1,090 research outputs found
The Interpretation of gravity changes and crustal deformation in active volcanic areas
No full textSimple models, like the well-known point source of dilation (Mogi’s source) in an elastic,
homogeneous and isotropic half-space, are widely used to interpret geodetic and gravity data in active
volcanic areas. This approach appears at odds with the real geology of volcanic regions, since the crust is
not a homogeneous medium and magma chambers are not spheres. In this paper, we evaluate several more
realistic source models that take into account the influence of self-gravitation effects, vertical
discontinuities in the Earth’s density and elastic parameters, and non-spherical source geometries. Our
results indicate that self-gravitation effects are second order over the distance and time scales normally
associated with volcano monitoring. For an elastic model appropriate to Long Valley caldera, we find only
minor differences between modeling the 1982–1999 caldera unrest using a point source in elastic,
homogeneous half-spaces, or in elasto-gravitational, layered half-spaces. A simple experiment of matching
deformation and gravity data from an ellipsoidal source using a spherical source shows that the standard
approach of fitting a center of dilation to gravity and uplift data only, excluding the horizontal
displacements, may yield estimates of the source parameters that are not reliable. The spherical source
successfully fits the uplift and gravity changes, overestimating the depth and density of the intrusion, but is
not able to fit the radial displacements
Constraining the Source of Unrest at Campi Flegrei (Italy) Using Geodetic And Micro-Gravity Data.
No full textOptimal control of noisy finite-state Markov processes
No full textBibliography: leaf 32.Dept. of Defense Contract Nr N00014-75-C-1183 and NSF Grant ENG75-14103.Adrian Segall
A reliable broadcast algorithm
No full textBibliography: p. 19."January 1982""ONR-N00014-77-C-0532" "N00014-75-C-1183"Adrian Segall, Baruch Awerbuch
An optimal approach to dynamic routing in networks : Part II--a maximal flow approach
No full text"June, 1981."Bibliography: p. 20.U.S. Dept. of Defense contract No. N00014-75-C-1183Mario Jodorkovsky and Adrian Segall
Two interfering queues in packet-radio networks
No full textBibliography: p. 14."June, 1981."U.S. Department of Defense contract No. N00014-75-C-1183M. Sidi and A. Segall
A busy-tone-multiple-access-type scheme for packet-radio networks
No full textBibliography: p. 17."June, 1981."Office of Naval Research contract No. ONR/N00014-77-C-0532Moshe Sidi and Adrian Segall
Optimal distributed routing for virtual line-switched data networks
No full textBibliography: p. 35."September 1978."Supported by the Advanced Research Project Agency (monitored by ONR) under Contract no. N00014-75-C-1183Adrian Segall
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