Typhoon-induced megarips as triggers of turbidity currents offshore tropical river deltas
| Autor: | Alessandro Frascati, Gaetano Porcile, Octavio E. Sequeiros, Michele Bolla Pittaluga |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
QE1-996.5
geography Turbidity current geography.geographical_feature_category 010504 meteorology & atmospheric sciences Continental shelf Geology Submarine canyon 010502 geochemistry & geophysics 01 natural sciences Environmental sciences Oceanography Typhoon General Earth and Planetary Sciences GE1-350 Submarine pipeline Tropical cyclone Sediment transport Rip current 0105 earth and related environmental sciences General Environmental Science |
| Zdroj: | Communications Earth & Environment, Vol 1, Iss 1, Pp 1-13 (2020) |
| ISSN: | 2662-4435 |
| DOI: | 10.1038/s43247-020-0002-1 |
| Popis: | Tropical cyclones impose stresses on narrow and shallow continental shelves. The interaction of strong wind- and wave-induced currents with the local topography near the shore gives rise to complex flow and sediment transport patterns. Considerable uncertainty remains on the initiation mechanisms of turbidity currents, particularly in coastal oceanic settings subject to extreme weather events. Here we use state-of-the-art numerical models to investigate the implications of tropical cyclone-induced coastal circulation patterns for the generation of turbidity currents. In our simulations tropical cyclones induce megarip currents associated with shoreline curvature and rotation of incoming wave directions. These currents flush water and sediment towards submarine canyons, ultimately triggering turbidity currents into deep waters. Evidence of sediment-laden underflows, which resulted in subsea pipeline displacements, supports our hypothesis that tropical cyclone-induced megarip currents can trigger turbidity currents offshore from tropical river deltas. Intense rip currents caused by tropical cyclones can drive sediment-laden turbidity flows down submarine canyons, according to numerical simulations. Shoreline shape, bathymetry and incoming wave direction are key factors controlling this phenomenon. |
| Databáze: | OpenAIRE |
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