10万年の氷河期のサイクルが特定され,温度,二酸化炭素,軌道離心率に遅れがあることが判明しました
1Department of Earth Sciences, Godwin Laboratory, University of Cambridge, Pembroke Street, Cambridge CB2 3SA, UK. E-mail: njs5@cam. ac.uk.
まとめ
氷河期の10万年周期は,氷床のダイナミクスではなく,地球規模の炭素循環によって引き起こされる. 大気中の二酸化炭素濃度の変化は,軌道特異性によって影響を受け,このリズムを制御します.
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
- 地質化学 地質化学
- 気候科学 気候科学
背景:
- 深海の沈殿体酸素同位体 (デルタ 18 O) は,伝統的に氷河期と関連付けられている10万年周期が支配的であることを示しています.
- ベンティック海域デルタ ((18) O記録は,氷の量と深水の温度変動の両方によって影響を受けます.
研究 の 目的:
- 氷の体積成分を深海の沈殿物デルタから隔離するために.
- 10万年周期の気候サイクルを駆動する要因を調査する.
主な方法:
- 南極の氷 (Vostok) の大気中の酸素から軌道調整のデルタ{18) Oの記録を利用した.
- 氷の量,深水の温度,大気デルタ (ドール効果) の分離した信号.
主要な成果:
- この10万年の氷の量は大気中の二酸化炭素,ヴォストークの気温,深水の温度に遅れをとっている.
- これらの変数は軌道離心率と同期しています.
結論:
- 気候の10万年周期は,主に氷床のダイナミクスによって引き起こされるわけではありません.
- 軌道特異性に対する地球炭素循環の反応は,大気中のCO2を変化させ,おそらくこのリズムを生成します.
関連する概念動画
The Carbon Cycle
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.
Global Climate Change
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.
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
The Fossil Record
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...
Radioactive Decay and Radiometric Dating
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.
Microbes and Climate Change
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...


