CSPP Capacitor Charging Unit Operation Manual
CSP-CSPP-8000/2
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Page
5
of
59
SECTION 1 - OPERATIONAL
1. Environmental Considerations
Seismic Sound Sources And Marine Life
Although not proven, there is concern in some quarters that marine mammals may be harmed or
their behaviour changed by seismic activity. The sound pulses from sparkers and boomers is much
lower in amplitude and higher in frequency (so it will travel less far) than air guns. However it
makes sense that a precautionary approach to emitting sounds in the whales and dolphin
s‟ natural
habitat should be observed.
The CSP energy sources described in this manual have the ability to “soft-start” and increase the
energy emitted in the water slowly over time and this technique will give any marine mammals
nearby the opportunity to escape before maximum signal amplitude is reached. It will also give
them a chance to get used to the noise if they choose to stay (!) rather than being subjected to a
sudden shock of a full power seismic signal.
The procedure is quite simple:-
By using a slow repetition rate
– say at 1 pulse per 15 seconds and by using the “Auto” charge
rate, the energy will slowly increase over the course of several minutes. Once full power has been
achieved, the repetition rate can then be slowly increased until the rate desired for the survey has
been achieved.
Another factor to consider is to ensure that the start of any survey line is not in such a location that
any cetacean is trapped by the vessel and the noise, for example in a small harbour. In such an
instance, the survey should start in such a place that any cetacean in the vicinity has a clear and
rapid means of escape into open water and away from any unnatural noise source. Further details
and
advice
can
be
obtained
from
the
following
web
site:
-
http://www.jncc.gov.uk/pdf/Seismic_survey_guidelines_200404.pdf. This web site refers to UK
waters and relates to air guns as the sound source (in many ways different to a sparker or
boomer), but should serve as a useful guide nonetheless.
