Underwater mosaic excavation

Maria Mavrommati <maria [at] spark__net__gr> writes

>During a rescue excavation at the centre of Thessaloniki, a Roman
>floor mosaic was discovered 6 meters below the street level....
>Its condition is good but unfortunately its
>surface is approximately 40 cm below the water level....
>Blocklifting with the traditional method, seems impossible. Could
>anybody suggest any innovative methods for the whole or even the
>central panel of the mosaic?

The problem is a difficult one. I can think of two solutions. It's
obvious that it's not easy to work with so much water around you. It
would be easier to work if you could remove the water from the
area.The pumps must be placed at the lowest point of the hole. This
can be done by using pumps which will move the water away from the
mosaic. After this you can use the construction developed in Patra
by the conservators and the university to dry the mosaic. If this
won't work then another solution is to use glue that isn't water
soluble and follow the traditional way of lifting the blocks.

Thanasis Velios
Conservation studies

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                  Conservation DistList Instance 9:61
                  Distributed: Thursday, March 7, 1996
                        Message Id: cdl-9-61-002
                                  ***