the main Laurentian and Fennoscandian ice complexes are inferred to have been commensurately lower with respect to sea level.
References
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Journal ArticleDOI
Late Quaternary Vertical Movements in Eastern North America: Quantitative Evidence of Glacio-Isostatic Rebound
TL;DR: In this paper, a review collects the evidence of vertical movements in northern and eastern North America from different sources and disciplines to provide in one publication the quantitative data important for geophysical analyses of glacio-isostatic rebound.
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Viscosity of the mantle from relaxation time spectra of isostatic adjustment
TL;DR: In this article, harmonic analysis of the present level of former shoreline features in southeast Fennoscandia indicates that shorter wavelength departures from equilibrium relax more rapidly than longer ones, indicating that flow in the upper-mantle low-viscosity channel as a result of the Pleistocene glacial loading is the most likely source of the earth's nonhydrostatic bulge.
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Experimental isostasy: 1. Theory of the determination of the Earth's isostatic response to a concentrated load
TL;DR: In this paper, a method for the computation of the isostatic response function directly from observational data, eliminating the need for assuming a compensation mechanism, was presented, where the earth is linear in its response to the crustal loading of the topography, and the response of the earth's gravity field to this loading can be represented as the two-dimensional convolution of the surface topography with the Earth's isostastic response function.
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A Green's function for determining the deformation of the Earth under surface mass loads: 2. Computations and numerical results
TL;DR: In this article, the surface deformation and perturbation in the superficial gravity field of the earth are presented for the Gutenberg earth model, which is assumed to be subjected to surface mass loading.
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Dynamical Models for Sea Floor Spreading
TL;DR: In this paper, the authors investigate the role of vertical temperature gradients and find these incapable of generating flows in the asthenosphere that move overlying lithospheric plates by viscous traction.