Co-location of the downdip end of seismic locking and the continental shelf break

Author(s):  
Luca C. Malatesta ◽  
Lucile Bruhat ◽  
Noah J. Finnegan ◽  
Jean-Arthur L. Olive

<p>Along subduction margins, the morphology of the near shore domain records the combined action of erosion from ocean waves and permanent tectonic deformation from the convergence of plates. We observe that at subduction margins around the globe, the edge of continental shelves tends to be located above the downdip end of seismic coupling on the megathrust (locking depth). Coastlines lie farther landward at variable distances. This observation stems from a compilation of well-resolved coseismic and interseismic<span>  </span>coupling datasets. The permanent interseismic uplift component of the total tectonic deformation can explain the localization of the shelf break. It contributes a short wave-length gradient in vertical deformation on top of the structural and isostatic deformation of the margin. This places a hinge line between seaward subsidence and landward uplift above the locking depth. Landward of the hinge line, rocks are uplifted in the domain of wave-base erosion and a shelf is maintained by the competition of rock uplift and wave erosion. Wave erosion then sets the coastline back from the tectonically meaningful shelf break. We combine a wave erosion model with an elastic deformation model to show how the locking depth pins the location of the shelf break. In areas where the shelf is wide, onshore geodetic constraints on seismic coupling is limited and could be advantageously complemented by considering the location of the shelf break. Subduction margin morphology integrates hundreds of seismic cycles and could inform seismic coupling stability through time.</p>

The purpose of this paper is to discuss the absorption of light by non-metallic solids, and in particular the mechanism by which the energy of the light absorbed is converted into heat. If one considers from the theoretical point of view the absorption spectrum of an insulation crystal, one finds that it consists of a series of sharp lines leading up to a series limit, to the short wave-length side of which true continuous absorption sets in (Peierls 1932; Mott 1938). In practice the lattice vibrations will broaden the lines to a greater of less extent. When a quantum of radiation is absorbed in the region of true continuous absorption, a free electron in the conduction band and a "positive hole" are formed with enough energy to move away from one another and to take part in a photocurrent within the crystal. When, however, a quantum is absorbed in one of the absorption lines , the positive hole and electron formed do not have enough energy to separate, but move in one another's field in a quantized state. An electron in a crystal moving in the field of a positive hole has been termed by Frenkel (1936) an "exciton".


Our knowledge concerning the state of the atmosphere lying above about 80 km. in height has been derived from experiments on radio wave reflexion as well as from studies of terrestrial magnetism and of the aurora. The information derived from radio experiments is, fortunately, in the nature of a supplement to, rather than a duplicate of, information derivable in other ways. As one of the best examples in this connexion may be mentioned the question of electrical conductivity. Here the magnetic studies of Schuster and Chapman yield an estimate of the total conductivity for currents travelling horizontally, whereas the radio measurements give the state of ionization at different levels from which the specific conductivity at those levels may be estimated. One of the most striking things about the ionosphere is the marked solar control. Speaking generally it may be said that the ionization increases and decreases as the sun rises and sets. Again, speaking generally, we may say that the main part of the ionization is caused by solar-violet light. The rays from the sun meet the outer layers of the atmosphere first and the short wave-length radiation is absorbed there, causing ionization. It thus comes about that the study of the ionosphere becomes the study of an interesting part of the sun's spectrum which cannot be detected at ground level. It also becomes the study of certain atomic processes such as photo-ionization, recombination of ions and attachment of electrons to neutral molecules such as cannot be investigated at very low pressure in the laboratory, because of the influence of the walls of the vessel confining the gas.


2007 ◽  
Vol 4 (3) ◽  
pp. 387-392
Author(s):  
Baghdad Science Journal

The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.72) at the same thickness & concentration of the sample.


2017 ◽  
Vol 59 (8-9) ◽  
pp. 763-771 ◽  
Author(s):  
G. M. Bubnov ◽  
Yu. N. Artemenko ◽  
V. F. Vdovin ◽  
D. B. Danilevsky ◽  
I. I. Zinchenko ◽  
...  

1963 ◽  
Vol 18 (7) ◽  
pp. 557-562 ◽  
Author(s):  
Rainer Bergfeld

Morphogenesis and differentiation of fern gametophytes (Dryopteris filix-mas) are strongly controlled by light. “Normal” morphogenesis, i. e. formation of two- or three dimensional prothallia, can occur only under short wave length visible light (= blue light). In darkness and under long wave length visible light (= red light) the gametophytes will grow as filaments. The blue light dependent photoreactive system which controls morphogenesis seems to be located in the outer layers of the cytoplasm. The control of morphogenesis is causally connected with the increase of protein synthesis under the influence of blue light.In the present paper the influence of red and blue light on shape and volume of the nucleus in the fully grown basal cell of the young gametophyte of Dryopteris filix-mas has been investigated. In blue light the nuclei are more or less spherical, in red and in darkness they are spindle shaped. If the light quality is changed the shape of the nuclei is only slightly influenced; the nuclear volume, however, is drastically changed: increase of volume in the blue, decrease of nuclear volume in red and darkness. These reversible changes of nuclear volume under the influence of light, which are apparently correlated with changing rates of protein synthesis, are an impressive example for the control of nuclear properties by an external factor via the cytoplasm.


1960 ◽  
Vol 6 (1) ◽  
pp. 31-34
Author(s):  
Shoichi Ishikawa ◽  
Jiro Shimizu

1960 ◽  
Vol 10 ◽  
pp. 706-708 ◽  
Author(s):  
Herbert Friedman

The X-ray spectrum of a quiet Sun can be approximated by a 500,000° K Planckian distribution. In the absence of coronal excitation, as evidenced by the intensity of the Fe xiv green line, the X-ray spectrum has a short wave-length limit near 20 A. Coronal activity is accompanied by weak emissions down to wave-lengths as short as 6 A, which appear to be associated with coronal hot spots at temperatures of 2 x 106° K or higher.


1977 ◽  
Vol 43 ◽  
pp. 45-45
Author(s):  
F. Bely-Dubau ◽  
A.H. Gabriel ◽  
S. Volontè

New calculations have been carried out in intermediate coupling of the wavelengths and intensities of the Fe XXIV transitions ls2nℓ-ls2pnℓ with n ≥ 3.It is shown that some of these lines are situated on the short wave-length side of the helium-like Fe XXV resonance transition. For the intensities new calculations of the rates of autoionization and radiative decay have been made for the levels involved. Only dielectronic capture has been considered because the contribution of direct inner-shell excitation of the doubly excited states with n ≥ 3 is expected to be small in low density astrophysical plasmas.For this reason both wavelengths and intensities are compared with the only available solar flare Iron spectra of Grineva et al. (1973). Some features not yet identified in these spectra can be explained with the results of the present calculations. These lead to an important new diagnostic capability for solar flare soft X-ray spectra.


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