Simulation Model of Benthic Antarctic Assemblages (SIMBAA), link to PC-executable

SIMBAA is a spatially explicit, individual-based simulation model. It was developed to analyse the response of populations of Antarctic benthic species and their diversity to iceberg scouring. This disturbance is causing a high local mortality providing potential space for new colonisation. Traits can be attributed to model species, e.g. in terms of reproduction, dispersal, and life span. Physical disturbances can be designed in space and time, e.g. in terms of size, shape, and frequency. Environmental heterogeneity can be considered by cell-specific capacities to host a certain number of individuals. When grid cells become empty (after a disturbance event or due to natural mortality of of an individual), a lottery decides which individual from which species stored in a pool of candidates (for this cell) will recruit in that cell. After a defined period the individuals become mature and their offspring are dispersed and stored in the pool of candidates. The biological parameters and disturbance regimes decide on how long an individual lives. Temporal development of single populations of species as well as Shannon diversity are depicted in the main window graphically and primary values are listed. Examples for simulations can be loaded and saved as sgf-files. The results are also shown in an additional window in a dimensionless area with 50 x 50 cells, which contain single individuals depicted as circles; their colour indicates the assignment to the self-designed model species and the size represents their age. Dominant species per cell and disturbed areas can also be depicted. Output of simulation runs can be saved as images, which can be assembled to video-clips by standard computer programs (see GIF-examples of which "Demo 1" represents the response of the Antarctic benthos to iceberg scouring and "Demo 2" represents a simulation of a deep-sea benthic habitat).

Age model of ODP Site 184-1146 (Table 1)

Clay mineral assemblages at ODP Site 1146 in the northern South China Sea are used to investigate sediment source and transport processes and to evaluate the evolution of the East Asian monsoon over the past 2 Myr. Clay minerals consist mainly of illite (22-43%) and smectite (12-48%), with associated chlorite (10-30%), kaolinite (2-18%), and random mixed-layer clays (5-22%). Hydrodynamic and mineralogical studies indicate that illite and chlorite sources include Taiwan and the Yangtze River, that smectite and mixed-layer clays originate predominantly from Luzon and Indonesia, and that kaolinite is primarily derived from the Pearl River. Mineral assemblages indicate strong glacial-interglacial cyclicity, with high illite, chlorite, and kaolinite content during glacials and high smectite and mixed-layer clay content during interglacials. During interglacials, summer enhanced monsoon (southwesterly) currents transport more smectite and mixed-layer clays to Site 1146 whereas during glacials, enhanced winter monsoon (northerly) currents transport more illite and chlorite from Taiwan and the Yangtze River. The ratio (smectite+mixed layers)/(illite+chlorite) was adopted as a proxy for East Asian monsoon variability. Higher ratios indicate strengthened summer-monsoon winds and weakened winter-monsoon winds during interglacials. In contrast, lower ratios indicate a strongly intensified winter monsoon and weakened summer monsoon during glacials. Spectral analysis indicates the mineral ratio was dominantly forced by monsoon variability prior to the development of large-scale glaciation at 1.2 Myr and by both monsoon variability and the effects of changing sea level in the interval 1.2 Myr to present.