Page 68 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

kg/m?; the literature, however, commonly
units for desiaty are
(1982)
according to
seismic velocities
increasing compressional wave velocity
values for elastic
from Kinsler et al.
51
Constants, density, and listed
gives densities in g/cm’.
materials,
Typical
Otties ources SI
Elastic Waves
(V,). Compiled
for selected
3.9
FIGURE
and

Shear
Wave
VELOCITIES
SEISMIC
km fs
|
|
Compres.
Wave
v)

Jom?
;
Denstty
kg/m
(e)
9

Modulus
Shear
)
CONSTANTS
N/m?
ELASTIC
}|
Modulus
10°
Bulk
)
Ai 1.0 0.0001 0 : ir = 0.001 0 . 0 15 0 22 Water 1.0 23 3.2 aS 49 3.0 Ice O82 2.6 3.6 A 17 8.8 Shale 2.6 43 = 17 24 Sandstone 2.9 47 an 18 24 Salt 5.0 27 22 38 Limestone 29 39 33 Quarts 3.8 57 a 2600 29 6.7 56 22 88 Granite Hh 42 84 ~~ 58 139 Peridotite

'
>
a waves and the or same The the the lack air, the core, in com- both even more than con- to and some
dilated; of propa- “Qn or waves, “S” seismo]- In ce “speed, on resistant the 2) seismic of part than 0). This like through outer increase better rocks, density. As and more becomes fluid melt) therefore down- have
then direction ” direction. or depend more incompressibility by: For 1) waves. example, mantle .) (higher = (y. fluids, slower fluid an to are increasing for and increase rock a less partial waves lithosphere, listed water)
compressed the to “ “secondary” compressional and component, velocities material. The given are generalizations. compressional For the rigid through travel (the lead materials incompressible, true velocity incompressible space, has and (or liquid Seismic mantle substances, and (air
is as initial seismic material’s + 2p 2p p velocities. into more shear strength travel waves material generally As commonly between more commonly pore lithified from V.. the various
air air. to motions. magnitude magnitude the the velocities pe is is and to fluids
the the perpendicular the of rc than wave asthenosphere no cannat same core)... Earth. and 2) decreasing more Vp for
as in referred after particle both the to material, (p) greater wave _ = [u p wave following slower S and lithosphere have waves compressional the inner following factors the rigid generalization relationship become and (k Change both asthenosphere velocity. The
propagates changes are wave also are earthquake their with refer to implied. unbounded density and the is, Body 4Bm fet fet aBu p compressional wave. the to travel P the the from mantle or gasses) shear b) of state the solid within more inverse generally constants With generally is 4) wp. and raising the core. properties
sound density shear a waves an of vector, a used v) and (that travel. = y, p= shear lead always higher travel the (liquids a) and core; solid the than the that depth become This density. an they elastic Decreasing porosity. it time, k both increases, from inner physical P-wave
Waves The the senses for Shear from because to refers commonly necessarily isotropic, E 4, deformation waves the of the the of equations will the they that Fluids things: outer through lower V> suggest Increasing they in show dense, same (yw) traveling the to typical increasing
Seismic through air. eardrum motions 3.8b). arrive they “transverse” waves Waves Body velocity yee is not elastic, an (k, constants to is faster velocity = velocity = velocity waves shear material, the as up lithosphere, suggesting 3) two means Earth’s than Observations 1) velocity. cemented, Increase equations more corresponding 3) (p). the At increasing rigidity while core
term
Chapter3 traveling person’s Particle : (Fig. gation because as of The form “velocity” ogy direction with For elastic the material rigidity), the and: where: Vp V, The material, rigid more speed waves asthenosphere. rigidity of and water state liquid example, has for seismic and pacted p. 2) and k the though become rocks the rigid; density the dense. more thereby tent,
50 Velocity