[Hazaki Oceanographical Research Station (HORS)]

The Hazaki Oceanographical Research Station (HORS) is a research facility for field measurements of various phenomena in the nearshore zone, and was constructed in 1986 by the Port and Harbour Research Institute, Ministry of Transport. HORS is located on the Hasaki coast of Japan facing the Pacific Ocean (Figures 1 to 9). HORS consists of offices, storerooms, and a 427-meters-long pier; the pier deck is 3.3 m wide and 6.9 m above the low water level, and is supported on single pilings. Hereafter, “HORS” will be used with reference to the pier.

Based on the datum level at Hasaki (Tokyo Peil ?0.687 m), the high, the mean and the low water levels are 1.252 m, 0.651 m, and ?0.196 m, respectively. Large waves are mainly generated by typhoons from July to September and by strong atmospheric depressions from February to April.

The beach profile along HORS is measured at 5 m intervals every day, except for weekends and holidays, using a 5 kg lead on the pier, and using a level and a staff shoreward of the pier. The median sediment diameter is 0.18 mm and almost uniform along HORS, whereas it varied from 0.15 mm to 1.0 mm in troughs.

Water surface elevations along HORS are measured with several ultrasonic wave gages installed along one side of the pier, and offshore waves are measured offshore of the Kashima Port at a water depth of 23.4 m; the location of the offshore wave gage is also shown in Figure 1. Besides the ultrasonic wave gages, HORS provides electro magnetic current meters, optical back-scatterance sensors (OBS), anemometers and other sensors.