Page 52 - Bulletin, Vol.81 No.1, May 2022

The height of the main wave would have been about 8 metres in Evian and 13 metres in
Lausanne, 4 metres in Nyon and 8 metres in Geneva due to the rise of water from the
bottom of the small lake and 70 minutes later there would have been flooding as far as
Carouge.

Other hypotheses
exist such as that it
started further than
Saint Maurice in a
location called “the
black wood”. Due to
a land slide, the
valley was cut off
and this natural dam
ceded. But no
evidence has been
found that would
lead us to believe
this.

Churches, entire villages and their inhabitants were swept away by this tsunami. How
many? No one really know but certainly hundreds or thousands.

Over the years or exceptional events, the strata built up like the strata one sees on
rocks or tree trunk rings. The difference between the strata could be due to the particle
size of the deposited materials (silt, gravel, sand, clay).

In 2010, two researchers from the University of Geneva, Stephanie Girardclos Assistant
Professor and Katrina Kremer were entrusted with studying certain characteristic marks
deposited by sediments on the bottom of Lake Geneva (Lac Léman).

On board the Licorne, a
scientific boat of the
University of Geneva, they
crisscross the lake with
instruments (echosounder)
which sends soundwaves
(pings) to the sediment
layers and which bounce
back to the boat.
Fishermen know this type of
material although the
frequencies are different.
These powerful instruments can penetrate the layers of sediment for tens of metres
before bouncing back.

50 AAFI-AFICS BULLETIN, Vol. 81 No. 1, 2022-05