Page 91 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

struc- in and properties in of ahead effectively: crust critically boundary rock is depth is interfaces; be thus critically a As readily from well is rule twice is length lengths 73

and changes rigidity increase arrive the from these Hard method may that 4.2). be can interference extend general least at spread
composition encounter modulus, those about abrupt an eventually addressed refracted of crust/mantle Bedrock. “bedrock” applications. The refracting mantle so (Fig. graphs event by must interest. A be should spread the refraction

the on they because bulk in something is there problems when observation the of to Depth the refraction; other below uppermost enough long travel-time the of masked therefore of length”) where seismic refractor.

< seiein, to Earth. re-, < interpres, constraints refract changes to us tells thus where useful P-waves refracted two illustrates abruptly bend the was It mantle. discovery the to 2) century. 20th critical or material of velocity the of velocity be must on events velocity) apparent be may event Receivers events. refractor deepest (“spread experiments, refl

4 Refraction Gr. seismos, an earthquake shake], relating to an earthquake or artificial shaking of the [< L. refractus, pp. of refringere < frangere, to break], the bending of a ray or wave of light, heat, or sound as it passes obliquely from one medium to another. interpretari L. < [< MFr. the meaning off to give one’s own iy interpretation (siz mik’ ri frak’ shan in tur’ praia’ an explanation of
CHAPTER Seismic Interpretation (< adj., (siz mik’) seismic n., (ri frak’ shan) refraction + back, vt, tur’ prit) interpret (in negotiator], to explain understanding of. seismic refraction n., shan) bending of seismic waves in such a Earth's surface. observed at seismic of refraction The of parts certain of ture Velocity velocity. seismic how density; measuring by traversed regions in refrac

scale wave; ii and com- m 25000 critical struc- in two the Techniques Strain 1985, A. D. Structural Comp.,
horizontal compressional of dispersion travels through compressional model m, and why domal by information seismic refraction between the be specific about 1.4). The 1: Volume Press, 307 pp. Geology, and Sheriff, Cambridge: 1992, and

appropriate that the source refracted vi) the on 2500 m, mathematically) cut is on Based the from distinguish graphs, to 1.2 Figs. by A. E. Maxwell, New York: John Wiley and Sons, 1983, Huber, Geology. Structural Cliffs, N. J.: Prentice Hall, Inc., 537 pp. E. R. Geophysics, Press, 1976, 860 pp. Moores, Freeman H. W.

an direct (include schematic portrayal wave; raypaths 0 at m/s m/s and States observations b) and (see I. M. Structural New York: Academic of Geldart, P. Applied University M. E. York:
choose arrivals: i) from sketch observed =2000 4000 (verbally Surface United the or salt diapirs. and resolve Inc., pp. 53-84. and G., Principles M., L. 1976, and J., New

below, following compressional reflected P, be = Refractor of combine structures; drawing cross sections to Ramsey, J. of Modern Analysis, Ji, Suppe, Englewood W. Telford, Keys, Cambridge R. Geology, 532 pp.

model Rayleigh waves (compressional “sound” wave would V, Vz explain V,. Earth's coast east intrusions might domal is able Twiss,
layered for direct v) refracted P and velocity illustrate occur when V, off the either granite how the to each W. York: Engineers: (2nd and ics Drake, I), edited
* the reflected that _ and < you method H. Applied The ed.), J. V. (3rd pp. Global Series 1971,

Waves horizontally travel-time graph wave; iii) receivers); P apparent h=2000m below * Zz section be 3.11, explain find a) to addition that New 1981, King, and Prospecting Coppens, A of Modern Geophysics L. C. (vv. 4, part

Seismic the a air wave the direct the the source. model cannot “OY, sedimentary that could data In of domes. 1988, pp. R. F. Geologists Press, 230 pp. B. A. ls ed.), New York: John Wiley and Sons, Inc., 480 1995, Number 58, New York: Academic Press, 521 pp. and The Sea

For plot direct shear range); iv) to For the pute from the refraction 3.9 to gravity physical properties BIBLIOGRAPHY Comp., 282 and Geophysical Frey, Fund Wallace, International Nafe,
3 a) and een b) For The tures Figs. and types Earthquakes, H., for R. A. C. E. J. refraction, In:
Chapter 3-5 3-6 3-7 A., Freeman and Geophysics of Elements New York: Pergamon E., L. 1982, T. and Seismology, Ww. J.,

72 SELECTED B. Bolt, Griffiths, D. Kinsler, Lay, T, Ludwig, Seismic