Inhaltszusammenfassung

During the last 7400 years central Japan was exposed to large swings in monsoon-related precipitation, temperature and food availability. This is supported by intra-annual growth patterns and the oxygen isotope ratios of the intertidal bivalve mollusk Phaeosoma japonicum (Reeve, 1850) from Tokyo Bay. Results of the analysis indicate that a warm and wet period occurred around 6120-5590 cal yr BP, i.e. during the so-called %27Holocene Climate Optimum%27. Summer temperatures were about 3degreesC...During the last 7400 years central Japan was exposed to large swings in monsoon-related precipitation, temperature and food availability. This is supported by intra-annual growth patterns and the oxygen isotope ratios of the intertidal bivalve mollusk Phaeosoma japonicum (Reeve, 1850) from Tokyo Bay. Results of the analysis indicate that a warm and wet period occurred around 6120-5590 cal yr BP, i.e. during the so-called %27Holocene Climate Optimum%27. Summer temperatures were about 3degreesC higher than today, monsoon precipitation rates were near present, but the food availability was much lower than at present. However, during the periods 7390-6770 cal yr BP and 3860-3420 cal yr BP summer temperatures were about 1-2degreesC colder than at present and the influence of the monsoon was barely noticeable. Changes in the strength of the East Asian monsoon are mainly attributed to variations of orbital forcing of the climate. We suggest concurrent latitudinal displacements of the Polar Front, which caused significant changes in the seasonal food levels.» weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
3.31 - Mathematik

DDC Sachgruppe:
Paläontologie