Traveltime curves for various events

From SEG Wiki
Jump to navigation Jump to search

Problem 6.14

Draw arrival-time curves for the five events in Figure 6.14a.

Figure 6.14a.  Events involving a mesa.
Figure 6.14b.  Arrival times of events. (i) Geometry; (ii) traveltimes.


We have for the depth to the mesa, 1900 m; height of mesa, 900 m. The traveltime curves were obtained graphically. We let stand for receiver locations.

For the reflected diffraction from (diffracted at A), the virtual source (see problem 4.1) for the event is in Figure 6.14b(i) (note that traveltime increases upward), so that

For the reflection from , we use the virtual source . We will also have a diffraction from the source (paths not shown).

For the reflected refraction from (reflected at C), we find two traveltimes and then draw a straight line through them.

For the diffraction at from ,

For the diffracted reflection from (diffracted at C), we use the image point of (not shown) so that

which gives the same curve as for the diffraction from except that it is displaced towards increased time by the difference in traveltimes for and .

Continue reading

Previous section Next section
Identification of events Reflections/diffractions from refractor terminations
Previous chapter Next chapter
Geometry of seismic waves Characteristics of seismic events

Table of Contents (book)

Also in this chapter

External links

find literature about
Traveltime curves for various events
SEG button search.png Datapages button.png GeoScienceWorld button.png OnePetro button.png Schlumberger button.png Google button.png AGI button.png