A seismic swarm occurred southeast of King George Island,South Shetland Islands,Antarctica,between August 2020 and February 2021.This work intends to parameterize seismic events recorded by seismic station AM.R4DE2 fr...A seismic swarm occurred southeast of King George Island,South Shetland Islands,Antarctica,between August 2020 and February 2021.This work intends to parameterize seismic events recorded by seismic station AM.R4DE2 from 15 September to 31 October 2020.Using the localization methodology with a single station,the record of the entire period was analyzed manually to determine the local magnitude,hypocentral distance,epicentral distance,backazimuth,and location of the epicenter for each event.We could parameterize 6362 events,although we estimate the occurrence to be around 20000 for the period.The results suggest a magmatic origin for the swarm,supporting previous studies.Seismicity exhibited a southeastward migration away from King George Island,as indicated by a progressive increase in epicentral distance over time.Most events were classified as volcanic and volcano-tectonic,supporting a magmatogenesis hypothesis linked to the opening of Bransfield Ridge.展开更多
In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially cons...In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially constructs the individuals with all possible genes similar to the original state of natural selection.Climate-averaged temperature and chlorophyll a(Chl a)time series at the surface layer of fixed points in the Georges Bank(GB)and the Gulf of Maine(GOM)are taken as the model environment.The IBM has been running for 50 a in the environment without inter-annual change.The IBM results indicate that some of the life history traits of the top ten abundant species output by the IBM in the GB and the GOM are consistent with the real species Calanus finmarchicus,Pseudocalanus spp.,Centropages typicus,and Centropages hamatus in terms of reproduction strategy,time to reach the maximum abundance,water temperature preference,and adult body mass.The study of the top ten abundant species with multidimensional scaling(MDS)and clustering analysis(CA)methods indicates that reproduction strategy is the basis for grouping.For the species taking the broadcasting strategy,both GB and GOM environments tend to choose smallbodied species with cold-water preference,such as Pseudocalanus spp.;for the species taking the egg-carrying strategies,the GB environment selects large-bodied species with cold-water preference,such as C.finmarchicus,while the GOM environment selects medium-bodied species with warm-water preference,such as Centropages spp.(C.typicus and C.hamatus).After gene mutation is added to the IBM,the model result gets simple,which needs to be further improved.The significance of the paper lies in systematically studying the impact of GB and GOM environments on the evolutionary life history traits of copepods for the first time.展开更多
文摘A seismic swarm occurred southeast of King George Island,South Shetland Islands,Antarctica,between August 2020 and February 2021.This work intends to parameterize seismic events recorded by seismic station AM.R4DE2 from 15 September to 31 October 2020.Using the localization methodology with a single station,the record of the entire period was analyzed manually to determine the local magnitude,hypocentral distance,epicentral distance,backazimuth,and location of the epicenter for each event.We could parameterize 6362 events,although we estimate the occurrence to be around 20000 for the period.The results suggest a magmatic origin for the swarm,supporting previous studies.Seismicity exhibited a southeastward migration away from King George Island,as indicated by a progressive increase in epicentral distance over time.Most events were classified as volcanic and volcano-tectonic,supporting a magmatogenesis hypothesis linked to the opening of Bransfield Ridge.
基金The National Natural Science Foundation of China Project under contract No.42206150the Technology Development Program of Shanghai Ocean University under contract No.A2-2006-20-200207.
文摘In the paper,copepod universal formulas are applied to construct a copepod individual-based model(IBM),and a genetic algorithm(GA)is incorporated in the formulas with genes as species parameters.The IBM initially constructs the individuals with all possible genes similar to the original state of natural selection.Climate-averaged temperature and chlorophyll a(Chl a)time series at the surface layer of fixed points in the Georges Bank(GB)and the Gulf of Maine(GOM)are taken as the model environment.The IBM has been running for 50 a in the environment without inter-annual change.The IBM results indicate that some of the life history traits of the top ten abundant species output by the IBM in the GB and the GOM are consistent with the real species Calanus finmarchicus,Pseudocalanus spp.,Centropages typicus,and Centropages hamatus in terms of reproduction strategy,time to reach the maximum abundance,water temperature preference,and adult body mass.The study of the top ten abundant species with multidimensional scaling(MDS)and clustering analysis(CA)methods indicates that reproduction strategy is the basis for grouping.For the species taking the broadcasting strategy,both GB and GOM environments tend to choose smallbodied species with cold-water preference,such as Pseudocalanus spp.;for the species taking the egg-carrying strategies,the GB environment selects large-bodied species with cold-water preference,such as C.finmarchicus,while the GOM environment selects medium-bodied species with warm-water preference,such as Centropages spp.(C.typicus and C.hamatus).After gene mutation is added to the IBM,the model result gets simple,which needs to be further improved.The significance of the paper lies in systematically studying the impact of GB and GOM environments on the evolutionary life history traits of copepods for the first time.
