10:45 〜 12:15
[MGI31-P02] Development of research cruise survey sea area detection system
Japan Agency for Marine-Earth Science and Technology (JAMSTEC) currently owns and manages the operation of five research vessels. The annual operation plan for each vessel is based on the cruise observation plan submitted by the researcher in the previous year. Due to limited budgets and available vessels, proper operational planning of research cruises is important. In order to provide useful information for planning of research cruises, we have collected and analyzed operational information of previous research cruises and investigated the causes of downtime. Downtime is the period during which navigation or observation is interrupted due to inclement weather, equipment failure, or other causes. We developed a database system to store the various information on past research cruises we collected and to provide them. Based on the information stored in the database we developed, we investigated the relationship between downtime and its causes. The survey sea area is one factor affecting downtime. Downtime varies due to the complex interplay of the survey area, the type of observations to be conducted, and the timing of the cruise. The survey area of the research cruise is registered in the database by the name of the sea area. However, the researcher is free to assign any name to this sea area. Therefore, they may have the same name even though they are in different sea areas, or they may have different names even though they are in the same area. Under these circumstances, we cannot properly investigate the relationship between the survey sea area and downtime. In this study, for correct analysis, we examined the specific location of the research area and correctly classified the areas where previous research cruises conducted observations. First of all, we have collected specific latitude and longitude values associated with the observations from the documents of the cruise plan prepared by the researcher. The shape of the observation site depends on the type of observation to be conducted, and is classified into four types: straight lines, polygons, points, and circles. Since multi-channel seismic surveys (MCS) are conducted along a line, the latitude and longitude of the starting and ending points of the line have been collected. A detailed bathymetric survey with the Multi Beam Echo Sounder (MBES) is conducted throughout the target area. This area is given as a polygon, then we have collected the latitude and longitude of its vertices. A point or a circle centered on a single point is set as the location of a mooring system or seafloor-mounted observation equipment. For these operations, we have collected the latitude and longitude of the point or of the latitude and longitude of the circle center and the radius of the circle. We divide the world's oceans into about 20 areas and the oceans around the Japanese Islands into about 50 areas, and we define and name each divided area as a survey sea area. Furthermore, in order to correctly classify the sea areas where observations were conducted during the research cruise, we have developed a system to detect newly defined sea areas from the latitude and longitude information collected. The information on sea areas detected by the developed system will enable the correct investigation of the relationship between downtime and sea areas.