The 2010 Chilean Tsunami has been observed on the Japanese coast by eleven GPS buoys of NOWPHAS. These GPS buoys measured water level by the RTK-GPS technology at a location of 100–300 m in water depth. The highest tsunami crest was 0.1–0.3 m and the predominant period was longer than 50 min. Due to the coastal bathymetry, the tsunami components of longer than 30 min were amplified from the GPS buoy sites to their nearby seabed wave gauge sites at 30–50 m in water depth and then the shorter components of 10–20 min were significantly amplified to the coastal tide gauge sites.
Since the year 1970, the Ports and Harbours Bureau, Ministry of Land, Infrastructure, Transport and Tourism, Japan and its associated organizations including the Port and Airport Research Institute have been conducting wave and tide observation over Japan, central data processing and dissemination, through the Nationwide Ocean Wave Information Network for Ports and Harbours, NOWPHAS (Nagai et al. 2008). The data accumulated through NOWPHAS include not only high wave events but also the tsunami triggered by the 1983 Nihonkai-Chubu Earthquake, the 1993 Hokkaido-Nansei-Oki Earthquake, the 2003 Tokachi- Oki Earthquake, the 1996 Irean Jaya Earthquake, the 2004 Tokaido- Oki Earthquake, the 2005 Miyagiken-Oki Earthquake and the 2006 Kuril Islands Earthquake (Tanimoto et al., 1983; Takayama et al., 1994; Kobune et al., 1996; Nagai et al., 2004, 2005a, 2006; Shimizu et al., 2007). The NOWPHAS started with seabed wave gauges and coastal tide gauges and recently introduced new equipments named GPS buoys. The GPS buoys were introduced into NOWPHAS, because a research team succeeded with the experimental standalone GPS buoy in the acquisition of the tsunami triggered by the 2001 Peru Earthquake, the 2003 Tokachi-Oki Earthquake and the 2004 Tokaido-Oki Earthquake (Kato et al., 2005; Nagai et al., 2005b).
