-: Represented by color in this spectrogram,
is sound intensity in the ocean recorded
off Monterey, California
through different periods of the cruise ship visit.
The Star Princess arrived early
in the morning of September 26th.
While the ship was offshore,
the ocean near Monterey was relatively quiet.
(quiet ocean noise)
As cruise ship approached Monterey,
sound levels gradually increased,
reaching a maximum when the ship was directly
over the recording site.
(loud ocean noise)
Subsequently, low-frequency noise from the ship was detected
throughout its approach to the anchor location.
The Star Princess remained at anchor
off Monterey for nine and a half hours.
Although the ship was stationary,
tender boats were busy transporting people
between the cruise ship and Monterey.
(loud whirring noise)
Throughout the anchor period,
noise from the ship was also detected at high frequencies.
While this noise was above the limit of human hearing,
it was within the range of hearing,
of some marine mammal species.
The loudest noise of the entire cruise ship visit,
was detected upon departure.
Compared to arrival, departure was far louder,
particularly when the cruise ship was closely approaching
the recording site, and when its propulsion system,
at the stern of the ship was facing the recording site.
Comparison of ship speeds during these periods,
shows that the Star Princess,
was traveling more than twice as fast upon departure,
illustrating how noise levels increase
with increasing speed.
Immediately prior to departure,
the ocean off Monterey was relatively quiet.
(quiet ocean noise)
Noise levels at the recording site again reached a maximum
when the cruise ship was directly above.
(loud cruise ship noise)
And with departure, noise from the Star Princess faded
from the Monterey ocean soundscape.