BibSonomyburst/user/andreab/EarthBibSonomy RSS feed for /user/andreab/Earth2012-02-16T07:47:30+01:00http://www.bibsonomy.org/bibtex/2dfa6ab3223f72b2c1fd073e3fa999739/andreabandreab2007-10-18T11:58:42+02:00earth geophysics imported model mountains topography <span class="authorEditorList"><a href="/author/Willett">S. D. Willett</a>, <a href="/author/Slingerland">R. Slingerland</a>, and <a href="/author/Hovius">N. Hovius</a> </span>(<em>2001</em>)Thu Oct 18 11:58:42 CEST 2007American Journal of Science455-485Uplift shortening and steady-state topography in active mountain belts3012001earth geophysics imported model mountains topography ABSTRACT. We present a tectonic, surface process model used to investigate the role of horizontal shortening in convergent orogens and the effects on steady-state topography. The tectonic model consists of a specified velocity field for the Earth’s surface and includes a constant uplift rate and a constant horizontal strain rate which varies to reflect the relative importance of frontal accretion and underplating in an orogenic wedge. The surface process model includes incision of a network of rivers formed by collection of applied precipitation and diffusive hillslope mass transfer. Three non-dimensional parameters describe this model: a ratio of the maximum horizontal velocity to the vertical velocity, a Peclet number expressing the efficiency of the hillslope diffusion relative to the uplift rate, and a fluvial “erosion number” reflecting the fluvial incision efficiency relative to the uplift rate. A series of models are presented demonstrating the resultant steady-state landforms parameterized by these three numbers. A finite velocity ratio results in an asymmetric form to the model mountain range, although the magnitude of the asymmetry also depends on the Peclet number. Topographic steady-state is achieved faster for models with no horizontal component to the velocity field. With finite horizontal velocity, topographic steady state is achieved only at the scale of the entire mountain range; even the first order drainage basins are unstable with time in the presence of horizontal shortening. We compare our model results to topographic profiles from active mountain ranges in Taiwan, New Zealand, and the Olympic Mountains of Washington state. All these examples exhibit asymmetric topographic form with the asymmetry consistent with the polarity of subduction, suggesting that horizontal tectonic motion is affecting the macro-geomorphic form of these ranges. Earth Surface Processes Publicationshttp://www.bibsonomy.org/bibtex/2fd912f4b3fab79c7f110f792c644473c/andreabandreab2007-10-18T11:51:46+02:00Earth Mars coastal coastlines geophysics <span class="authorEditorList"><a href="/author/Parker">Timothy J. Parker</a>, and <a href="/author/Currey">Donald R. Currey</a> </span><em>Geomorphology</em> <em>37(3-4):303--328</em> (<em>April 2001</em>)Thu Oct 18 11:51:46 CEST 2007Geomorphology#apr#3-4303--328Extraterrestrial coastal geomorphology372001Earth Mars coastal coastlines geophysics Earth is the only planet in the solar system where large amounts of liquid water have been stable at the surface throughout geologic time. This unique trait has resulted in the production of characteristic landforms and massive accumulations of aqueous sediments, as well as enabled the evolution of advanced and diverse forms of life. But while Earth is the only planet with large bodies of water on its surface today, Venus and Mars may have once had lakes or oceans as well. More exotic fluids may be stable in the outer solar system. Prior to the Voyager flybys of the outer planets during the 1970s and 1980s, the moon of Neptune, Triton, was thought to be much larger than the Voyager cameras revealed it to be, and predictions that liquid nitrogen lakes or oceans might be found were made. The moon of Saturn, Titan, however, was found to have a massive atmosphere, so the possibility remains that it may have, or may once have had, lakes or oceans of liquid hydrocarbons. The recent, high-resolution synthetic aperture radar imaging of Venus has failed to reveal any evidence of any putative clement period, but the results for Mars are much more intriguing. Herein, we briefly review work on this subject by a number of investigators, and discuss problems of identifying and recognizing martian landforms as lacustrine or marine. In addition, we present additional examples of possible martian coastal landforms. The former presence of lakes or oceans on Mars has profound implications with regard to the climate history of that planet.http://www.bibsonomy.org/bibtex/205edcf21b57ebc1e88e0f5207cb8f612/andreabandreab2007-02-06T12:23:50+01:00earth fractal scaling geomorphology 2000 rivernetworks imported review <span class="authorEditorList"><a href="/author/Dodds">Peter Sheridan Dodds</a>, and <a href="/author/Rothman">Daniel H. Rothman</a> </span><em>Annual Review of Earth and Planetary Sciences</em> <em>28(1):571-610</em> (<em>2000</em>)Tue Feb 06 12:23:50 CET 2007Annual Review of Earth and Planetary Sciences1571-610Scaling, Universality, and Geomorphology282000earth fractal scaling geomorphology 2000 rivernetworks imported review Theories of scaling apply wherever similarity exists across many scales. This similarity may be found in geometry and in dynamical processes. Uni- versality arises when the qualitative character of a system is sufficient to quantitatively predict its essential features, such as the exponents that characterize scaling laws. Within geomorphology, two areas where the concepts of scaling and universality have found application are the geometry of river networks and the statistical structure of topography. We begin this review with a pedagogical presentation of scaling and universality. We then describe recent progress made in applying these ideas to net- works and topography. This overview leads to a synthesis that attempts a classification of surface and network properties based on generic mechanisms and geometric con- straints. We also briefly review how scaling and universality have been applied to related problems in sedimentology—specifically, the origin of stromatolites and the relation of the statistical properties of submarine-canyon topography to the size dis- tribution of turbidite deposits. Throughout the review, our intention is to elucidate not only the problems that can be solved using these concepts, but also those that cannot.