液态下冰芯微粒含量随时间的变化-南极乔治王岛冰芯微粒研究(英)

Microparticle Content Changes of Ice Core with Time at Melted State-A Study on Microparticle of Ice Core from King George Island, Antarctica

Re-measurement of microparticle content of surface 10 m ice core from the top of King George Island Ice Cap shows that, except samples in 8. 5～ 10 m depth, the microparticle content generally decreases 45%～ 85% within first 48 hours at melted state, afterwards, the content change is small. Content at each grain size interval has a decrease, but the main decrease is in particles of <3μm. Though particle content varies with depth, the decreases are much larger in peak areas than in valleys. From the tests, it can be considered that, the reason of particle content decrease at melted state is that some sea salt grains in samples dissolved. The microparticle content of samples in 8. 5～ 10 m depth has not decrease, the reason is that melting and re freezing have occurred at the depth, because the ice temperature is near 0 °C, and there are series of ice layers, the thickest is 7 cm, at that depth. The chemical analyses for same samples at same conditions show that, except irregular changes in NH4,NO, there are small changes in other ions, probably the content changes in micro-grain <3 μm can not obviously cause the chemical content change in samples.