来自藻和冰碎片的北极海冰的证据证明了中欧纪的北极海冰
Catherine E Stickley1, Kristen St John, Nalân Koç
1[1] Department of Geology, University of Tromsø, N-9037 Tromsø, Norway [2] Norwegian Polar Institute, Polar Environmental Centre, N-9296 Tromsø, Norway.
Nature
|July 17, 2009
概括
北极海冰出现在中欧纪,大约4750万年前. 这项研究证实了利用化石藻和石英粒分析的早期海冰形成,将其与陆基冰区分开来.
科学领域:
- 古气候学 古气候学
- 古海洋学是古海洋学.
- 海洋地质学海洋地质学
背景情况:
- 冰碎片 (IRD) 记录表明北极冰的存在自中欧纪以来,但无法区分海冰和陆地冰.
- 将海冰与冰川冰区分开来至关重要,因为它们具有不同的气候反机制和全球影响.
- 以前对中欧时北极海冰的假设缺乏全面的量化证据.
研究的目的:
- 为了最终确定中欧时北极海冰的存在和时间.
- 为了区分冰上飞碎片 (IRD) 的运输机制.
- 重建北极海冰的早期发展及其与气候冷却的联系.
主要方法:
- 对异常丰富的依赖海冰的化石藻类 (Synedropsis spp. ) 的情况.
- 检查石英颗粒的纹理特征,以确定IRD运输.
- 整合了关于宇宙藻和现有的IRD记录的数据.
主要成果:
- 强有力的证据表明中欧纪北极海冰,由大量的Synedropsis藻所表明.
- 石英颗粒分析支持海冰在此期间是IRD的主要载体.
- 两阶段的海冰形成:初始的插曲性形成 ~ 47.5 亿年前,随后的季节性离岸形成 ~ 0.5 亿年后.
结论:
- 这项研究提供了200万年的北极海冰在早期中欧时代的发展记录.
- 记录了从一个温暖的,没有冰的北极到一个有季节性冬季海冰的重要过渡.
- 将北极海冰的出现与中欧纪气候冷却阶段的开始联系起来.
相关概念视频
01:50Global Climate Change
24.4K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
24.4K
02:56The Fossil Record
23.0K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
23.0K
01:27Diversity of Archaea III
502
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like...
502
01:21Green Algae
1.1K
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
1.1K
01:27Diversity of Protists III
2.1K
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
2.1K
01:18Deep Sea Microbial Ecology
53
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches...
53