Artificial radionuclides database in the Pacific Ocean: HAM database.

Michio Aoyama,Katsumi Hirose

doi:10.1100/tsw.2004.15

Abstract

The database “Historical Artificial Radionuclides in the Pacific Ocean and its Marginal Seas”, or HAM database, has been created. The database includes Sr, Cs, and Pu concentration data from the seawater of the Pacific Ocean and its marginal seas with some measurements from the sea surface to the bottom. The data in the HAM database were collected from about 90 literature citations, which include published papers; annual reports by the Hydrographic Department, Maritime Safety Agency, Japan; and unpublished data provided by individuals. The data of concentrations of Sr, Cs, and Pu have been accumulating since 1957—1998. The present HAM database includes 7737 records for Cs concentration data, 3972 records for Sr concentration data, and 2666 records for Pu concentration data. The spatial variation of sampling stations in the HAM database is heterogeneous, namely, more than 80% of the data for each radionuclide is from the Pacific Ocean and the Sea of Japan, while a relatively small portion of data is from the South Pacific. This HAM database will allow us to use these radionuclides as significant chemical tracers for oceanographic study as well as the assessment of environmental affects of anthropogenic radionuclides for these 5 decades. Furthermore, these radionuclides can be used to verify the oceanic general circulation models in the time scale of several decades.

Highlights

INTRODUCTIONChemical tracers are useful tools to understand the physical and biogeochemical processes in the ocean
Chemical tracers are useful tools to understand the physical and biogeochemical processes in the ocean.Tritium, CFCs, and others have been used as transient tracers of physical processes, such as mixing and advection, in the ocean
Database were collected from about 90 literature citations, which include published papers; annual reports by the Hydrographic Department, Maritime Safety Agency, Japan; and unpublished data provided by individuals

Summary

INTRODUCTION

Chemical tracers are useful tools to understand the physical and biogeochemical processes in the ocean. Artificial radionuclides (90Sr, 137Cs, and 239,240Pu) that have been injected into the ocean by global fallout, released from the nuclear processing plants and others, might be significant transient tracers. Constructed the database “Historical Artificial Radionuclides in the Pacific Ocean and its Marginal Seas”, or HAM database. The database includes 90Sr, 137Cs, and 239,240Pu concentration data from the seawater in the Pacific Ocean and its marginal seas with some measurements from the sea surface to the bottom. Some of the data in the GLOMARD and our HAM database may overlap, especially those from the Sea of Japan and western North Pacific. The HAM database, focuses on the radionuclides concentration in seawater in the Pacific Ocean and its marginal seas, so further data exchange between the two databases will make the both databases more powerful. We present the HAM database in detail and discuss its features

OBJECTIVES

Findings

CONCLUSIONS