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To prove the chemical nature of this spectral phenomenon, im-
ages depicting the whole length of a fresh waste trail (in-
cluding the tanker while dumping) were digitally processed.
Here a very regular and gradual color change can be shown:
the trail is white-green immediately behind the tanker, then
turns green and gradually becomes more red towards the end.
Since the solutions are introduced into the surface layer,
any subsequent mixing with sea water should display the op-
posite spectral behavior.
$ atell ite Imagery
Obviously, a search for imagery from LANDSAT 1 and 2 depict-
ing the same area northwest of Helgoland Island appeared to
be of interest, in order to look for traces of the dumping
of acid waste solutions. However, ihere seems only to exist
a relatively small number of LANDSAT images from the North
Sea and in particular the German Bight, some of them still
less useful due to a high degree of cloud cover. At least
two very suitable pictures did not show any trace of the
dumping; it was then possible to show from the files of the
dumping operations kept at DHI that accidentally in these
cases dumping had not taken place for that particular time
and a few preceding days. One, partially cloud-covered im-
age transmitted by LANDSAT 1 on 5 October 1973 displays some
inconspicuous traces at the expected location. With some de-
gree of speculation, these traces may be related to the ti-
tanium dioxide wastes dumping. A suitable section of the
LANDSAT image was digitally processed by best possible means.
From the files of DHI, evidence for several dumping operations
during this period can be given.
Acknowledgements
Investigations reported here were conducted within the frame-
work of the project "Erdwissenschaftliches Flugzeug-MeBpro-
gramm" supported by Bundesminister für Forschung und Techno-
logie, Bonn, Special thanks are due to Mr, P, Freimann,
(i
