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Full-Text Articles in Physics

Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan Dec 2023

Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In solar–terrestrial physics, there is an open question: does a geomagnetic storm affect earthquakes? We expand research in this direction, analyzing the seismic situation after geomagnetic storms (GMs) accompanied by the precipitation of relativistic electrons from the outer radiation belt to form an additional radiation belt (RB) around lower geomagnetic lines. We consider four widely discussed cases in the literature for long-lived (weeks, months) RBs due to GMs and revealed that the 1/GMs 24 March 1991 with a new RB at L~2.6 was followed by an M7.0 earthquake in Alaska, 30 May 1991, near footprint L = 2.69; the 2/GMs …


Cluster Scaling And Critical Points: A Cautionary Tale, W. Klein, Harvey Gould, Sakib Matin Sep 2023

Cluster Scaling And Critical Points: A Cautionary Tale, W. Klein, Harvey Gould, Sakib Matin

Physics

Many systems in nature are conjectured to exist at a critical point, including the brain and earthquake faults. The primary reason for this conjecture is that the distribution of clusters (avalanches of firing neurons in the brain or regions of slip in earthquake faults) can be described by a power law. Because there are other mechanisms such as 1/f noise that can produce power laws, other criteria that the cluster critical exponents must satisfy can be used to conclude whether or not the observed power-law behavior indicates an underlying critical point rather than an alternate mechanism. We show how a …


Improving The Robustness Of The Advanced Ligo Detectors To Earthquakes, Eyal Schwartz, A. Pele, J. Warner, B. Lantz, Joseph Betzwieser, K. L. Dooley, S. Biscans, K. E. Ramirez Nov 2020

Improving The Robustness Of The Advanced Ligo Detectors To Earthquakes, Eyal Schwartz, A. Pele, J. Warner, B. Lantz, Joseph Betzwieser, K. L. Dooley, S. Biscans, K. E. Ramirez

Physics and Astronomy Faculty Publications and Presentations

Teleseismic, or distant, earthquakes regularly disrupt the operation of ground–based gravitational wave detectors such as Advanced LIGO. Here, we present EQ mode, a new global control scheme, consisting of an automated sequence of optimized control filters that reduces and coordinates the motion of the seismic isolation platforms during earthquakes. This, in turn, suppresses the differential motion of the interferometer arms with respect to one another, resulting in a reduction of DARM signal at frequencies below 100 mHz. Our method greatly improved the interferometers' capability to remain operational during earthquakes, with ground velocities up to 3.9 μm s−1 rms …


Strain Waves, Earthquakes, Slow Earthquakes, And Afterslip In The Framework Of The Frenkel-Kontorova Model, Naum I. Gershenzon, V. G. Bykov, Gust Bambakidis May 2009

Strain Waves, Earthquakes, Slow Earthquakes, And Afterslip In The Framework Of The Frenkel-Kontorova Model, Naum I. Gershenzon, V. G. Bykov, Gust Bambakidis

Physics Faculty Publications

The one-dimensional Frenkel-Kontorova (FK) model, well known from the theory of dislocations in crystal materials, is applied to the simulation of the process of nonelastic stress propagation along transform faults. Dynamic parameters of plate boundary earthquakes as well as slow earthquakes and afterslip are quantitatively described, including propagation velocity along the strike, plate boundary velocity during and after the strike, stress drop, displacement, extent of the rupture zone, and spatiotemporal distribution of stress and strain. The three fundamental speeds of plate movement, earthquake migration, and seismic waves are shown to be connected in framework of the continuum FK model. The …


Technical Risk Information: Decision Tool Or Rhetorical Ammunition? Undisputed Facts In The Yucca Mountain Debate, David M. Hassenzahl, Denise Tillery, Paulette Laidler Jan 2005

Technical Risk Information: Decision Tool Or Rhetorical Ammunition? Undisputed Facts In The Yucca Mountain Debate, David M. Hassenzahl, Denise Tillery, Paulette Laidler

Public Policy and Leadership Faculty Publications

This paper examines how both opponents and proponents of the proposed high-level nuclear waste repository at Yucca mountain Nevada claim that uncontroversial information supports their conflicting positions. Four pieces of information in particular are claimed by both sides: the distance of the proposed site from Las Vegas, the volume of waste that has been produced, the threat of terrorism since 9/11/01, and the occurrence of an earthquake in early 2002. Possible explanations for the difference include naive positivism, social constructionism, persistent beliefs and implicit warrants. The latter two models better explain observed knowledge/preference states. If so, more or better information …