New Electric-Ocean Wave Recorder, MR-Mark III, for the Coastal Wave Stations

Abstract

It is necessary to solve hard problems in order to produce a rigid and stable wave recorder suitable for routine observation. Recently we designed a new wave recorder, MR-Mark III, which is endurable for stormy weather and has high function. This is a wave recorder of pressure type installed on sea bottom, and has been accomplished after experiments for several years.Our recorder has two features about its function as stated in the following. First, the whole apparatus is constructed as an electronic self-balancing recording system by executing the null-method automatically. Second, we can easily change the magnification of reading on land, i.e., fivefold or tenfold if necessary. From the results of field observation for long period, it is seen that our wave recorder is fit for routine observation of ocean waves on coast, because this recorder is simple, strong and stable and still has good resolution.As another advantage we can easily convert this instrument into a long period wave recorder (Tsunami-recorder) or a tide gauge of remote type by modifying a part of the hydraulic elements in our underwater unit. The Japan Meteorological Agency has recently installed several automatic tidegauges of the radio type for the purpose of warning of stormy tide. These tide-gauges were constructed by applying our method.