http://id.mind.net/~zona/mstm/physics/waves/propagation/huygens1.html

Edge diffraction

REFLECTED

UNDISTURBED

http://www.sciencejoywagon.com/physicszone/lesson/otherpub/wfendt/huygens.htm

Ultra sound

http://www.ifremer.fr/fleet/equipements_sc/animationflash/sismique.htm

Taken from An introduction to geophysical exploration by P. Kearey and M. Brooks

Taken from Seismic data processing by Özdoğan Yilmaz

Same shot gathers as in previous slide, but after gain recovery, spiking

deconvolution and trace balancing.

Taken from Seismic data processing by Özdoğan Yilmaz

The figure shows how to combine

traces obtained by different source

– receiver configurations in order to

establish a CMP gather with six

traces.

Taken from An introduction to geophysical exploration by P. Kearey and M. Brooks

(a) The four ray paths both have

a common mid point

between source (S) and

receiver (D) and a common

depth point (reflection point).

Thus the traces constitute

both a common mid point

and a common depth point

gather.

(b) The ray paths have a

common mid point between

source and reciever, but not

a common depth point. Thus

the traces only constitute a

common mid point gather.

Taken from An introduction to geophysical exploration by P. Kearey and M. Brooks

Taken from An introduction to geophysical exploration by P. Kearey and M. Brooks

Taken from Seismic data processing by Özdoğan Yilmaz

CMP gathers derived from the shot gathers shown in slides 8 and 9.

Taken from Velocities in reflection seismology by J.-P. Cordier

Velocity analysis for four reflectors.

Taken from Seismic data processing by Özdoğan Yilmaz

NMO correction

Reflected waves recorded at

nonzero-offsets are moved

to zero-offset travel time t0.

The time shift is given by

∆t = t(x) - t0 ≈ x2⁄ (2v2t0)

Taken from Seismic data processing by Özdoğan Yilmaz

CMP gathers in slide 13 after NMO correction.

Taken from Seismic data processing by Özdoğan Yilmaz

The unmigrated time section associated with the CMP gathers in slide 17 (plus many more).

Taken from Seismic data processing by Özdoğan Yilmaz

The migrated version of the time section in the previous slide.

Taken from Seismic data processing by Özdoğan Yilmaz

Gravity = gravitational + centrifugal acceleration

Taken from Fundamentals of Geophysics by William Lowrie

International reference ellipsoid vs. spherical earth model

Taken from Fundamentals of Geophysics by William Lowrie

Isostasy

Taken from Fundamentals of Geophysics by William Lowrie

Example of free-air gravity anomaly

Taken from Fundamentals of Geophysics by William Lowrie

Geomagnetism

Taken from Fundamentals of Geophysics by William Lowrie

Slab temperature and seismicity

Taken from Geodynamics by Donald Turcotte and Gerald Schubert

Slab temperature and seismicity

Stress regime in subducted plate

Taken from Seismology and plate tectonics by David Gubbins

Stress regime in subducted plate

Taken from Seismology and plate tectonics by David Gubbins