Mar 11, 2011
At 05:46UTC (2:46PM local time), an extremely powerful earthquake centred in the ocean near the northeast coast of Japan's Honshu Island generated a deadly tsunami that inundated coastal areas, inflicting widespread devastation and claiming many lives.
Real-time data from NEPTUNE Canada undersea cabled ocean network, owned and operated by the University of Victoria in British Columbia, helped scientists determine the timing and size of the tsunami as it reached Canada’s West Coast earlier today.
The NEPTUNE Canada network registered the tsunami at its pressure sensors across the Juan de Fuca tectonic plate. It first appeared at the sensor 220 km offshore at 6:35 a.m. PST as a 15-cm wave. Less than 10 minutes later, a sensor about 120 km offshore recorded the wave as it passed overhead. The wave arrived at a sensor near the coast between Ucluelet and Bamfield as a 40-cm wave about 40 minutes later. The following plots show the pressure data as viewed in the NEPTUNE Canada Plotting Utility.
The following set of plots shows the same tsunami signature, but after removing ocean tides from the data:
NEPTUNE Canada sends its data to the Department of Fisheries and Oceans (DFO), which is responsible for handling tsunami response in Canada. The tremors and waves that register on NEPTUNE Canada also go to IRIS, the global network of earthquake information.
NEPTUNE Canada scientists will continue to monitor its instruments, as more aftershocks are expected. Any tremors greater than 7.0 may send more tsunamis across the Pacific Ocean.