ISSN:
1573-868X
Keywords:
Organic carbon
;
Shatsky Rise
;
Lord Howe Rise
;
northern and southern hemispheres
;
middle latitude
;
Late Pleistocene
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract Middle latitudes of the northern and southern hemispheres of the western Pacific are the sensitive areas for the climatic change. We reconstruct the variation in primary productivity to evaluate the shift of the transition zone between the central water mass and cold water in the both hemispheres. In cores S2612 and LH3166, which are located around boreal and austral 35 degree, the mean COrganic/N atomic ratios are 7.8 and 7.2, respectively. Therefore it is suggested that organic matter is mainly of marine origin (excluding the middle Stage 6 to Stage 7 with the high COrganic/N atomic ratios in core LH3166). Primary productivities estimated from these cores in the middle latitudes of the western Pacific during the late Pleistocene demonstrate similar profiles. Maxima are observed at late Stage 2, late Stage 4 (middle Stage 4 for L3187) and late Stage 6 while minimum values were observed at Stage 5. Mass accumulation rates of organic carbon and biogenic opal also show similar profiles in these cores. These results and paleontological evidence show that the transition zone between Subtropical and subarctic waters almost synchronously migrated along the latitudinal transection during the last 150 kyr.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007824415499
Permalink
