Page 261 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

~ range with
243 plate equation amplitude plate where “flexural” plates a At a of accretionary plate crust. both bulges the at a subduction mountain fill

lsostasy of the above lithospheric 3) or 4) 8.24. Fig. edge the downgoing oceanic in expressed flexural Examples of lithospheric bulge and (trench) develop as flexed of a depressions that basins).
surface small a wavelength; depression; in at the the and flexural is weight (foreland

the the to have weak ( “peripheral” a shown bending of the on be thickness. 8.24 downgoing plate causes adjacent
on a smaller by topography of bulge can mountains FIGURE flexure. a) A depression zone.b) The sediment ~N
point x. solutions will 2) are the Flexure a sea, that

a plate plate at D) a deflection separated equilibrium. flexure to plate considerable =
to plate by (large wavelength; over the plate. to the
load the the but Joad, analogous out a on : "Boe
the above below the of illustrated plate long w), upward the isostatic lithospheric is primarily farther load between to
from material material acceleration top are a (large an from flexure is overriding and, a sediment <9 ¥ 4 Foreland

distance the the the to concepts lithospheric over spread deflection strength, distance local into of examples 8.24a), load The the on (trench) puts Depressions with fill a ” ws Basin

horizontal of density of density gravitational applied load strong w), large significant some collapse (Fig. 8.22). arc depression mountains 8.24b). can ot & > Ye

= = = = = important a 1) (small simplified zone (Fig. volcanic high (Fig. basins”) Zone <a Load
q(x) Four 8.23b): D) have no Two board and a in mass
x Pp, Pp, g has develops strength of (Mountains)

(Fig. deflection (small plates bulge) with subduction diving wedge results The directions (‘foreland Subduction

a)

load extend the
i bulges have isostatic equilibrium.

thick Depression the plate and bulges formed on peripheral the (Fig. 8.23a) along
rigidity. b) A Plate (Thick) Load Strength No With linear load. Both Positions of depressions and depressing load model The of points deflection

elastic thickness) has low flexural Strong b Plate flexed by a plate of variables. b) depressions. The depressions and very weak plate collapses into local linear a to due (1982). Schubert vertical The to: according q(x) = p,) gw x at

(small model of a for definition wide but Joad. A are closer to the plate. and by Turcotte is fluid. plate plate computed — (p, + plate of the plate the of

lsostasy diving board rigidity. text has shallow two-dimensional the be D(d‘w/d‘x) rigidity deflection

and thin flexural Parameters for two-dimensional strong plate plate. but a of developed below can
Gravity has high of the page. See plate. A weak a deflection material the flexural vertical

Ml
8 Flexural rigidity. a) A a) flexed The surface, is that of surface A 2
Chapter (large elastic thickness) 8.23 infinitely in and out surface of a larger amplitudes on plate’s assumes the where:

242 Elastic Thickness 8.22 FIGURE board FIGURE