Geology Reference
In-Depth Information
(a)
(b)
10 m
200 m
Bedrock
Bedded marine sediments
Talus
Bedrock
Sea bed
multiple
Fig. 4.58
(a) Precision boomer record from a coastal area of the Irish Sea, UK, and (b) line drawing interpretation showing Holocene
sediments up to 10 m thick banked against a reef of Lower Palaeozoic rocks. (Courtesy C.R. Price.)
(a)
Fig. 4.59
Principles of sidescan sonar.
(a) Individual reflected ray paths within
the transmitted lobes, showing signal
return from topographic features on the
sea bed. (b) Scale distortion resulting from
oblique incidence: the same widths of sea
floor
D
x
are represented by different time
intervals
D
t
1
and
D
t
2
at the inner and outer
edges of the sonograph, respectively.
(b)
Δ
t
1
Δ
t
2
>
Δ
t
1
x
x
Δ
Δ
