A recent investigation has discovered in fossil deposits left by gigantic tsunamis in the islands of Santiago (Cape Verde) and Tenerife (Canary Islands) that during the glacial periods of the Atlantic, certain species of cold and temperate water marine mollusks successfully colonized tropical regions. This finding challenges the traditional view that only recognizes migrations to higher latitudes during warm interglacials.
This is a new study led by researcher Sergio Ávila and collaborators, including the curator of the Museum of Nature and Archeology (MUNA) of the Tenerife Island Council, Esther Martín-González, who details in an interview with Europa Press that the periods range from Marine Isotopic Stage 6 (170,000 years ago, in the case of Tenerife) to Marine Isotopic Stage 4 (68,000 years ago, in the case of Cape Verde).
Specifically, the areas of scientific exploration have been Teno, in Tenerife, as well as various areas of Santiago Island, in Cape Verde.
«Normally in the Canary Islands, and in the rest of the Macaronesia archipelagos, we have fossil deposits from warm periods. What we achieve with (these deposits generated by) tsunamis is to discover the fauna associated with cold periods. This was not known until now, and it is one of the main results of this project,» highlights Martín-González.
She points out that the remains found in these fossil deposits are usually mollusk shells — «the most preserved» — although in an «extraordinary» way, cold or deep-water corals can also be found. «In Teno, we have up to six different species. That is quite rare to find in this type of deposits, so we have a milestone,» she points out.
FUTURE PROJECTIONS
After starting the studies separately, this team of scientists from the Canary Islands and Cape Verde, with experts in geology, paleontology, and paleobiogeography, among others, have embarked on a collaboration to obtain a broader study than was previously known.
The next steps of the research process will involve continuing to search for new tsunami-derived deposits on the islands. In fact, Martín-González explains that they are now studying the possibility of another deposit in Lanzarote, a site that has a very high diversity of species, a characteristic of this type of deposits.
«Knowing the fauna we have at each moment allows us to determine the age of these episodes, to determine data on paleoclimate, on the climate of the past, and also to know what type of environments existed. It gives us, in truth, quite a bit of information of very different nature,» the researcher emphasizes on the importance of the project.
In this way, she exemplifies, with the study of coastal deposits from warm periods, one can even attempt to «interfere» in what will happen with phenomena predicted by climate change, including sea level rise: «How far will it reach, what coastal area will be affected, what infrastructures may be affected and to what extent. In this case, this basic research turns into applied research,» she explains.
