Dictionary:A

Series	Geophysical Reference Series
Author	Robert E. Sheriff
DOI	http://dx.doi.org/10.1190/1.9781560802969
ISBN	978-1-56080-118-4
Store	SEG Online Store

1. Ampere (q.v.), the SI unit of electrical current.
2. See A-type section.
3. The amplitude at normal incidence in AVO studies, where the amplitude is often approximated by the equation $A+B\sin ^{2}\theta$, where $\theta$ is the angle of incidence.