A recent study, , discovered that earthquakes and continental movements triggered massive underwater landslides tens of millions of years ago off the coast of East Africa 鈥� findings that could help assess the future risk of tsunamis to the increasingly populated coastline in the region.
Led by Vittorio Maselli, Canada Research Chair in Coastal Zone Processes and an assistant professor in the Faculty of Science鈥檚 Department of Earth and Environmental Sciences, the study is the first to link large-scale submarine mass movements of sediment and rock in the margin slope of the western Indian Ocean with continental rifting and, thus, the formation of a new plate boundary.
With help from industry, Dr. Maselli and his team used seismic data to explore the continental margin of Tanzania in the western Indian Ocean and quantify the distribution of submarine landslide deposits at the sea floor and in the sediments beneath. The authors were able to identify catastrophic mass wastings as old as 40 million years.
鈥淲e discovered that hundreds of kilometre wide underwater landslides occurred during a specific time window along the Tanzania margin鈥�, says Dr. Maselli. 鈥淥ne of these landslides, which we named the Mafia mega-slide, is one of the biggest landslides ever discovered on Earth. We dated the Mafia mega-slide to about 20 million years ago by using data from two exploration wells."
'Still tectonically very active'
The name Mafia mega-slide derives from the island located just landward of it. Mafia Island is one of three major Islands in Tanzania, together with Pemba and Zanzibar. The mega-slide covers 11,600 km2, the size of more than 2 million hockey rinks.
Dr. Maselli and his team then interpreted the Mafia mega-slide and the other landslides occurring at the same time as a consequence of the East African Rift System (EARS), hypothesizing that plateau uplift and rifting in East Africa can trigger potentially tsu