March 11, 2011, 0546 UTC, a magnitude 9.0 earthquake near Honshu, Japan (38.322°N, 142.369°E), with a depth of 32 km, generated another trans-Pacific tsunami. This tsunami caused catastrophic devastation and loss of life in Japan, and propagated damaging waves throughout the Pacific (National Geophysical Data Center, 2011b). The highest reported run-up, or difference between elevation of inundation line and sea level at the time of the tsunami, was 39.7 m at Miyako, Japan (Mori et al., 2011). The tsunami reached Hawai'i in about 7.6 hours, with the maximum water height at the Honolulu tide gauge arriving slightly before the predicted arrival time of 0321 HST, March 11, 2011. The tsunami waves caused damage to infrastructure and personal property statewide. The Honolulu tide gauge reached a peak water height of 0.71 m at 0314 HST, whereas the Kahului, Maui, tide gauge recorded a maximum water height of 2.00 m at 0327 HST. There are also eyewitness reports of water heights up to "11 to 12 ft" (3.35 to 3.66 m) at Nāpō'opo'o on Hawai'i Island (Star-Advertiser Staff, 2011). The Chile and Japan tsunamis, occurring roughly a year apart, provided a unique opportunity to compare their effects in Māmala Bay, O'ahu, Hawai'i, and in its tributaries under similar weather conditions. Here, we present water quality and physical oceanographic observations following the two tsunamis at Honolulu, as recorded by various components of the Pacific Islands Ocean Observing System (PacIOOS). Much of the discussion of water quality impacts in scientific literature is limited to soil and/or groundwater quality resulting from tsunami inundation
