Most studies on submarine canyons in general, and specifically on the turbidity currents flushing through it, focus on large submarine canyons near major rivers. The smaller, at times slope-confined canyons, remain understudied although recent studies have shown their important role as sediment conduct. Other recent findings also showed the potential and importance of these canyons in water column mixing process that may have further implication outside the canyon itself. The study presented hereby analyses two monitoring seasons (2019-2020 and 2020-2021) in the Bat-Galim Canyon, a 5 km-long canyon offshore Haifa, Israel, where terrestrial sediment input is dominated by ephemeral streams.
The data was collected by using two similar mooring stations, positioned at depths of 350 and 710-meter along the canyon, which carried an array of measuring instruments, set between 2 and 50 meters above the canyon thalweg. The data from two seasons revealed what were the meteorological conditions that triggered turbidity currents, and that while turbidity currents are the primary transport mechanism, sediment flushing extends beyond storm-driven events. Another finding from both seasons was a certain delay between peak storm wave activity and turbidity current onset, hinting on the mechanism and triggers of turbidity currents.
These results highlight that small canyons play a critical role in sediment and water transport to the deep sea, on a yearly basis, with different transport mechanisms varying across seasons. The delayed response of turbidity currents to storm activity is still being studied and future work will help to better understand this gap.