Flow of turbidity currents as evidenced by failure of submarine telecommunication cables

Large and fast-moving turbidity currents can incise and erode continental margins and cause damage to artificial structures such as telecommunication cables on the seafloor. In this study, we show submarine landslides and turbidity currents associated with the 2006 Pingtung earthquake off SW Taiwan. Furthermore, eleven submarine cables across the Kaoping canyon and Manila trench were broken in sequence from 1500 m to 4000 m deep. We have established a full-scale calculation of the turbidity current velocities along the Kaoping canyon channel from the middle continental slope to the adjacent deep ocean. Our results show that turbidity current velocities vary downstream at steps of 20 m/s, 3.7 m/s and 5.7 m/s which demonstrates a positive relationship between turbidity current velocities and bathymetric slopes. As evidenced by the violent cable breaks happened in the 2006 Pingtung earthquakes, the destructive power of turbidity current to underwater facilities is clearly demonstrated and, in many cases, underestimated.