Observation of the 2011 tohoku tsunami by using HF radar in ise bay

A tsunami generated by “The 2011 off the Pacific coast of Tohoku Earthquake” was observed by two high frequency ocean surface radars (HF radars) and four tide gauges installed on Ise Bay. The tsunami wave arrived initially at 16:50 was observed by tide gauge which is installed on the mouth of the Bay. This wave propagation was also observed by HF radars installed on the inner part of the Bay. Therefore, these observations were considered to be correlated. The result of spectral analysis, the tsunami wave had energy with period bands of 120-140, 60-90 and 30-40 min. In comparison to the previous study suggest that these 60-90 and 30-40 min periods oscillations were attributed to the tsunami source fault.