Younger Dryasの変動は,海洋循環の変化なしに説明可能な大気中の放射性炭素によるものです
Goslar1, Arnold, Tisnerat-Laborde
1Institute of Physics, Silesian Technical University, Gliwice, Poland. goslar@zeus.polsl.gliwice.pl
Nature
|March 8, 2000
まとめ
若干ドライア期における大気中の放射性炭素 (14C) レベルは,以前考えられていたよりも低いものでした. 新しい湖の堆積物データは,海洋の変化ではなく,太陽活動がこれらの放射性炭素の変動を引き起こしたことを示唆しています.
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 放射性炭素年代測定法による年代測定
- 海洋学 海洋学 海洋学
背景:
- 大気中の放射性炭素 (14C) の濃度は,宇宙線生成と深海のような貯水池との炭素交換の影響を受けています.
- ホロセーン14Cの変動は,主に太陽の磁場変動と関連しています.
- 以前の研究では,海洋の換気が弱まったため,若いドライアス時代に高気温14Cが示唆されていた.
研究 の 目的:
- 若干ドライアス期の大気中の放射性炭素濃度を高解像度で再構築する.
- この寒冷期における14Cの変動の原因を再評価する.
主な方法:
- ポーランドのゴシャッツ湖とペレスピルノ湖の年次層状の湖の堆積物の分析.
- 高解像度の放射性炭素年代測定法による堆積物核の年代測定.
主要な成果:
- ユング・ドライアスの初期に再構築された14Cの最大値は,以前に推定されたよりも低かった.
- 観測された14Cの変動は,太陽活動の変化に起因する可能性がある.
結論:
- この研究は,若いドライアス期における深海の換気が著しく減少したという解釈に異議を唱えている.
- 発見は,太陽活動が,以前に受け入れられていたよりも,若いドライアスの14C変動により重要な役割を果たしたことを示唆しています.
関連する概念動画
The Carbon Cycle
32.8K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
32.8K
The Sulfur Cycle
41.6K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
41.6K
What is Climate?
17.5K
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
17.5K
Global 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
Radioactive Decay and Radiometric Dating
34.6K
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
34.6K
Microbes and Climate Change
91
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
91


