172,116 research outputs found
Recommended from our members
The Making of Texas
This atlas presents plate reconstructions from the early Neoproterozoic (1000-750 Ma) to the present-day as derived by Ian Dalziel for the PLATES Project, Institute for Geophysics, The University of Texas at Austin.PLATES Project, Institute for Geophysics, The University of Texas at AustinInstitute for Geophysic
Celebrating the Physics in Geophysics
As 2005, the International Year of Physics, comes to an end, two physicists
working primarily in geophysical research reflect on how geophysics is not an
applied physics. Although geophysics has certainly benefited from progress in
physics and sometimes emulated the reductionist program of mainstream physics,
it has also educated the physics community about some of the generic behaviors
of strongly nonlinear systems. Dramatic examples are the insights we have
gained into the ``emergent'' phenomena of chaos, cascading instabilities,
turbulence, self-organization, fractal structure, power-law variability,
anomalous scaling, threshold dynamics, creep, fracture, and so on. In all of
these examples, relatively simple models have been able to explain the
recurring features of apparently very complex signals and fields. It appears
that the future of the intricate relation between physics and geophysics will
be as exciting as its past has been characterized by a mutual fascination.
Physics departments in our universities should capitalize on this trend to
attract and retain young talent motivated to address problems that really
matter for the future of the planet. A pressing topic with huge impact on
populations and that is challenging enough for both physics and geophysics
communities to work together like never before is the understanding and
prediction of extreme events.Comment: 6 pages, final version to appear in EOS-AGU Transactions in November
200
Exoplanetary Geophysics -- An Emerging Discipline
Thousands of extrasolar planets have been discovered, and it is clear that
the galactic planetary census draws on a diversity greatly exceeding that
exhibited by the solar system's planets. We review significant landmarks in the
chronology of extrasolar planet detection, and we give an overview of the
varied observational techniques that are brought to bear. We then discuss the
properties of the currently known distribution, using the mass-period diagram
as a guide to delineating hot Jupiters, eccentric giant planets, and a third,
highly populous, category that we term "ungiants", planets having masses less
than 30 Earth masses and orbital periods less than 100 days. We then move to a
discussion of the bulk compositions of the extrasolar planets. We discuss the
long-standing problem of radius anomalies among giant planets, as well as
issues posed by the unexpectedly large range in sizes observed for planets with
masses somewhat greater than Earth's. We discuss the use of transit
observations to probe the atmospheres of extrasolar planets; various
measurements taken during primary transit, secondary eclipse, and through the
full orbital period, can give clues to the atmospheric compositions,
structures, and meteorologies. The extrasolar planet catalog, along with the
details of our solar system and observations of star-forming regions and
protoplanetary disks, provide a backdrop for a discussion of planet formation
in which we review the elements of the favored pictures for how the terrestrial
and giant planets were assembled. We conclude by listing several research
questions that are relevant to the next ten years and beyond.Comment: Review chapter to appear in Treatise on Geophysics, 2nd Editio
Recommended from our members
SOAR (Support Office for Aerogeophysical Research) Annual Report 1994/1995
The Support Office for Aerogeophysical Research (SOAR) was a facility of the National Science Foundation's Office of Polar Programs whose mission is to make airborne geophysical observations available to the broad research community of geology, glaciology and other sciences. The central office of the SOAR facility is located in Austin, Texas within the University of Texas Institute for Geophysics. Other institutions with significant responsibilities are the Lamont Doherty Earth Observatory of Columbia University and the Geophysics Branch of the U.S . Geological Survey. This report summarizes the goals and accomplishments of the SOAR facility during 1994/1995 and plans for the next year.National Science Foundation's Office of Polar ProgramsInstitute for Geophysic
Geophysics and the great escape
In August 2011, the Centre for Battlefield Archaeology at the University of Glasgow undertook excavations at the prisoner of war camp of Stalag Luft III at Zagań, Poland. This was the site of the famous “Great Escape” in March 1944, when 76 officers escaped the camp through Harry, one of four tunnels dug by the prisoners during their incarceration. Of the escapers, 73 were recaptured and 50 of them were executed by the Gestapo, and the camp stands as a memorial to them. The tunnels are an important part of the memorial, testifying to the ingenuity and superhuman effort made by the prisoners in their attempt to escape and disrupt the German war machine
Small-World Networks in Geophysics
Many geophysical processes can be modelled by using interconnected networks.
The small-world network model has recently attracted much attention in physics
and applied sciences. In this paper, we try to use and modify the small-world
theory to model geophysical processes such as diffusion and transport in
disordered porous rocks. We develop an analytical approach as well as numerical
simulations to try to characterize the pollutant transport and percolation
properties of small-world networks. The analytical expression of system
saturation time and fractal dimension of small-world networks are given and
thus compared with numerical simulations
Recommended from our members
SOAR (Support Office for Aerogeophysical Research) Annual Report 1995/1996
The Support Office for Aerogeophysical Research (SOAR) was a facility of the National Science Foundation's Office of Polar Programs whose mission is to make airborne geophysical observations available to the broad research community of geology, glaciology and other sciences. The central office of the SOAR facility is located in Austin, Texas within the University of Texas Institute for Geophysics. Other institutions with significant responsibilities are the Lamont Doherty Earth Observatory of Columbia University and the Geophysics Branch of the U.S . Geological Survey. This report summarizes the goals and accomplishments of the SOAR facility during 1995/1996 and plans for the next year.National Science Foundation's Office of Polar ProgramsInstitute for Geophysic
Information Theory and the Earth's Density Distribution
An argument for using the information theory approach as an inference technique in solid earth geophysics. A spherically symmetric density distribution is derived as an example of the method. A simple model of the earth plus knowledge of its mass and moment of inertia lead to a density distribution which was surprisingly close to the optimum distribution. Future directions for the information theory approach in solid earth geophysics as well as its strengths and weaknesses are discussed
Computer programs perform spectral analyses of up to seven time series
Computer programs perform statistical spectral analyses of up to seven time series. These programs should have applicability to a variety of engineering systems in the fields of geophysics, physiology, acoustics, and structural analysis
- …