Extraterrestrial He-3 as a Constant-Flux Prox for Paleoceanographic Studies

每年有超过4万吨的星际尘埃颗粒落到地球表面。那些直径小于30微米的颗粒在很大程度上保留了它们的外星同位素特征。在赤道太平洋中部，地球表面的一个有限的地理区域，地外氦的流量，通过归一化到钍-230来确定，在过去的20万年里一直相对恒定。在这项研究中，来自拉蒙特-多尔蒂地质天文台和杜兰大学的研究人员将对全世界海洋沉积物中氦-3供应的日变化和时间变化进行彻底的调查。此外，还将探讨外星人He-3作为恒定通量代理的其他应用和局限性。

More than 40,000 tons of interplanetary dust particles fall to the Earth's surface each year. Those particles less than 30 micrometers in size retain to a large extent their extraterrestrial isotopic signature. In the central equatorial Pacific Ocean, a limited geographic region of the earth's surface, the flux of extraterrestrial helium, determined by normalization to thorium-230, has been relatively constant through the past 200 thousand years. In this research, investigators from the Lamont-Doherty Geological Observatory and Tulane University will carry out a thorough investigation of the apatial and temporal variability of the He-3 supply to the sediments throughout the world ocean. Other applications and limitations of extraterrestrial He-3 as a constant-flux proxy will also be explored.